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	The effects of aging on the strength of surround suppression of receptive field of V1 cells in monkeys
	Fu Y1,2; Wang XS1; Zhou YF4; Ma YY*1; Wang YC3,4; Zhang J1; Liang Z5; yuanma0716@vip.sina.com
	2010
发表期刊	NEUROSCIENCE
卷号	169期号:2页码:874-881
合作性质	其它
摘要	The surround suppression of the receptive field is important for basic visual information processing, such as orientation specificity. To date, the effects of aging on the strength of surround suppression are not clear. To address this issue, we carried out extracellular single-unit studies of the receptive field properties of cells in the primary visual cortex (area V1) in young and old rhesus (Macaca mulatta) monkeys. When presented with the oriented central stimulus, we found that cells in old animals showed reduced orientation and direction selectivity compared with those in young animals. When presented with the oriented central stimulus together with the optimal surround stimulus, more selective cells {orientation bias (OB) >= 0.1; a bias of 0.1 is significant at the P<0.005 level} in animals of both ages showed reduced orientation selectivity compared with the experiment that presented only the oriented central stimulus. When presented with the optimal central stimulus together with the oriented surround stimulus, cells in old animals showed reduced orientation and direction selectivity compared with young animals. Moreover, broadly tuned cells (OB<0.1) in old animals exhibited significantly reduced suppression indices that quantified the strength of the surround suppression of the receptive field, when compared with those in young animals. These results suggest that aging may seriously affect the surround suppression of the receptive field of V1 cells. Thus, the decreased strength of surround suppression of the receptive field may be one possible reason for the decreased stimulus selectivity of V1 cells previously found in the senescent brain. This work will contribute to an understanding of the physiological mechanisms mediating surround suppression of the receptive field. (C) 2010 IBRO.
关键词	Primary Visual Cortex Orientation Selectivity Receptive Field Surround Inhibition Rhesus Monkey
资助者	This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018).
语种	英语
资助者	This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018). ; This study was supported by grants from NIH/NIA R01 AG 17922, National Science Foundation of China (NSFC 30470553, 30530270, 30670669 and 30770700), 973 pro- gram (2005CB522803, 2007CB947703), 863 program (O7013810, 2006AA02A116), the Major State Basic Research of China (NO2003CB716600), Chinese-Finnish International Collaboration Project-neuro (30621130076), Program of CASC (KSCX1-YW-R-33, YZ200737, KSCX2-YW-R-261), National Key Technologies R&D Program and Yunnan Science and Technique Program (2006PT08- 2), the research foundation of Yunnan University (2008YB007), the Science Foundation of Education Department of Yunnan (09Y0034), and the special fund of the “211” third phase project of Yunnan University (21134018).
文献类型	期刊论文
条目标识符	http://ir.kiz.ac.cn/handle/152453/9609
专题	认知障碍病理学
通讯作者	yuanma0716@vip.sina.com
作者单位	1.State Key Laboratory of Brain and Cognitive Science, Kunming Insti- tute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China 2.Department of Electronic Engineering, Information School, Yunnan University, Kunming, Yunnan 650091, PR China 3.Evergreen Biotech, Inc. Shangyu, Zhejiang 312300, PR China 4.Department of Neurobiology and Biophysics, School of Life Science, University of Science and Technology of China, Hefei, Anhui 230027, PR China 5.Department of Bio-Medical Engineering, Anhui Medical University, Hefei, Anhui 230032, PR China
推荐引用方式 GB/T 7714	Fu Y,Wang XS,Zhou YF,et al. The effects of aging on the strength of surround suppression of receptive field of V1 cells in monkeys[J]. NEUROSCIENCE,2010,169(2):874-881.
APA	Fu Y.,Wang XS.,Zhou YF.,Ma YY*.,Wang YC.,...&yuanma0716@vip.sina.com.(2010).The effects of aging on the strength of surround suppression of receptive field of V1 cells in monkeys.NEUROSCIENCE,169(2),874-881.
MLA	Fu Y,et al."The effects of aging on the strength of surround suppression of receptive field of V1 cells in monkeys".NEUROSCIENCE 169.2(2010):874-881.

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