灵长类研究中心知识库

Paracetamol has recently been suggested to affect emotion processing in additionto alleviating pain in humans. We investigated in adult male Hannover–Wistar ratswhether acute intraperitoneally administrated paracetamol affects behavior in testsmeasuring anxiety, mood, motor activity, and memory. Unoperated rats received sal-ine or a low (50 mg/kg) or high (300 mg/kg) dose of paracetamol, while rats with aspared nerve injury (SNI) model of neuropathy and sham-operated rats received sal-ine or the low dose of paracetamol. Rats were tested on open-field (OFT), elevatedplus-maze (EPM), light-dark box (LDB), novel-object recognition (NOR), sucrose pref-erence, rotarod, and monofilament tests. In unoperated rats, both the low and highdose of paracetamol reduced line crossings, and grooming time in the OFT, andnovel preference in NOR. The high dose of paracetamol increased the time spent inthe closed arm in EPM, reduced the number of rearings and leanings in OFT, thetime spent in the light box in LDB, and sucrose preference. Paracetamol had no sig-nificant effect on the rotarod test measuring motor activity. The low dose of parac-etamol suppressed mechanical pain hypersensitivity in SNI rats, without influencingpain behavior in sham-operated rats. Saline- but not paracetamol-treated SNI ratsspent more time than sham-operated rats in the closed arm in the EPM test.Together the results suggest that a high dose of paracetamol increases anxiety-likeand anhedonic behavior, and impairs recognition memory in unoperated controls,while in neuropathy, a low dose of paracetamol reduces nerve injury-associatedanxiety probably by reducing neuropathic pain.