Differential roles of NMDA and non-NMDA receptor activation in induction and maintenance of thermal hyperalgesia in rats with painful peripheral mononeuropathy

摘要: Abstract Central activation of excitatory amino acid receptors has been implicated in neuropathic pain following nerve injury. In a rat model painful peripheral mononeuropathy, we compared the effects non-competitive NMDA reeptor antagonists (MK 801 and HA966) non-NMDA receptor antagonist (CNQX) on induction maintenance thermal hyperalgesia induced by chronic constrictive injury (CCI) common sciatic nerve. Thermal to radiant heat was assessed using foot-withdrawal test NMDA/non-NMDA were administered intrathecally onto lumbar spinal cord before after Four daily single treatments with 20 nmol HA966 or CNQX beginning 15 min prior ligation (pre-injury treatment), reliably reduced CCI rats days 3, 5, 7 10 ligation. also receiving post-injury treatment (20 80 nmol) MK (5 day 3 when well developed. contrast, failed reduce potentiate rats. Moreover, multiple utilizing same dose regime as employed for pre-injury attenuated but only began 1 24 h (but not 72 h) The results suggest that may have differential roles injury, mechanisms underlying be associated mediated central abnormalities.