Evaluation of morphine analgesia and motor coordination in mice following cortex-specific knockout of the N-methyl-D-aspartate NR1-subunit.
Studies have shown that N-methyl-D-aspartate (NMDA) receptors play a critical role in morphine analgesia and motoric processes at different levels of the central nervous system. In this study, we used cortex-specific NR1 knockout (KO) mice (C57BL/6 strain) to elucidate the role of cortical NMDA receptors in morphine analgesia and motor coordination. On post-natal day 20, mice (CTL and KO) received vehicle (saline) or morphine (10 mg/kg) and paw withdrawal latency (PWL) to a noxious thermal stimulus was measured. On post-natal day 21, motor coordination was measured using the rotating pole test. No differences in KO mice were found with respect to PWL following administration of saline or morphine (p>0.05). However, sex-dependent differences were found in motor coordination, with male KO mice showing a greater motor impairment in the rotating pole test than female KO mice (p<0.05). The present results demonstrate that NMDA receptors are involved in both the analgesic effects of morphine and motor coordination, with the existence of sex-related differences in motor coordination.
Quintero
Gabriel C
GC
Neuroscience Center of Excellence, Louisiana State University Health Science Center, New Orleans, LA 70112, USA. gaboquintero2006@yahoo.com
Erzurumlu
Reha S
RS
Vaccarino
Anthony L
AL
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D005260:Female; D006358:Hot Temperature; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D009020:Morphine / Q000494:pharmacology*; D010147:Pain Measurement / Q000187:drug effects*; D004856:Postural Balance / Q000187:drug effects*; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics / Q000502:physiology*; D012727:Sex Characteristics
D000701:Analgesics, Opioid; C409466:NR1 NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; D009020:Morphine