title: Differential effects of NMDA and non-NMDA receptor antagonists on spinal cutaneous vs muscular nociception in the cat.
abstract: To investigate the role of glutamate receptor subtypes in spinal transmission of nociceptive cutaneous and muscular afferents, nociceptive responses of WDR neurones in laminae IV-VI of the dorsal horn produced by noxious cutaneous and muscular stimulation were tested in the cat. With microelectrophoretic administration of the NMDA receptor antagonists, 2-amino-5-phosphonovalerate (APV) and ketamine, cutaneous nociceptive responses were preferentially reduced by more than 50%. In contrast, the non-selective excitatory amino acid receptor antagonist kynurenate (Kyn) markedly reduced both cutaneous and muscular nociceptive responses. The difference between APV- and Kyn-induced reductions of muscular nociceptive responses is statistically significant (chi 2-test, p < 0.01). The results suggest that NMDA and non-NMDA receptors preferentially mediate transmission of nociceptive information originating in skin and muscle, respectively.
authors.affiliation: Shanghai Brain Research Institute, Chinese Academy of Sciences.
authors.forename: X J
authors.initials: XJ
authors.lastname: Song
authors.forename: Z Q
authors.initials: ZQ
authors.lastname: Zhao
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002415:Cats; D007478:Iontophoresis; D007649:Ketamine / Q000494:pharmacology; D007736:Kynurenic Acid / Q000494:pharmacology; D009132:Muscles / Q000502:physiology*; D009412:Nerve Fibers / Q000187:drug effects; D009619:Nociceptors / Q000187:drug effects*; D017459:Receptors, Amino Acid / Q000037:antagonists & inhibitors; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D012879:Skin Physiological Phenomena; D013116:Spinal Cord / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D017459:Receptors, Amino Acid; D016194:Receptors, N-Methyl-D-Aspartate; D007649:Ketamine; D015763:2-Amino-5-phosphonovalerate; D007736:Kynurenic Acid