title: WDR response profiles of spinal dorsal horn neurons may be unmasked by barbiturate anesthesia.
abstract: The number of WDR (convergent, multireceptive) neurons encountered in the spinal dorsal horn of physiologically intact, awake, drug-free cats has been much smaller than expected (9% in intact, drug-free animals). Control studies in barbiturate-anesthetized or spinal cord transected animals indicate that the dearth of WDR neurons was not just an artifact of the chronic recording technique. In those preparations WDR neurons represented 34% and 61% of the sample, respectively. Initial studies in which the effects of light barbiturate anesthesia on spinal dorsal horn neurons (n = 12) have been examined revealed that a 20 mg/kg dose of pentobarbital can, in some neurons (n = 4), unmask thermally evoked activity that was not present in the intact, drug-free animal. Responses to noxious mechanical stimuli were also enhanced following barbiturate administration. These changes resulted in a reclassification of neural type from low threshold in the intact, awake, drug-free animal to WDR in the anesthetized animal.
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001463:Barbiturates / Q000494:pharmacology*; D002415:Cats; D006358:Hot Temperature; D010812:Physical Stimulation; D012867:Skin / Q000294:innervation; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*
chemical_list: D000777:Anesthetics; D001463:Barbiturates