Proconvulsive effect of the GABAB receptor antagonist, SCH 50911, in rats undergoing ethanol withdrawal syndrome

The present study investigated the effect of the GABA(B) receptor antagonist, SCH 50911 [(2S)(+)-5,5-dimethyl-2-morpholineacetic acid], on the occurrence of seizures in ethanol-dependent rats undergoing ethanol withdrawal syndrome. The acute administration of nonconvulsive doses of SCH 50911 (0, 100, 170 and 300 mg/kg, i.p.) resulted in a dramatic facilitation of spontaneous seizure occurrence. This finding, together with the reported ability of the GABAB receptor agonist, baclofen, to suppress seizures associated to ethanol withdrawal syndrome, suggests that the GABAB receptor may be part of the neural substrate underlying the hyperexcitability of ethanol withdrawal syndrome. (C) 2002 Elsevier Science B.V. All rights reserved.