Effects of ethanol on passive avoidance behavior in the mouse: involvement of GABAergic mechanisms.

A passive avoidance methodology was used to test the effect of ethanol, and its interference with GABAergic mechanisms, on memory in male CD1 mice. Retention performance was reduced in a dose-related manner, by ethanol and by muscimol, a GABA agonist, while it was increased by the GABA antagonists picrotoxin and bicuculline. These effects were evident when treatments were carried out immediately, but not 120 min, after training, suggesting that they were due to a specific action of the drugs on the time-dependent memory consolidation process. The ethanol-induced reduction of retention performance was enhanced by muscimol and decreased by picrotoxin and bicuculline administrations. Taken together the results confirm the involvement of a GABAergic mechanism in memory consolidation and demonstrate that it underlies the negative effect of ethanol on passive avoidance behavior in the mouse.