Effects of GABA antagonists on inhibitory avoidance

Experimental data indicate that GABA is involved in memory processes. However there are marked inconsistencies in the reported effects of interference with GABA synaptic activity on memory consolidation of aversively-motivated tasks. Both amnesia and improvement of performance have been reported after treatment with GABA antagonists. These contradictory effects could be explained by procedural differences in training. To test for this possibility rats were trained in passive avoidance using two levels of footshock and injected with a wide range of doses of picrotoxin and bicuculline. Picrotoxin did not modify the conditioned response while bicuculline induced amnesia only with the lower doses at both low and high footshock intensities. It was concluded that GABA is involved in memory consolidation, and that the conflicting results in the literature are indeed due, in part, to procedural differences, and also to the mode of action of these drugs.