Biphasic effects of ethanol on acetylcholine release in the rat prefrontal cortex.

Low doses of ethanol (0.5 g/kg i.p.) increased, while higher doses (1 g/kg i.p.) reduced acetylcholine (ACh) release in the rat prefrontal cortex (PFC). Ethanol (50-300 mM) applied in the nucleus basalis through a second dialysis probe caused concentration-dependent biphasic changes in prefrontocortical ACh release. Ethanol apparently acts on cholinergic fibers to modulate ACh transmission in the PFC. These results could be of relevance for the bidirectional modulation of working memory by ethanol.