Effects of ethanol on acetylcholine and GABA release: differences in the role of potassium.

Ethanol inhibited electrically stimulated [3H]ACh release from cortical brain slices, but not when release was stimulated by high potassium. In contrast, ethanol was ineffective on electrically stimulated release of [14]GABA from cortical brain slices, but inhibited potassium-induced release. Ethanol also significantly inhibited potassium-stimulated [14C]GABA release from cortical synaptosomes. These data suggest that ethanol selectively inhibits GABA release from neurons by a specific effect on potassium conductance, and inhibits ACh release by a selective effect on Na+ conductance.