Effect of ethanol on potassium-stimulated and electrically stimulated acetylcholine release in vitro from rat cortical slices.

Abstract

The effects of ethanol (EtOH) on potassium and electrically stimulated acetylcholine (ACh) release were compared in rat cerebral cortical slices in vitro. ACh was measured by pyrolysis - gas-liquid chromatography (GLC). Paired samples were incubated with and without 0.11 M EtOH. In the potassium stimulation experiments, cortical slices were serially incubated for three 45-min periods in normal incubation medium followed by two periods in medium containing either 15 or 27 mM K+. In the electrical stimulation experiments, the cortical slices were similarly incubated for three 30-min periods without stimulation followed by two periods of electrical (10 HZ) stimulation. ACh output rose 20% at 15 mM K+ and 160% at 27 mM K+. Ethanol had no effect on spontaneous ACh release and did not influence the ACh response to high K+ stimulation. Electrical stimulation approximately doubled the ACh output but EtOH reduced electrically stimulated ACh relese by 50--80%. These findings are compatible with the view that EtOH acts primarily on Na+ influx during the action potential.