Acetylcholine metabolism in the central nervous system

Abstract

THE physiological evidence for the existence of a relationship between potassium ions and acetylcholine liberation in nervous structures [Brown & Feldberg, 1936; Feldberg & Guimarais, 1936; Beznak, 1934] led us to examine the effects of changes of potassium ion concentration on the synthesis and liberation of acetylcholine in brain tissue in vitro. The results have thrown new light on the nature of the dynamic equilibria, involving acetylcholine metabolism, which exist in the central nervous system. The present communication is concerned with a description of these results and of their consequences. TECHNIQUE Estimation of acetylcholine. The ester was estimated by measuring the con- traction of the eserinized longitudinal muscle from the dorsum of a leech as recorded on a slowly revolving smoked drum. The contraction was compared with those caused by known quantities of acetylcholine chloride. All results are given in terms of acetylcholine chloride per g. tissue. Details of the estimation are given by Quastel et al. [1936].