Chemical transmission between rat sympathetic neurons and cardiac myocytes developing in microcultures: evidence for cholinergic, adrenergic, and dual-function neurons.

Abstract

Electrophysiological studies were made on microcultures (300-500 .mu.m in diameter) in which solitary sympathetic principal neurons from newborn rats grew on previously dissociated rat heart cells. Some neurons inhibited, some excited and others first inhibited and then excited the cardiac myocytes. Application of drugs provided evidence for secretion of acetylcholine by the 1st group, catecholamines by the second, and both acetylcholine and catecholamines by the third. Solitary neurons which inhibited the myocytes usually excited themselves at nicotinic synapses (autapses).