Three electrophysiological classes of guinea pig sympathetic postganglionic neurone have distinct morphologies

Abstract

Sympathetic postganglionic neurones can be differentiated electrophysiologically into three classes (phasic, Ph; tonic, T; and long-afterhyperpolarising, LAH) based on their potassium channel expression and consequent differences in excitability. We tested whether neuronal morphology differs between these classes. Neurones in coeliac, inferior mesenteric, and lower lumbar paravertebral ganglia of guinea pigs were filled with biocytin during in vitro experiments in which electrical properties were recorded. The dimensions of somata and dendrites were measured in approximately equal numbers of stained neurones of each class. The three electrophysiological classes were distinct in terms of soma..