Ionic Basis of Action Potentials and Bursting Activity in the Hydromedusan Jellyfish Polyorchis Penicillatus

Abstract

Knowledge of coelenterate cellular neurophysiology is extremely limited despite the amount of attention this phylum has received from physiologists (cf. Josephson, 1974). However, the recent discovery that reliable intracellular recordings can be obtained from motor neurones in the inner nerve ring of the hydromedusan jellyfish Polyorchis penicillatus (Anderson & Mackie, 1977) presents us with a preparation with which to study cellular events in these organisms. This report describes results from a series of experiments designed to investigate the ionic basis of action potentials in this preparation.