CURRENTS AND CHANNELS IN THE PRESYNAPTIC NERVE-TERMINAL

Synaptic transmission is a key element in neuronal communication in th e nervous system. It is determined by two basic sets of processes: rel ease of transmitter from the presynaptic nerve ending and the detectio n and response by the postsynaptic cell. The release of transmitter is crucially dependent on the interplay among the ion channels in the su rface membrane of the presynaptic terminal. In this article we describ e the methods used in the study of the ion channels in secretory nerve endings and present the 16 calcium, sodium, chloride, cationic and po tassium ion channels discovered in various preparations. We speculate about the physiological and pathophysiological roles of some of these ion channels.