[Physiology and pharmacology of the Na and K channels of axon membranes].

The electrical activity of axons is due to changes in Na and K membrane permeabilities. Ions cross the membrane through specific pathways (Na et K channels). Ionic channels are transmembrane proteins forming pores whose openings are controlled by the membrane potential. Their properties are mainly studied by electrophysiological (current recording under voltage clamp conditions) and biochemical (characterization of toxin binding sites) techniques. The purpose of these studies is to determine the structure of these channels and to delineated their mode of functioning.