[Effect of hydrolases and digitonin on the electrophysiological characteristics of the neurons of the snail, Helix pomatia].

Studies have been made on the effect of trypsin, chymotrypsin, pronase, lipases, hyaluronidase and digitonin on electrophysiological properties of the neurons of the snail H. pomatia under external application. Proteases and lipases gradually depolarize the neuronal membrane, decrease the amplitude and prevent the onset of action potentials, initially increase and then decrease the membrane resistance. The decrease in the membrane resistance coincides with the period of maximum inhibition of resting and action potentials in the neurons. The enzymes studied do not affect the membrane capacitance. Changes in electrophysiological characteristics induced by the enzymes are partially reversible provided the preparation is soaked in Ringer's solution for a sufficient time. Digitonin rapidly and irreversibly depolarizes the membrane, decreases its resistance and blocks action potentials. Hyaluronidase does not significantly affect neuronal electrophysiological properties when applied solely, but facilitates the development of changes during subsequent effect of proteases.