Dynamics of ion currents in the membrane of the isolated mollusc neuron under high pressure.

The action of helium (up to 101 abs. atm.) under high pressure on ionic currents through the cellular membrane was studied in experiments on isolated neurons of a gastropod. A method of intracellular dialysis which is new for physiological investigations under hyperbaric conditions was used. A substantial decrease in the inward (sodium) current with increased pressure was found. Its amplitude was decreased by 10-15% at 25 abs. atm. and by 64% at 101 abs. atm. as compared with the control. At the same time, a shift in the currentvoltage characteristics along the abscissa was not observed. Significant changes in the outward (potassium) current were not appreciable. The inhibition of the sodium current observed in these experiments with increased pressure is associated with a possible change in the structure of the cell membrane under the influence of pressure; this leads in its turn to shifts in the functioning of the membrane components participating in the generation of the nerve impulse.