[Nature of the membrane depolarization of a nerve cell during the application of protein S-100 antibodies].

Application of antibodies to S-100 protein (the antibody concentration in the micropipette being 0.05 mg/ml) induced 13 +/- 4 mV depolarization of the membrane of snail Helix neurons. Non-immune gamma-globulin used in the control experiments caused no changes in the membrane potential. Antibody-induced depolarization was accompanied by a 2.5 nA inward current which was voltage-independent in the range of membrane potential from 50 to 110 mV. Hyperpolarization observed after the rinsing of antibodies was effectively blocked by a specific blocker of monovalent cation transport, ouabain, at a concentration of 5 X 10(-4) M. The absence of antibody-induced changes in the passive membrane conduction and the activation of electrogenic transport mechanisms after the antibody removal suggest possible involvement of Na, K- ATPase into the effect described.