Increase in chloride ion permeability across the nerve cell membrane after the endogenous antigen S-100 incorporation

36Cl fluxes through microdissected Deiters' neuronal membranes have been studied in a microchamber device simulating the extra- and intracellular compartments. GABA stimulates Cl- permeability through the membranes by 24%. Also, S-100/Ca2+ incorporation into the Deiters' membrane increases 36Cl- permeation to a similar extent. The two effects do not appear to be additive. This circumstance is interpreted as indicating that S-100/Ca2+ exerts its effects via postsynaptic GABAA receptor complexes.