ETHANOL ENHANCEMENT OF GABA-INDUCED CL-36(-) INFLUX DOES NOT INVOLVE CHANGES IN CA2+

The effect of changes in intracellular Ca2+ on ethanol enhancement of GABA-mediated Cl-36(-) influx was investigated in mammalian cortical n eurons in culture. Ethanol potentiated the effect of submaximal concen trations of GABA on the Cl-36(-) influx, and at 50 mM ethanol directly activated Cl-36(-) influx in these neurons. Pretreatment of the neuro ns with dantrolene (an agent that depletes intracellular Ca2+) and the Ca2+ ionophore, A 23187, did not alter the effect of GABA or ethanol enhancement of GABA-mediated Cl-36(-) influx. Together, these results suggest that changes in intracellular Ca2+ are not involved in ethanol modulation of GABA(A)ergic responses in cortical neurons.