Reduction of voltage-dependent currents by ethanol contributes to inhibition of NMDA receptor-mediated excitatory synaptic transmission

Previous studies have shown inhibitory effects of EtOH on NMDA receptor-med iated synaptic transmission in several brain regions. We examined this effe ct of EtOH under both current clamp and voltage clamp conditions in the bas olateral amygdala because of the putative role of the amygdala in mediating anxiolytic effects of EtOH. We found that EtOH reduced NMDA receptor-media ted synaptic responses. In addition, we found that NMDA receptor-mediated d epolarizations could also activate a voltage-dependent regenerative potenti al which was also sensitive to EtOH. Pharmacological characterization of th is current was consistent with a high-threshold Ca2+ current. This current also exhibited a pronounced tendency towards transient enhancement upon wit hdrawal of EtOH. (C) 1999 Elsevier Science B.V. All rights reserved.