Single-channel currents activated by 0.1 μM glutamate and 50 μM glycine in outside-out patches from cells expressing GluN1/GluN2A (A,B) or GluN1/GluN2B (C,D) NMDA receptor subunits in the absence (A,C) and the presence (B,D) of ethanol (EtOH), 156 mM (B) or 150 mM (D). Channel openings are downward. Scale bars in A apply to all records.