Flumazenil can inhibit the enhancement of GABA currents by isoflurane. A, Representative traces of GABA receptor activation in multiple treatment conditions. Black bars represent co-application of isoflurane; orange bars represent co-application of increasing flumazenil concentrations (from left to right: 0.1, 0.3, 1.0, 3.0, 10, 30 μM). Inset is an overlay of EC20 GABA response (black), EC20 GABA response potentiated by isoflurane (280 μM), and the flumazenil antagonized EC20 GABA response potentiated by isoflurane. B, Summative dose-response curve for the effect of increasing doses of flumazenil on isoflurane enhanced EC20 response (n = 34 cells). Error bars represent SEM.