Flumazenil exhibits weak agonist effects on the GABA receptor in the absence of GABA. A, Representative traces of chloride currents through the GABA receptor evoked by application of increasing flumazenil concentrations (orange bars, from left to right: 0.1, 0.3, 1.0, 3.0, 10, 30 μM) followed by the response of the GABA receptor to a 10 μM application of GABA (EC20) for comparison. B, Summative dose-response curve for flumazenil’s effect on the GABA receptor in the absence of GABA (n = 10 cells). Error bars represent SEM.