(A, C, E, F) Bath application of nicotine in the presence of DNQX (20 μM), AP5 (40 μM), and bicuculline (10 μM) induced inward currents in interneurons voltage-clamped at −70 mV. (A) The response elicited by bath application of 10 μM nicotine is shown. (B) Low concentrations of nicotine found in cigarette smokers induced inward currents and the amplitude of nicotine-induced currents varied among interneurons. (C) Successive bath application of nicotine with increasing concentrations increased the amplitude of inward currents rather than desensitizing the non-α7 nAChRs. (C, D) Nicotine induced inward currents in a dose-dependent manner and DHβE blocked the nicotine-induced inward currents. (E) Bath application of choline (5 mM) onto nicotine-responding interneurons had no effect. (F) MLA (100 nM) had no significant effect on nicotine-induced inward currents.