Fig. 5.

As shown in a single experiment (A, top) and in the summary data (A, bottom), application of nicotine at concentrations of either 1 or 10 μM did not significantly alter the peak amplitude of the GABAergic current evoked by LGPi electrical stimulation. However, nicotine, at a concentration of 100 μM, significantly inhibited the evoked GABAergic current (A, top, single experiment; A, bottom, summary data). As shown in a single experiment (B, top) and in the summary data (B, bottom), application of the non α7 receptor antagonist DHβE did not alter the evoked GABAergic response and DHβE also did not alter the inhibitory effect of nicotine on the evoked GABAergic current. However, the inhibitory effect of nicotine was antagonized with α-Bgtx, an α7 receptor blocker, whereas α-Bgtx alone did not evoke any effect on the inhibitory GABAergic current evoked by LGPi stimulation, as shown (C, top, single experiment; C, bottom, summary data).