Figure 6. Thiopental, 30 micro Meter, was preperfused and coapplied with nicotine, 100 or 300 micro Meter, and depression of the peak and steady current was analyzed in the same way as the experiments using nicotine, 30 micro Meter. There were no significant differences in the magnitudes of depression in the peak or steady current among the different doses of nicotine. The numbers of the experiments were six, five, and four for nicotine 30, 100, and 300 micro Meter.