Figure 8.

Effects of local gabazine injection on directly evoked spikes of a GPi neuron. A, Raw traces to local repetitive stimulation (40 μA, 100 Hz, 10 pulses) with long (top) and short (bottom) time scales under control conditions. Twenty consecutive traces were superimposed. Arrows with dotted lines indicate the timing of local stimulation (time 0 in the bottom traces). Arrowheads indicate directly evoked spikes. Repetitive high-frequency stimulation failed to evoke spikes (from sixth to 10th stimuli). B, Raw traces after local gabazine injection. Gabazine injection decreased failure rate, and each stimulus successfully evoked spikes (fifth, ninth, and 10th stimuli).