Effects on GPi neuron responses of selective elimination of the cortico-STN projection.

<p>A: Typical examples of peri-stimulus time histograms (PSTHs; bin width of 1 ms, summed for 100 stimulus trials) in monkey G before (1) and after (2) IT injections into the SMA. Electrical stimulation in the SMA was given at time = 0 (arrows). In each PSTH, the mean firing rate and statistical levels of P<0.05 (one-tailed <i>t</i>-test) calculated from the firing rate during 100 ms preceding the onset of SMA stimulation are indicated by the solid white line (mean), broken black line (upper limit of P<0.05), and broken white line (lower limit of P<0.05), respectively. The excitatory and inhibitory responses are represented in red or cyan color, respectively. The amplitude of each response was defined as the number of spikes in the colored area. B: Typical examples of spontaneous activities denoted by slow traces of digitized spikes and autocorrelograms (bin width of 0.5 ms) in monkey G before (1) and after (2) IT injections into the SMA.