Figure 4

Accumulation effect of responses in region β (at the best ISI) (A-C) and its durability (D, E). A, B: Peri-stimulus time histogram (bin width = 5 ms) (A) and sequential plot of the number of spikes (# spikes) involved in each discharge cluster (every discharge cluster was elicited by single clicks) (B). C: Population data (mean ± SD) in the same format as B except that #spikes was normalized to that involved in the 1st discharge cluster (= control level; same as followings). D: The procedure for measuring the responsivity after the trains that were delivered at the best ISI: a single click (= probe stimulus; arrows) was presented at either 1.0 s (I), 1.8 s (II) or 3.6 s (III) after the termination of the train. E: Population data of the normalized #spikes measured according to D. *P < 0.05 (paired t-test). Note (1) responsivity gradually declined with the progression of the train (C), and (2) the response degeneration lasted for 1.0-1.8 s after the termination of the train (E).