Effects of the duration of the rest period on IPSC amplitude and PPR. A, PPR change during LFDAR is independent of the duration of the rest period. A1, Mean values of I1 from n experiments plotted against the stimulus number during LFDAR after three distinct rest periods. A2, Corresponding values of PPR. B, Minor PPR changes during LFDAR are similar to those observed during LFD (except for the first response) and appear fixed to stimulus number. B1, Mean values of I1 from n experiments plotted against the stimulus number during LFD (same data as in Fig. 2D) and LFDAR (rest, 900 s; same data as in Fig. 5A1). B2, Corresponding values of PPR. For A1 and B1, IPSC amplitudes were normalized to the average IPSC amplitude determined during the plateau of LFD. Error bars indicate SEM.