Figure 10.

Effects of ChTx with and without AgTx on PPR. A, Repetitive firing of presynaptic and postsynaptic FSNs (FSN1 and FSN2, respectively). Arrowheads indicate autaptic responses. B, C, Ten consecutive traces (gray) with averaged traces (black; B) and the scaled traces (C) in the control and during ChTx application. D, ChTx alone induced little change in the PPR (n = 7). E, Repetitive firing of presynaptic and postsynaptic FSNs (FSN3 and FSN4, respectively). F, Effects of ChTx on uIPSCs in the presence of AgTx in the FSN3→FSN4 connection shown in E. G, Scaled traces in the control condition and during application of AgTx without and with ChTx. Note the facilitative effect of ChTx on the PPR. H, uIPSC amplitude during AgTx and AgTx and ChTx (n = 10). I, ChTx with AgTx facilitated the PPR (n = 10). *p < 0.05, paired t test.