Responses of TH1-AC1, B-LC3, and B-LI4 to different PI that were varied within a sequence of sound pulses or pairs of pulses; PD kept constant at 21 ms. A, Recording of TH1-AC1 (top) and PSTH (4 ms/bin) with averaged instantaneous spike frequency (bottom; N = 1 female, n = 40 sequences). B, Recording of B-LC3 (top) and PSTH (4 ms/bin) with averaged instantaneous spike frequency (bottom; N = 1 female, n = 10 sequences). C, Averaged synaptic activity of B-LI4 to single pulses (bottom) and pairs of sound pulses with PI ranging from 5 to 60 ms (N = 1 female, n = 16 for single pulses, and n = 4 for pairs of pulses).