Figure 3.

Averaged responses of a short-pass neuron to varying tone burst durations (A) and changes in carrier frequency (B). A, Inhibition was isolated by examining the responses to 20 ms, 300 Hz tone bursts (gray trace), a stimulus that evoked minimal excitation; stimulus carrier frequency was 750 Hz, the BEF, for all other traces. B, Responses to 20 ms (top) or 200 ms (bottom) tone bursts (frequencies shown), recorded under negative (−0.04 nA) or positive (+0.04 nA) current clamp, respectively. The time course of excitation with a 20 ms tone burst was similar to the time course of inhibition with a 200 ms tone burst. C, Time-expanded view of the initial responses to 800 Hz tone bursts (region denoted by the dashed box in B) to show latencies of excitation and inhibition. Depolarization peaks in negative current-clamp recordings are mirrored by corresponding peaks in positive current clamp (dashed lines). The stimulus amplitude was 65 dB SPL, threshold was 54 dB SPL, and the resting potential was −87 mV.