PhTX blocks AMPA receptors only with auditory nerve input and not with parallel fiber input. Left, The 50 μm cadmium and kainate alone had no effect on mEPSCs in a bushy cell. The amplitude, rise and decay time, and frequency of events before and after were not significantly different (p < 0.01; Student’s ttest). Center, mEPSCs were abolished completely by 50 μm PhTX in a bushy cell. Right, 50 μm PhTX did not affect mEPSCs in a cartwheel cell. The amplitude, rise and decay time, and frequency before and after were not significantly different (p < 0.01; Student’s t test). Strychnine (1 μm) was present in the bath for the duration of the recording to isolate the mEPSCs. All traces were filtered off-line at 5 kHz for presentation purposes.