Response properties of SON neurons to acoustic stimulation are modulated by glycinergic inhibitory inputs. A: example of SON acoustic responses during local iontophoresis of strychnine. PST histograms are shown for the control, strychnine, and recovery conditions. Spike count increases at all intensities in the presence of strychnine and then recovers when iontophoresis of the drug is turned off. For this cell, the input-output function that was nonmonotonic in the control condition became monotonic during strychnine treatment. Black bar indicates 50-ms stimulus tone. Spike counts are the total for entire PST histogram shown. Bi: rate-level functions for control, strychnine, and recovery conditions from the same cell as in A. Bii: population data for glycine receptor (GlyR) block. GlyR block significantly increases the peak spike rate (re: the peak control rate; *P < 0.05). GlyR block did not significantly affect the slope of the dynamic range.