Loss of glycine receptors containing the α3 subunit compromises auditory nerve activity, but not outer hair cell function

Before AT, DPOAE thresholds were slightly, but significantly lower, and DPOAE amplitudes were slightly larger in Glra3−/− as compared to Glra3+/+ mice. While click- and f-ABR thresholds were similar in both genotypes before AT, threshold-normalized click-ABR wave I amplitudes were smaller in Glra3−/− mice as compared to their wildtype littermates. Following AT, both the decrement of ABR wave I amplitudes and the delay of wave I latencies were more pronounced in Glra3−/− than Glra3+/+ mice. Accordingly, correlation between early click-evoked ABR signals (0-2.5 ms from stimulus onset) before and after AT was significantly reduced for Glra3−/− as compared to Glra3+/+ mice. In summary, these results show that loss of α3-GlyRs compromises suprathreshold auditory nerve activity, but not outer hair cell function.