• no signs of vestibular dysfunction (J:174130)

• the tunnel of Corti is less well formed at 4 weeks of age

• absence of stereociliary tip tenting of IHC second tallest row stereocilia indicating disruption of tip links

• some indication of hair cell degeneration in the basal cochlear region at 4 weeks of age

• by 8 and 12 weeks of age signs of hair cell degeneration are clearly apparent in the basal and midcochlear turns

• collapse of the organ of Corti in the basal and midcochlear turns at 8 and 12 weeks of age

• significantly increased threshold at 4 weeks of age

• profound hearing loss at 4 weeks of age

• no signs of vestibular dysfunction (J:174130)

• absence of stereociliary tip tenting of IHC second tallest row stereocilia indicating disruption of tip links

• some indication of hair cell degeneration in the basal cochlear region at 4 weeks of age

• by 8 and 12 weeks of age signs of hair cell degeneration are clearly apparent in the basal and midcochlear turns

• loss of spiral ganglion neurons in the basal and midcochlear turns at 8 and 12 weeks of age

• at 13 weeks of age in the basal cochlear turn, with approximately 50% of OHCs missing in this region

• increased threshold at 24 weeks of age

• later onset and milder than in homozygous mice

• at 13 weeks of age in the basal cochlear turn, with approximately 50% of OHCs missing in this region