Figure 11.

ABR and DPOAE analyses demonstrate reduced auditory sensitivity in Vangl2 CKOs. A, The averaged ABR waveform collected from littermate control and Vangl2 CKO mice between 6 and 8 weeks of age in response to click stimuli. CKO animals have decreased waveform amplitude and increased response threshold. B, The threshold of the ABR response to click stimuli or tones at fixed frequencies. C, The peak amplitude of ABR wave 1 measured from P1 (arrow in A) to N2 (arrowhead in A) in response to clicks or tones of increasing sound intensity. The amplitude of the response is reduced for all stimuli. D, DPOAE measurements of the amplitude of the distortion product in response to f2 stimulus of increasing sound pressure level. The decreased amplitude of the distortion product in Vangl2 CKO animals suggests that hearing deficits in these animals stem from changes in OHC activity and/or function of the cochlear amplifier. In each graph, the responses of Vangl2 CKO animals are red. The number of mice assayed for ABR is n = 10 for controls and n = 8 for CKOs, and for DPOAEs is 8 for controls and n = 5 for CKOs. Error bars show SD, and asterisks indicate statistical significance for differences between littermate controls and Vangl2 CKOs using two-tailed Student's t test with unequal variance (*p < 0.05, **p < 0.005).