Figure 4. Mice with hair cells deficient for either β-actin or γ-actin develop distinct forms of progressive hearing loss.

Auditory brainstem response (ABR) thresholds at 6, 18 and 24 weeks of age. (A) Actg1-flox Atoh1-cre mice have near normal ABR thresholds for sound tones between 4 and 22 kHz at 6 weeks of age, but elevated thresholds at all frequencies at 18 and 24 weeks of age. (B) Actb-flox-Atoh1-cre mice have progressive loss of hearing starting with higher frequency sounds.