Cochlear potentials in the Bronx waltzer mutant mouse

The Bronx waltzer mutant mouse has a unique cochlear abnormality in which the outer hair cells appear normal but the inner hair cells are absent. Potentials recorded from the round window indicate that the gross cochlear nerve action potential is very small or absent and cochlear microphonics are present but of small amplitude. Positive and negative summating potentials can both be recorded, indicating that mammalian outer hair cells are capable of producing both positive and negative DC potentials.