Development of Hearing in the Normal Cba-J Mouse: Correlation of Physiological Observations with Behavioral Responses and with Cochlear Anatomy

Abstract

In the mouse, cochlear potentials appeared first with narrow ranges on the eighth day after birth and gradually increased by the fourteenth day when the responses attained adult values. Nerve action potentials as recorded from the round window appeared on the ninth day when cochlear potential ranges extended from 0.6 to 8 kc. R₁ R₂ as recorded from the eighth nerve appeared one day after the N₁ N₂ is recorded from the round window membrane. The Preyer responses appeared when action potentials could be recorded from the eighth nerve. The development anatomical changes in the mouse are similar to those found in the albino rat. The structures in the cochlea are present at birth and then there is gradual maturation of the organ of Corti, reachiag adult size by the eighth to tenth day. The mature configuration of the cochlea by the tenth day correlates with the behavioral and physiological findings.