Bidirectional transduction by haircells

Abstract

Given the two-port description of a hair cell from Weiss [Hear. Res. 7, 353–360 (1982)], with the Davis model for the angle-dependent conductance representing the transduction channels [Leong and Weiss, Hear. Res. 20, 175–195 (1985)], and the data of Crawford and Fettiplace [J. Physiol. 364, 359–379 (1985)], Howard and Hudspeth [Neuron 1, 189–199 (1988)], and Holton and Hudspeth [J. Physiol. 375, 195–227 (1986)], analysis shows that (1) the feedback inherent in the two-port must be positive, and (2) degenerative (outward-flowing) channels must be present. The static nonlinear behavior of the system, and the small and large signal dynamics, have been studied. The system displays Q multiplication at low signal levels, bandwidth increase with signal level, a compressive nonlinearity at CF, and continuous oscillations if the parameters are slightly misadjusted—all well-documented physiological phenomena.