Dynamic Characteristics of the Force Generated by the Outer Hair Cell Motility in the Organ of Corti (Theoretical Consideration)

Abstract

The force generated by the outer hair cell (OHC) motility greatly contributes to the high sensitivity and sharp tuning of the cochlea. However, the dynamic characteristics of this force in vivo have not yet been clarified. In this study, a finite-element model of the organ of Corti including OHCs was constructed, and the magnitude of the force generated by the OHC motility and its phase relative to the deflection of the OHC's hair bundle were obtained by comparing the numerically obtained gain of the basilar membrane vibration with experimental data. Consequently, it was found that the phase delay of the force is within the range between 45deg. and 180deg. and that the magnitude of the force is nearly 1.8nN/nm. Moreover, it was suggested that the electric potential which drives the OHC is likely to be the extracellular potential rather than the receptor potential.