  Outer hair cells in the inner ear is important for the sensitivity, frequency
selectivity, and dynamic range of the mammalian ear. Such a physiological role
of outer hair cells is thought to be based an amplifying effect of those cells,
which have mechanosensitive their hair bundles and motile cell body embedding
prestin, a membrane protein with electromechanical coupling at high density.
Mechanical power production by outer hair cells were previously evaluated based
on an assumption that the intrinsic transition rates of this motile protein is
faster than the operating frequency. This report generalizes the previous
treatment by incorporating intrinsic transition rates of the motile membrane
protein. It was found that the transition rates attenuates mechanical power
production of an outer hair cell such that viscous drag cannot be counteracted
beyond the characteristic frequency of gating.

Biological Physics