Fig. 6.

Schematic representation of the MET machinery between two adjacent rows of stereocilia comparing the old motor model and revised model of adaptation. (A) In the old model, MET channels are located at both ends of the tip link. Myosin motors are located at the upper tip-link insertion, generate resting tension, and mediate adaptation by climbing and slipping along the side of the stereocilium to regulate tip link tension. (B) In our revised model, different myosin motor populations are responsible for tension generation at the upper tip-link insertion and for mediating slow adaptation. We propose that slow adaptation does not involve the modulation of tip-link tension, requires the function of myosin motors near the MET channels, and involves PIP₂.