FIGURE 1.

Schematic representation of the cochlear hair cells and hair bundles. Two types of hair cells responsible for mechano-electrical transduction and auditory sensing are present in the cochlea. The stair-like W or V-shaped hair bundle appears on the apical plasma membrane of each inner hair cell and outer hair cell, collectively. Each hair bundle contains plenty of stereocilia and a kinocilium near the corner of them, and the kinocilium degenerates after maturation of hair cells, indicating the acquisition of hearing.