Fig. 1.

Hair bundle development and quantification of stereocilia number and diameters. a SEM image of a relatively mature inner hair cell (IHC) bundle at the middle of the cochlea in a control mouse at postnatal day 10 (P10). Note the well-organized three rows of stereocilia that form a staircase. Examples of diameter measurements are illustrated by lines of different colors in the first (red), second (cyan), and third (green) rows of stereocilia. b, c “Top view” of the control IHC (b) and an OHC (c) immature stereocilia bundles at P0 in the same mid-cochlear location with all nascent stereocilia (stereocilia-like projections) marked. Identifiable stereocilia rows are indicated with markers of different colors. Scale bars 1 μm