Figure 5. Gradients in tip-link tension at rest.

Offset $\mathrm{\Delta }{X}_{\mathrm{R}}$ in the resting position of a hair bundle resulting from tension release in the tip links (A), tip-link tension $T_{\mathrm{R}}={\mathrm{{\rm K}}}_{\mathrm{S}\mathrm{P}}\mathrm{}\mathrm{\Delta }{X}_{\mathrm{R}}$ in the hair bundle (B) and tension ${\displaystyle t_{\mathrm{R}}=T_{\mathrm{R}}/\left(\gamma N_{\mathrm{T}\mathrm{L}}\right)}$ along the oblique axis of a single tip link (C) as a function of the characteristic frequency (CF) for inner (white disks) and outer (black disks) hair cells. The hair-bundle tension $T_{\mathrm{R}}$ (B) was calculated as the product of the stereociliary-pivot stiffness ${\mathrm{{\rm K}}}_{\mathrm{S}\mathrm{P}}$ shown in Figure 3 and the data shown in (A); this tension is estimated along the bundle’s horizontal axis of mirror symmetry. The single tip-link tension $t_{\mathrm{R}}$ was then deduced from the projection factor $\gamma$ and the average number ${\displaystyle N_{\mathrm{T}\mathrm{L}}}$ of intact tip links in a hair bundle (Figure 3—figure supplement 3). Each data point in (A) is the mean ± SEM with the number of cells indicated between brackets; in (B–C), mean values and SEMs were calculated as described in the Materials and methods.