FIG. 6.

Prestin transduction endows immature OHCs with nonlinear capacitance. Representative examples of the whole-cell voltage clamp technique in transduced immature preparations. A The three rows of OHC V-shaped stereocilia can be noted in the differential interference contrast image. The patch pipette was in contact with an OHC within the third row. B The fluorescence image demonstrates GFP expression within some of the OHCs. C The merged image demonstrates that the patch pipette was in contact with a GFP-positive OHC. After subtracting out the linear membrane capacitance, GFP-positive wild-type (D) and prestin-null (E) OHCs had an obvious voltage-dependent nonlinear capacitance, in contrast to GFP-negative and control OHCs. The solid black lines are Boltzmann fits to the data. Fit parameters: DV_pkcm = −53.0 mV, α = 25.7 mV, Q_max = 446.5 fC and EV_pkcm = −43.0 mV, α = 27.7 mV, Q_max = 382.0 fC in (E). Scale bar: 40 μm.