Figure 11. Whole-cell current responses evoked by stiff probe deformations of the lateral membrane.

A, digitally captured image of OHC under whole-cell voltage clamp with stiff probe placed across the middle of the cell. B, step mechanical deformation of the lateral membrane evokes a transient gating current and a DC ionic current at the fixed potential of 50 mV. C, relationship of motor gating charge (integrated transient current, Q) and ionic current magnitude (I, difference between steady-state levels before and after membrane stress) with membrane voltage. Motor charge peaks at V_pkcm, whereas I reverses at the potential (−10.5 mV) where total current reverses. D, sinusoidal mechanical stimulation at various potentials produces a corresponding current whose phase reverses at the cell's steady ionic current reversal potential. Extracellular solution was 140 Cl and intracellular was Tris-Hepes + 1 mm Tris-Cl⁻.