FIGURE 3.

Alkylsulfonic anions shift prestin's V_op over a wide range (from depolarizing to hyperpolarizing) of membrane potentials as a function of hydrocarbon chain length. (A) C_v-V curves (thick line) and their fits (thin line) obtained from the same OHC perfused with Na-Mal_(i) intracellular solution while control anions and sulfonic anions with increasing hydrocarbon chain length were applied extracellularly in the order (of solutions) (1) Na-Mal_(o), (2) Na-MeSO_3(o), (3), Na-EtSO_3(o), (4), Na-PrSO_3(o), (5), Na-PnSO_3(o), (6), Na-SO_4(o), and (7), Na-Cl_(o). Circles and horizontal error bars above traces represent mean ± SD for prestin V_pkCm values obtained in 10 cells. (B and C) Columns and vertical error bars represent statistics (mean ± SD) for Q_max (B) and z (C) values obtained from the same fits that were used to obtain V_pkCm parameters in A. Columns for the appropriate anions are placed in the order and relative position of their V_pkCm values on the scale of membrane potentials.