FIGURE 3.

Changing adaptation rate by influencing Ca²⁺ influx through transduction channels. (A) Adaptation slowed by reducing external Ca²⁺ concentration. Transduction currents, evoked by a family of 6-ms force steps and recorded at −80 mV, showed robust adaptation in 4 mM Ca²⁺ external solution (top), which was slowed by reducing the external Ca²⁺ concentration to 0.1 mM (middle). The corresponding bundle deflection in 4 mM Ca²⁺ is shown (bottom). Force steps were from −30 to +65 pN. (B) Adaptation slowed by depolarizing the cell. Holding potential was changed to −120 mV (top) or to +40 mV (middle) 4 ms before the force steps. Adaptation of the transduction current was largely abolished at +40 mV. In addition, channels appeared to open more slowly. The bundle deflection at −120 mV is shown (bottom).