FIGURE 4.

Steady-state activity of PC2 channels is greater with slower Ca²⁺ buffering (0.25 mM EGTA compared to 0.25 mM BAPTA). (A) Steady-state activity was measured in one cilium at the voltages shown in 0.25 mM EGTA (left) and 0.25 mM BAPTA (right). (B) In a cilium with just one PC2 channel, the channel also showed higher steady-state activity in 0.25 mM EGTA than in 0.25 mM BAPTA. (C) The effect of slower Ca²⁺ buffering is reversible. A cilium showed higher steady-state activity in 0.25 mM EGTA before and after exposure to 0.25 mM BAPTA. Voltage was maintained at +60 mV. (D) Paired mean steady-state currents for 13 cilia, each tested in both 0.25 mM EGTA and 0.25 mM BAPTA. Voltages were chosen that gave the greatest difference in mean current between 0.25 mM EGTA and 0.25 mM BAPTA and were in all cases +60 or +80 mV *p = 0.010.