FIGURE 8.
Effects of changing pHi on the recovery rate from desensitization of ASIC1a and ASIC2a channels. A, left, representative traces showing the time-dependent recovery of ASIC1a current from desensitization in the absence and presence of 1 mm quinine. Right, peak current amplitude activated by the second acid application was normalized to the amplitude of the first current in each pair and plotted against the time interval before and after quinine application. The solid lines are single exponential fits to the data points. Intracellular alkalization by quinine significantly accelerates the time constants of recovery (control: 31 ± 16 s, n = 5; quinine: 6 ± 2 s, n = 5, t(8) = 3.3, unpaired t test, p < 0.01). B, representative current traces (left) and summary data (right) showing the unchanged recovery rate from desensitization of the ASIC2a channel by intracellular alkalizing agent quinine (control: 1.3 ± 0.2 s, n = 8; quinine: 2.0 ± 0.2 s, n = 6, t(12) = 0.9, unpaired t test, p > 0.05). Right, solid lines are double exponential fits to the data points. Note that x axis is log scale.