Figure 3. BaCl₂ sensitivity of the TASK-like current.

A, the alkalinization-activated I_SO at −20 mV is inhibited by 1 mm BaCl₂. This effect is partially reversible. B, mean data from recordings as shown in A. Number of cells (n) are given above the bars. *P < 0.05 versus pH_o 8.5 (unpaired t test). C, concentration–response curve for BaCl₂ at pH_o 7.3. I/I_control is the current in the presence of BaCl₂ expressed as a fraction of the current prior to BaCl₂ application. The line is the best fit to the Hill equation using an IC₅₀ of 465 ± 11 μm and Hill coefficient of 2.01 ± 0.08.