Fig. 3.

Reversal potential of the H⁺-induced current. A, B, Reversal potential measurements in NMDG Ringer’s solutions at pH 5.5 and 6.5, respectively. The membrane potential was held at −40 mV and jumped for 6 sec to the test potentials noted adjacent to each current trace. Thebars above current traces indicate the period when desipramine (10 μm) was applied. C, Reversal potentials measured by experiments shown above were plotted as a function of pH. Vertical lines indicate the SD (n = 3). Dashed line is the least-square fit, with a slope of −55 mV/pH U.