Figure 4.

The ΔpH dependence of gating ensures that, in most species, H_V1 channels open only when doing so will result in acid extrusion. Each symbol or letter indicates a different cell type or species, defined in [68]. The blue line shows the relationship that results in H⁺ channels in almost all cells opening at their threshold voltage, V_threshold, at voltages positive to the Nernst potential (or the experimentally measured reversal potential, V_rev), shown as the red dashed line. At more positive voltages (above the blue line) more channels would open, extruding more protons. Reprinted with permission from DeCoursey & Hosler [69], with modification (Copyright © 2014 Rockefeller University Press).