Figure 2. Reversal potentials are shifted by anion substitutions but not by cation substitutions.

A, 50 mm NaCl in the extracellular solution was replaced by 50 mm sodium salt of the anion indicated by each trace. The holding potential was ramped from -70 mV to +10 mV over a period of 1 s, except in the case of SCN⁻, when a ramp from -85 mV to -25 mV was used. B, a similar experiment, varying the cation composition of the extracellular solutions.