Figure 5. Ion selectivity favors potassium over cesium.
Representative current traces at the voltages listed are shown with symmetrical K+ (A) and Cs+ (B) as the predominate charge carrying ions. (C) Average (± SE) current-voltage relationships were constructed for both KCl and CsCl experiments. Traces were obtained at test potentials between −100 mV and 100 mV in 10 mV increments. Data were fitted with linear functions and conductances were calculated from the slopes as described in Methods. Reversal potentials were unaltered. However, a profound decrease in the slope conductance from K+ (745 ± 18 pS) to Cs+ (454 ± 17 pS) as charge carrier was evident. Traces are representative examples of at least 4 other patches.