Figure 2.

Reversal potentials of the inward currents. Mean values (± se) of E_rev and E_L, the reversal potentials of the time-dependent and the instantaneous currents, versus K⁺_O, K⁺ activity in the bath. K⁺_O was calculated from the external K⁺ concentrations using activity coefficients from (Robinson and Stokes, 1965). When not seen, the error bars are smaller than the symbols. Data are from four extensors (E) at [K⁺]_O of 5 mm, five extensors, and eight flexors (F) at 40 mm and from 10 extensors and 11 flexors at 200 mm. The dotted line represents the calculated E_K, the Nernst potential of K⁺ (Eq. 2). Solutions were distributed as follows: bath: 5 mm K⁺ (solution a)/pipette: (f); bath: 40 mm K⁺ (solution b)/pipette: (f) (four extensors and six flexors), or (g) (one flexor), or (h) (one extensor and one flexor); bath: 200 mm K⁺ solution c)/pipette: (f).