Figure 5. K⁺-dependent stability of G_K.

A, left panel, control I_K evoked by a 0 mV/30 ms pulse in 40K_o/Na_i solutions (see Methods). Right panel, I_K left after the immersion of the cell in, 0 K⁺ solutions (Na_o/Na_i) for 5 min, with the channels maintained closed at the HP of −80 mV during the exposure to 0 K⁺ (not shown, indicated by the arrow). B, comparison of the I_K remaining either after 5 min exposure to 0 K⁺, as in A, or after a 25 min recording with K⁺ present on only one side of the membrane, as indicated.