Figure 3.

Na⁺_i dependence of I_H. (A) Recording from a patch at V_h = −80 mV in the presence of different [Na⁺_i]. (B) MgATP-activated I-V curves at the indicated [Na⁺_i], normalized to I_H at −140 mV, 20 mM Na⁺_i. (C) I_H at −140 mV as a function of [Na⁺_i]. The solid line represents a fit to the Hill function (Eq. 1), with parameters in the text. The dotted line represents a fit of the [Na⁺_i]-dependence of charge movement to Eq. 1 (from Ref. (24)). Data in (B) and (C) are means ± SEM from four patches. To see this figure in color, go online.