V_L diagrams show the contribution of major currents during the interburst period at 8 mM [G] (A) and 16 mM [G] (B). (Top) Time-dependent changes in V_L (red) and V_m (black). The V_m trace is overlapped by V_L. (Middle) Time-dependent changes in the contribution (c) of individual currents indicated with different colors. A positive c indicates that the time-dependent change in the corresponding current contributes to depolarization (in mV s⁻¹), and vice versa. The contribution of I_CaV was divided into c of d_CaV and c of f_us. The rest for I_CaV was negligibly small (not depicted). (Bottom) Separation of the contribution of I_NaK into [ATP]- and [MgADP]-dependent components (dark yellow) and [Na⁺]_i-dependent component (gray). Effects of other factors on I_NaK, such as time-dependent changes in [K⁺]_i or V_m, were negligibly small (not depicted). The time scales refer to those for the gray bars in Fig. 4 (A and B).