Fig 6. Relative Na⁺ fluxes.

The relative contributions of selected Na⁺ flux pathways to [Na⁺]_i homeostasis. These relative flux values were calculated during the last AP (number 700) for each of the four conditions described in Figs 2 and 4. Simulations were conducted at 1 Hz: (A) steady-state control conditions (current clamp), (B) a 5-fold increase in I_Na-L (current clamp), (C) short AP clamp and a 5-fold increase in I_Na-L (short AP + 5×I_NaL), and (D) long AP clamp with normal I_Na-L (long AP + 1×I_NaL).