FIGURE 9.

Relationship between membrane potential and the open probability (P_open), the single Ca²⁺ channel current (i), and the whole-cell Ca²⁺ current (I; i.e., the product of $N·P_{open}·i$) Note the U-shaped current-voltage relationship for the whole-cell current. The whole-cell slope conductance (G = I/V) between 0 and +50 mV (where the Ca²⁺ channels are maximally active) is ~1 nS (i.e., 50 pA/50 mV). [Modified from Larsson-Nyrén et al. (369).]