Fig. 3.

Steady-state responses of the minimal whole cell model of local and global Ca²⁺ signaling as a function of the Ca²⁺ activation rate constant (k_co) in the single channel ryanodine receptor (RyR) model (Eq. 1). A: bulk SR [Ca²⁺] (c_sr, Eq. 18). B: fraction of open channels in the whole cell model (f_O, solid line) as well as single channel RyR open probability (P_O, Eq. 25, dashed line). C: spark frequency. D: mean spark duration. Solid circles indicate standard parameter values; open circles indicate the reduction in k_co corresponding to the simulated addition of tetracaine.