Figure 6. The dependence of E-C coupling gain on parameters of the triggering DHPR current.

A, dependence on the single-channel amplitude i_Ca at different extracellular calcium concentrations (given on the labels next to data points). B, dependence on the single-channel amplitude i_Ca at different test potentials (given on the labels next to data points). C, dependence on the fraction of non-inactivated channels, nP_O, at different holding potentials (given on the labels next to data points). Open symbols denote standard conditions (1 mm external Ca²⁺, 0 mV test potential, −60 mV holding potential), to which both axes are normalized. Insets depict the stimulation protocols. Details are given in the Supplemental material.