Figure 5

Contribution of \(I_{\mathrm{CaT}}\) to \(\text{F} \to \text{SD}\) transitions triggered by hyperpolarizing current pulses. A. Response of the standard model to a 300 ms hyperpolarizing pulse (\(-3.9~\mu \mbox{Acm}^{-2}\)) before (A₁) and after (A₂) blocking \(I_{\mathrm{CaT}}\). B. Evolution of the bifurcation diagram of a variant model where the inactivation variable \(h_{\mathrm{CaT}}\) is considered an adjustable parameter. C. Minimum amplitude of a hyperpolarizing current pulse capable to trigger the \(\text{F} \to \text{SD}\) transition as a function of the pulse duration