Cytoplasmic Ca²⁺ Dynamics under the Interplay between the Different IP₃R Gating Models and the Plasma Membrane Ca²⁺ Influx

The cytoplasmic Ca²⁺ oscillations are investigated under the effect of CRAC channels in non-excitable cells (especially in T cells). The oscillatory Ca²⁺ signals can be modulated as the amplitude-, frequency- and mixed amplitude-frequency modulation modes dependent on the different IP₃R gating models. Bifurcation analyses show that Ca²⁺ signals in the single positive feedback loop model is a mixed modulation mode. In contrast, Ca²⁺ signals in the Mak-McBride-Foskett model demonstrates approximately the frequency modulation mode only with slight amplitude shifts.