Abstract: In a model of intercellular calcium ion system oscillations, internal stochastic resonance(ISR) is investigated under the modulation of two parameters, viz., degree of extracellular stimulation β and leak rate k_f. When either β or k_f is subjected to a noise, ISR can occur. When noise is added to the two parameters simultaneously, internal stochastic bi-resonance(ISBR) occurs. The distance to the bifurcation point is found to be able to enhance or suppress the ISBR, and to affect the number of peaks of ISR.

Key words: Internal stochastic resonance, Ca²⁺ oscillations, Control parameter