Effects of Time-Delay on Intracellular Ca²⁺ Concentration Oscillations

Based on SS-model Somogyi R and Stucki J W J. Biol. Chem. 266 (1991) 11068 for the generation of intracellular Ca²⁺ concentration oscillations, we consider a time-delay for the binding kinetics of the Ca²⁺ channel and find a significant phenomenon that the oscillation takes two quite different modes when a parameter of the system across a threshold. One is a quick oscillation mode and the other is a slow oscillation mode. They are different from each other on oscillation frequencies for more than ten times. The change of oscillation form with parameters and its critical behaviour are illustrated by numerical simulation results.