Time delay induces saw-tooth calcium wave and transition in intracellular calcium oscillation

Abstract In view of same time delay τ in active and passive transport processes of intracellular Ca 2 + with additive Gaussian colored noise, using second-order algorithm for stochastic simulation colored noise, intracellular calcium oscillation (ICO) is investigated. By researching the time series and stationary probability distribution (SPD) of intracellular Ca 2 + concentrations, take modest strength and enough long correlation time of additive colored noise, the results indicate that: time delay has a critical point τc ≃ 0.1s of time coherence, as τ > τc, ICO become periodical oscillation, and the waveform converts slowly into square wave from saw-tooth calcium wave as time delay further increases. Additionally, ICO system appears transition from monostable state to bistable state as time delay increases.