The influence of subthreshold periodic stimuli on temporal-spatial resonance of ［Ca2+］ in a stochastic coupled hepatocytes system is studied. When the frequency of stimuli is close to that of the determinate coupled system before the Hopf bifurcation, the eruption rate of ［Ca2+］ is enhanced greatly in the stochastic system. By computing the autocorrelation function of the eruption rate, it is found that the temporal resonance of ［Ca2+］ becomes more ordered by the subthreshold stimuli. Furthermore, for a given coupling strength between cells, there is an optimal noise level to make the ［Ca2+］ resonance reach maximum, and the optimal noise level also increases with the coupling strength increasing. Though the action of subthreshold stimuli promotes the temporal resonance of the system, it strengthens the sensibility to noise and then depresses the spatial ordered calcium waves induced by medium-strength noise only, as shown by the analysis by the spatial Fourier transform and its structure function.
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