Optimal Internal Noise for Mammalian Circadian Oscillator

Based on a deterministic mammalian circadian oscillator proposed recently, we have constructed the corresponding mesoscopic stochastic model, and studied the effect of internal noise on the genetic oscillations of such a system. It is found that the stochastic genetic oscillations can show best performance at an optimal internal noise level via a mechanism of internal noise stochastic resonance. Furthermore, it is found that there exists a moderate system size that makes the stochastic model show effective oscillation at more extended region than the deterministic description, which indicates enhanced robustness as the result of internal noise. The potential biological application of such an effect is also discussed.