中文摘要：

通过构建一个耦合细胞体系中细胞内钙振荡的介观随机模型,采用化学Langevin方程研究了耦合细胞体系中内噪声对检测弱刺激的作用.我们发现：对于给定的耦合细胞链的尺度N,存在一个最佳的细胞体积V;并且对于给定的细胞体积V,同样存在一个最佳的耦合细胞链尺度N,在这种情况下细胞内钙振荡的动力学行为最佳,这表明了“尺度共振”或“内噪声随机共振”现象的发生,并且这种现象是不依赖于耦合强度的.生物细胞很可能能够利用内噪声,并通过内噪声随机共振机制来检测弱刺激,从而编码信息用以调节细胞功能.值得一提的是,最佳的细胞体积V总是位于103μm3左右,这与真实的细胞体积很接近.既然生命体系中内噪声是不可避免的,并且体系也经常遇到弱刺激,因此我们的研究结果对于生命体系中的刺激检测过程具有重要的意义.

英文摘要：

By constructing a mesoscopic stochastic model for intracellular calcium oscillations in coupled cell system, we investigated the influence of internal noise on the detection of weak stimulation using the chemical Langevin equation （CLE）. We found that an optimal cell size V existed for a coupled cell chain length N and an optimal value of N existed for a given cell size V. At these values, the collective calcium oscillations showed the best performance, indicating the occurrence of ＂system size resonance （SSR）＂ or ＂internal noise stochastic resonance （INSR）＂. And such a phenomenon was robust to the coupling strength. Living cells may have learned to exploit the internal noise to detect weak stimulation via the mechanism of INSR, and then encode information to specifically regulate distinct cellular functions. It is interesting to note that the optimal cell size is always present at V≈10^3μm3, which is close to the real living cell size in vivo. Since the internal noise in living systems can not be ignored and the systems may often encounter weak stimulations, our findings might have significance for stimulation detecting processes in living systems.