论文标题
与较小的信号隔室的2D PDE-ode模型的同步和振荡动力学
Synchrony and Oscillatory Dynamics for a 2-D PDE-ODE Model of Diffusion-Sensing with Small Signaling Compartments
论文作者
论文摘要
我们分析了一类细胞络合耦合的PDE模型,这些模型是由群体和微生物系统中的扩散传感现象激励的,这些模型表征了具有渗透性边界的局部空间分离的动态活性信号隔室之间的通信。每个细胞以恒定的速率分泌一个信号化学物质,并从整个细胞集合中接收大量化学物质的反馈。这种激活单元内信号通路的全局反馈会根据外部环境修饰细胞内动力学。细胞分泌和全局反馈受整个细胞膜的渗透性参数调节。对于每个细胞中的任意反应 - 金属学,在小细胞半径的极限中使用了匹配的渐近膨胀方法来构建PDE-ODE模型的稳态溶液,并得出一个全球耦合的非线性矩阵特征值问题(GCEP),以表征稳态稳定性的线性稳定性的特征。在大量扩散率的极限中,对PDE模型模型的渐近分析导致限制ode系统,用于大体区域中浓度的空间平均值,该系统与细胞内的细胞内动力学耦合。对于Sel'kov反应 - 金属学说明了线性稳定性理论和ODE动力学的结果,其中选择了动力学参数,以便在与散装培养基中取消偶联时每个细胞都会静止。对于细胞的各种特定空间构型,线性稳定性理论用于在参数空间中构造相图,以表征,其中可以通过HOPF分叉发生细胞内振荡的开关样出现。
We analyze a class of cell-bulk coupled PDE-ODE models, motivated by quorum and diffusion sensing phenomena in microbial systems, that characterize communication between localized spatially segregated dynamically active signaling compartments that have a permeable boundary. Each cell secretes a signaling chemical into the bulk region at a constant rate and receives a feedback of the bulk chemical from the entire collection of cells. This global feedback, which activates signaling pathways within the cells, modifies the intracellular dynamics according to the external environment. The cell secretion and global feedback are regulated by permeability parameters across the cell membrane. For arbitrary reaction-kinetics within each cell, the method of matched asymptotic expansions is used in the limit of small cell radius to construct steady-state solutions of the PDE-ODE model, and to derive a globally coupled nonlinear matrix eigenvalue problem (GCEP) that characterizes the linear stability properties of the steady-states. In the limit of large bulk diffusivity an asymptotic analysis of the PDE-ODE model leads to a limiting ODE system for the spatial average of the concentration in the bulk region that is coupled to the intracellular dynamics within the cells. Results from the linear stability theory and ODE dynamics are illustrated for Sel'kov reaction-kinetics, where the kinetic parameters are chosen so that each cell is quiescent when uncoupled from the bulk medium. For various specific spatial configurations of cells, the linear stability theory is used to construct phase diagrams in parameter space characterizing where a switch-like emergence of intracellular oscillations can occur through a Hopf bifurcation.