Cytomechanics of oscillatory contractions. Modeling the longitudinal dynamics of Physarum polycephalum protoplasmic strands

摘要: A mathematical model of the longitudinal dynamics an isolated strand Physarum polycephalum plasmodium has been constructed. Its contractile system is considered as a continual viscoelastic medium with passive and active components. The description plasmodial reduced to three first-order differential equations, whose variables are its stress, deformation, intracellular concentration calcium ions. based on hypothesis that there exists feedback loop, which appears because influence stretching rate release ions, in turn control contraction deformation strand. Nonlinear interactions between evoke loss stationary state stability self-excitation mechanochemical autooscillations when external load exceeds some critical value. results numerical solutions empirically determined parameters good agreement available experimental data testify adequacy by apparatus part cellular system. In particular, this well simulates form duration transient processes observed under isotonic isometric conditions immediately after isolation, subsequent excitation activity their activation stretching.