THE PHYSICAL BASES OF CELL-MOVEMENT - THE MECHANISMS OF AMEBOID MOTILITY SELF-ORGANIZATION

Structure formation and autowave processes in active media far from equilibrium are the subject of special division of the theory of nonlinear dynamic systems. In present review the protoplasm of amoeboid cells is considered as active medium, in which gel-like structures continuously appear and disappear as a result of assembly and disassembly of actomyosin network. The local parts of these structures can spontaneously contract and relax, causing rather complex circular- or shuttle-type hows of sol-like protoplasm. We consider the mathematical models of movements, wherein the appearing dissipative structure and the autowave processes cause each another. The main quantitative features of the protoplasm dynamics are shown to be explained by postulating the existence of positive feedback, between the local deformations and the free calcium level controlling the network contraction. The potentialities of different physical methods in order to determine the values of parameters used in the mathematical models is discussed.