On the dynamics of excitation and information processing in F-actin: Automaton model

A filamentous actin molecule is represented as a graph of finite-state machines (F-actin automata). Each node in the graph takes three states—resting, excited and refractory. All nodes update their states simultaneously and by the same rule. Two rules are considered: the threshold rule—a resting node excites if it has at least one excited neighbor, and the narrow excitation interval rule—a resting node excites if it has exactly one excited neighbor. The distributions of transient periods and lengths of limit cycles in F-actin automata are analyzed. Mechanisms of limit cycle emergence are proposed and we speculate on how these can be used to store information in a single actin unit. It is demonstrated that OR, AND-NOT and XOR gates can be implemented by excitation dynamics in F-actin automata. © 2017 Complex Systems Publications, Inc.