Plasmodium of the Myxomycete Physarum Polycephalum as an Autowave Self-Organizing System

Abstract

The Plasmodium of the acellular slime mold Physarum Polycephalum, when migrating over a substrate, looks like a protoplasmic sheet with a network of channels, which transfer into separate protoplasmic strands or veins in the posterior. Within these channels and strands there is an intensive reciprocating endoplasmic streaming with the period of about 1 min. The streaming is caused by nonstationary gradients of intracellular pressure due to quasiperiodical contractile activity in the relatively stationary ectoplasm. The movement of Plasmodium is driven by the advancing of the endoplasm in each cycle. There is an additional periodicity of about 30 min, connected with the frontal zone extending and the tail region tearing down. As a rule, the two processes are out of phase (Fig.l).