Spatial mapping reveals multi-step pattern of wound healing in Physarum polycephalum

TL;DR

This study maps the multi-step wound healing process in Physarum polycephalum, revealing coordinated contraction patterns and the surprising role of severing as an attractive stimulus for network repair.

Contribution

It uncovers the spatial and temporal contraction patterns during Physarum's wound healing, highlighting a multi-phase process and the stimulus-like effect of severing.

Findings

Wound healing involves alternating activity and stalling phases.

Severing acts as an attractive stimulus promoting healing.

Contraction cessation may reveal biochemical mechanisms.

Abstract

Wounding is a severe impairment of function, especially for an exposed organism like the network-forming true slime mould Physarum polycephalum. The tubular network making up the organism's body plan is entirely interconnected and shares a common cytoplasm. Oscillatory contractions of the enclosing tube walls drive the shuttle streaming of the cytoplasm. Cytoplasmic flows underlie the reorganization of the network for example by movement toward attractive stimuli or away from repellants. Here, we follow the reorganization of Physarum polycephalum networks after severe wounding. Spatial mapping of the contraction changes in response to wounding reveal a multi-step pattern. Phases of increased activity alternate with cessation of contractions and stalling of flows, giving rise to coordinated transport and growth at the severing site. Overall, severing surprisingly acts like an attractive stimulus enabling healing of severed tubes. The reproducible cessation of contractions arising during this wound-healing response may open up new venues to investigate the biochemical wiring underlying Physarum polycephalum's complex behaviours.