Emergence of behaviour in a self-organized living matter network.

Philipp Fleig,Mirna Kramar,Karen Alim,Michael Wilczek

doi:10.7554/elife.62863

Abstract

What is the origin of behaviour? Although typically associated with a nervous system, simple organisms also show complex behaviours. Among them, the slime mold Physarum polycephalum, a giant single cell, is ideally suited to study emergence of behaviour. Here, we show how locomotion and morphological adaptation behaviour emerge from self-organized patterns of rhythmic contractions of the actomyosin lining of the tubes making up the network-shaped organism. We quantify the spatio-temporal contraction dynamics by decomposing experimentally recorded contraction patterns into spatial contraction modes. Notably, we find a continuous spectrum of modes, as opposed to a few dominant modes. Our data suggests that the continuous spectrum of modes allows for dynamic transitions between a plethora of specific behaviours with transitions marked by highly irregular contraction states. By mapping specific behaviours to states of active contractions, we provide the basis to understand behaviour's complexity as a function of biomechanical dynamics.

Highlights

Survival in changing environments requires from organisms the ability to switch between diverse behaviors [1, 2]
We here investigate the characteristics of mode dynamics that result from a continuous spectrum and how these shape the organism’s behavior
While our observations suggest that prolonged regular dynamics dominated by a few or even a single mode are associated with specific behavior like locomotion, the many-mode states seem to serve as transition states between them

Summary

Introduction

Survival in changing environments requires from organisms the ability to switch between diverse behaviors [1, 2]. By perturbing the network with an attractive stimulus, we show that the resulting locomotion response is coupled to a selective activation of regular contraction patterns Guided by these observations, we design an experiment on a P. polycephalum specimen reduced in morphological complexity to a single tube. We design an experiment on a P. polycephalum specimen reduced in morphological complexity to a single tube This allows us to quantify the causal relation between locomotion behavior, cytoplasmic flow rate and varying types of contraction patterns, revealing the central role of dynamical variability to generate different behaviors

Methods

Results

Conclusion