Emergence of log-normal type distributions in avalanche processes in living systems: a network model

Stephano Polizzi , Alain Arneodo , Francisco J. Perez-Reche , Françoise Argoul (1, 2)

1 LOMA - Laboratoire Ondes et Matière d'Aquitaine
2 Phys-ENS - Laboratoire de Physique de l'ENS Lyon

Actin is the major cytoskeletal protein of mammal cells that forms microfilaments organized into higher-order structures by a dynamic assembly-disassembly mechanism with cross-linkers. These networks provide the cells with mechanical support, and allow cells to change their shape, migrate, divide and develop a mechanical communication with their environment. The quick adaptation of these networks upon stretch or compression is important for cell survival in real situations. Using atomic force microscopy to poke living cells with sharp tips, we revealed that they respond to a local and quick shear through a cascade of random and abrupt ruptures of their cytoskeleton, suggesting that they behave as a quasi-rigid random network of intertwined filaments. Surprisingly, the distribution of the strength and the size of these rupture events did not follow power-law statistics but log-normal statistics, suggesting that the mechanics of living cells would not fit into self-organized critical systems.

Mots clés: random network; avalanches; log-normal distributions; power-law; cell plasticity; cytoskeleton ruptures

Domaines: Biophysique [physics.bio-ph]; Cancer; Mécanique statistique [cond-mat.stat-mech]

Stephano Polizzi, Alain Arneodo, Francisco J. Perez-Reche, Françoise Argoul. Emergence of log-normal type distributions in avalanche processes in living systems: a network model. 2020. ⟨hal-03054356⟩