Synaptic plasticity and neuronal refractory time cause scaling behaviour of neuronal avalanches

TL;DR

This paper investigates how synaptic plasticity and neuronal refractory time influence the scaling behavior of neuronal avalanches, revealing mechanisms that lead to mean field-like activity patterns in neuronal networks.

Contribution

It demonstrates that refractory time and Hebbian plasticity together shape avalanche dynamics and network topology, explaining the origin of observed scaling laws.

Findings

Refractory time induces directed avalanche propagation.

Hebbian plasticity transforms network topology into a branched structure.

Scaling behavior persists across different network topologies.

Abstract

Neuronal avalanches measured in vitro and in vivo in different cortical networks consistently exhibit power law behaviour for the size and duration distributions with exponents typical for a mean field self-organized branching process. These exponents are also recovered in neuronal network simulations implementing various neuronal dynamics on different network topologies. They can therefore be considered a very robust feature of spontaneous neuronal activity. Interestingly, this scaling behaviour is also observed on regular lattices in finite dimensions, which raises the question about the origin of the mean field behaviour observed experimentally. In this study we provide an answer to this open question by investigating the effect of activity dependent plasticity in combination with the neuronal refractory time in a neuronal network. Results show that the refractory time hinders backward avalanches forcing a directed propagation. Hebbian plastic adaptation plays the role of sculpting these directed avalanche patterns into the topology of the network slowly changing it into a branched structure where loops are marginal.