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DY: Fachverband Dynamik und Statistische Physik

DY 28: Networks: From Topology to Dynamics I (joint session SOE/DY)

DY 28.4: Vortrag

Mittwoch, 20. März 2024, 15:45–16:00, TC 006

Neuronal avalanches in weakly coupled FitzHugh-Nagumo oscillators — Max Contreras¹, Everton Medeiros², Igor Franović³, and •Philipp Hövel⁴ — ¹Technische Universität Berlin, Germany — ²Carl von Ossietzky University Oldenburg, Germany — ³University of Belgrade, Serbia — ⁴Saarland University, Germany

The activity in the brain cortex remarkably shows a simultaneous presence of robust collective oscillations and neuronal avalanches, where intermittent bursts of pseudo-synchronous spiking are interspersed with long periods of quiescence. The mechanisms allowing for such coexistence are still a matter of an intensive debate. Here, we demonstrate that avalanche activity patterns can emerge in a rather simple model of an array of diffusively coupled neural oscillators with multiple timescale local dynamics in the vicinity of a canard transition. The avalanches coexist with the fully synchronous state where the units perform relaxation oscillations. We show that the mechanism behind the avalanches is based on an inhibitory effect of interactions, which may quench the spiking of units due to an interplay with the maximal canard. The avalanche activity bears certain heralds of criticality, including scale-invariant distributions of event sizes. Furthermore, the system shows increased sensitivity to perturbations, manifested as critical slowing down and reduced resilience.

Reference: Max Contreras, Everton S. Medeiros, Anna Zakharova, Philipp Hövel, and Igor Franović: Scale-free avalanches in arrays of FitzHugh-Nagumo oscillators, Chaos 33, 093106 (2023).

Keywords: avalanches; FitzHugh–Nagumo model; neuronal dynamics; weak coupling