AUTHOR=Mariani Benedetta , Nicoletti Giorgio , Bisio Marta , Maschietto Marta , Oboe Roberto , Leparulo Alessandro , Suweis Samir , Vassanelli Stefano TITLE=Neuronal Avalanches Across the Rat Somatosensory Barrel Cortex and the Effect of Single Whisker Stimulation JOURNAL=Frontiers in Systems Neuroscience VOLUME=15 YEAR=2021 URL=https://www.frontiersin.org/journals/systems-neuroscience/articles/10.3389/fnsys.2021.709677 DOI=10.3389/fnsys.2021.709677 ISSN=1662-5137 ABSTRACT=

Since its first experimental signatures, the so called “critical brain hypothesis” has been extensively studied. Yet, its actual foundations remain elusive. According to a widely accepted teleological reasoning, the brain would be poised to a critical state to optimize the mapping of the noisy and ever changing real-world inputs, thus suggesting that primary sensory cortical areas should be critical. We investigated whether a single barrel column of the somatosensory cortex of the anesthetized rat displays a critical behavior. Neuronal avalanches were recorded across all cortical layers in terms of both multi-unit activities and population local field potentials, and their behavior during spontaneous activity compared to the one evoked by a controlled single whisker deflection. By applying a maximum likelihood statistical method based on timeseries undersampling to fit the avalanches distributions, we show that neuronal avalanches are power law distributed for both multi-unit activities and local field potentials during spontaneous activity, with exponents that are spread along a scaling line. Instead, after the tactile stimulus, activity switches to a transient across-layers synchronization mode that appears to dominate the cortical representation of the single sensory input.