The impact of cell connectivity in an astrocytic network on repeatable activation patterns
Darya V. Verveyko, 1
Andrey Yu. Verisokin, 1
Dmitry E. Postnov, 2
Alexey R. Brazhe, 3,4
1 Department of Theoretical Physics, Kursk State University, Kursk, Russia
2 Saratov State National Research University, Saratov, Russia
3 Biological Faculty, Lomonosov Moscow State University, Moscow, Russia
4 Department of Molecular Neurobiology, Institute of Bioorganic Chemistry RAS, Moscow, Russia
Abstract
Astrocyte excitability and signaling are mainly manifested by elevations of intracellular calcium concentration. Downstream of astrocytic calcium signaling are multifaceted effects on the nervous tissue of the brain. Patterns of calcium activity are to a large extent shaped by individual astrocyte morphology and the topology of the astrocytic syncytium. Astrocytic calcium activity is also sensitive to the properties of extracellular space, e.g. extracellular matrix. Intercellular coupling, mediated by gap junctions (GJ) determines large-scale collective dynamics at the astrocyte network level, manifested as calcium waves. We employ a previously proposed two-dimensional model of calcium signaling in the astrocytic syncytium to study the effect of GJ coupling on network activity by varying the connectivity parameter, introduced as the density of GJ contacts. The obtained results indicate that local calcium transients at a single-cell level and repetitive activity patterns change markedly with the increase in the connectivity of astrocytes in the network. On the other hand, the overall level of activity changes insignificantly. In this regard, we hypothesize that astrocyte connectivity defines local patterns of calcium activity, likely affecting local synaptic plasticity and neurovascular coupling. This study was supported by the Russian Science Foundation, grant 21-74-00095.
Speaker
Darya V. Verveyko
Kursk State University
Russia
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