Translating from Na to Ca: Na/Ca-exchanger exerts Na-dependent control over astrocytic Ca oscillations

Andrey Yu. Verisokin; Darya V. Verveyko; Varvara V. Kucherenko; Dmitry E. Postnov; Alexey R. Brazhe

doi:10.1140/epjp/s13360-021-01687-3

2022 Impact factor 3.4

EPJ PLUS - Condensed Matter and Complex Systems

Focus Point on Breakthrough Optics- and Complex Systems-based Technologies of Modulation of Drainage and Clearing Functions of the Brain

Eur. Phys. J. Plus (2021) 136: 718
https://doi.org/10.1140/epjp/s13360-021-01687-3

Regular Article

Translating from Na to Ca: Na/Ca-exchanger exerts Na-dependent control over astrocytic Ca oscillations

Andrey Yu. Verisokin¹^a, Darya V. Verveyko¹, Varvara V. Kucherenko², Dmitry E. Postnov³ and Alexey R. Brazhe⁴^,5

¹ Department of Theoretical Physics, Kursk State University, Radishcheva st., 33, 305000, Kursk, Russia
² Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Leninskie Gory, 1/73, Moscow, Russia
³ Saratov State National Research University, Astrakhanskaya st., 83, Saratov, Russia
⁴ Biological Faculty, Lomonosov Moscow State University, Leninskie Gory, 1/24, Moscow, Russia
⁵ Department of Molecular Neurobiology, Institute of Bioorganic Chemistry RAS, Miklukho-Maklay st., 16/10, Moscow, Russia

^a ffalconn@mail.ru

Received: 31 December 2020
Accepted: 21 June 2021
Published online: 5 July 2021

Abstract

Recently accumulated evidences suggest that astrocyte signaling is in touch link with extracellular volume regulation and interstitial fluid drainage from the brain. Classical understanding of astrocyte activity is based on IP-dependent calcium exchange with intracellular stores. Recent evidence shifts focus to calcium entry from extracellular space via multiple mechanisms and widens it to taking other ions into account. It has been hypothesized that Na/Ca-exchanger can translate activity-dependent Na transients into modulation of Ca dynamics. We combine a model of IP-based Ca dynamics with a model of Ca flow through Na/Ca-exchanger to provide theoretical insights into the possible effects of such modulation. We find that the exchanger can provide for bidirectional Na-dependent modulation of the sensitivity to extracellular glutamate, oscillation amplitude and frequency modulation, as well as extending the available set of dynamical regimes. The extent of the emergent Na sensitivity is predicted to be scaled by a morphology-dependent balance between the maximal flow through the exchanger and the rate of entry from intracellular stores.