Astrocytic Ion Dynamics: Implications for Potassium Buffering and Liquid Flow

TL;DR

This paper reviews astrocyte ion dynamics modeling, focusing on spatial potassium buffering and its effects on microscopic and macroscopic brain fluid flow, proposing a multiscale theoretical framework.

Contribution

It introduces the Kirchhoff-Nernst-Planck scheme for modeling astrocytic ion dynamics and links microscopic ion regulation to macroscopic brain fluid flow.

Findings

Kirchhoff-Nernst-Planck scheme effectively models ion transport.

Astrocytic ion dynamics influence microscopic liquid flow.

Potential multiscale link between neural activity and brain fluid movement.

Abstract

We review modeling of astrocyte ion dynamics with a specific focus on the implications of so-called spatial potassium buffering, where excess potassium in the extracellular space (ECS) is transported away to prevent pathological neural spiking. The recently introduced Kirchoff-Nernst-Planck (KNP) scheme for modeling ion dynamics in astrocytes (and brain tissue in general) is outlined and used to study such spatial buffering. We next describe how the ion dynamics of astrocytes may regulate microscopic liquid flow by osmotic effects and how such microscopic flow can be linked to whole-brain macroscopic flow. We thus include the key elements in a putative multiscale theory with astrocytes linking neural activity on a microscopic scale to macroscopic fluid flow.