G protein-coupled receptor-mediated calcium signaling in astrocytes

TL;DR

This paper develops a biophysical model of GPCR-mediated calcium signaling in astrocytes, exploring how different stimuli influence calcium oscillation patterns, advancing understanding of astrocytic signal transduction.

Contribution

It introduces a novel biophysical modeling approach based on Michaelis-Menten kinetics to describe astrocytic calcium responses to GPCR activation.

Findings

Model effectively describes calcium signal transduction.

Different stimulus shapes and frequencies produce distinct calcium oscillation patterns.

Provides insights into astrocyte signal encoding mechanisms.

Abstract

Astrocytes express a large variety of G~protein-coupled receptors (GPCRs) which mediate the transduction of extracellular signals into intracellular calcium responses. This transduction is provided by a complex network of biochemical reactions which mobilizes a wealth of possible calcium-mobilizing second messenger molecules. Inositol 1,4,5-trisphosphate is probably the best known of these molecules whose enzymes for its production and degradation are nonetheless calcium-dependent. We present a biophysical modeling approach based on the assumption of Michaelis-Menten enzyme kinetics, to effectively describe GPCR-mediated astrocytic calcium signals. Our model is then used to study different mechanisms at play in stimulus encoding by shape and frequency of calcium oscillations in astrocytes.