Collective Information and Communication in Morphologically Distinct Astrocytes

Abstract

AbstractThe activity patterns in astrocytes are of considerable importance, given the recent finding that individual astrocytes actively integrate information from neuronal groups. This work analyzes collective information capacity and information flow ofin vitroastrocyte networks themselves. We investigate group Ca2+dynamics in several astrocyte phenotypes – polygonal, stellate, and reactive – which represent distinct cytoskeletal architectures with differences in cell-cell coupling that may affect information flow within astrocyte networks. All morphologies are present in the brain to varying degrees at different physiological states. To gain insights into the ability of astrocyte networks to respond to changes in the extracellular environment, we probe the networks with perturbations affecting their activity levels (ATP) and their cytoskeletal dynamics (Latrunculin B). Correlation analysis yields a uniform speed of communication, consistent with the speed of Ca2+waves, confirming that Ca2+serves as the primary mode of information exchange independent of morphology and extracellular environment. To obtain a quantitative metric of group communication, we measure the entropy and partitioned (time-dependent) entropy of the Ca2+dynamics. We find that communication metrics vary depending on astrocyte morphological phenotype and environmental perturbations, indicating that astrocytes’ roles in communication may shift with development and microenvironment.