AUTHOR=Cresswell-Clay Evan , Crock Nathan , Tabak Joël , Erlebacher Gordon 

TITLE=A Compartmental Model to Investigate Local and Global Ca2+ Dynamics in Astrocytes

JOURNAL=Frontiers in Computational Neuroscience

VOLUME=Volume 12 - 2018

YEAR=2018

URL=https://www.frontiersin.org/journals/computational-neuroscience/articles/10.3389/fncom.2018.00094

DOI=10.3389/fncom.2018.00094

ISSN=1662-5188

ABSTRACT=Intracellular \ca dynamics in astrocytes can be triggered by neuronal activity and in turn regulate a variety of downstream processes that modulate neuronal function. In this fashion, astrocytic \ca signaling is regarded as a processor of neural network activity by means of complex spatial and temporal \ca dynamics. Accordingly, a key step is to understand how different patterns of neural activity translate into spatiotemporal dynamics of intracellular \ca in astrocytes.  Here, we introduce a minimal compartmental model for astrocytes that can qualitatively reproduce essential hierarchical features of spatiotemporal \ca dynamics in astrocytes. We find that the rate of neuronal firing determines the rate of \ca spikes in single individual processes as well as in the soma of the cell, while correlations of incoming neuronal activity are important in determining the rate of "global" \ca spikes that can engulf soma and the majority of processes. Significantly, our model predicts that whether the endoplasmic reticulum is shared between soma and processes or not determines the relationship between the firing rate of somatic \ca events and the rate of neural network activity. Together these results provide intuition about how neural activity in combination with inherent cellular properties shapes spatiotemporal astrocytic \ca dynamics, and provide experimentally testable predictions.