Computational Astrocyence: Astrocytes encode inhibitory activity into the frequency and spatial extent of their calcium elevations

Abstract

Deciphering the complex interactions between neurotransmission and astrocytic Ca 2+ elevations is a target promising a comprehensive understanding of brain function. While the astrocytic response to excitatory synaptic activity has been extensively studied, how inhibitory activity results to intracellular Ca 2+ waves remains elusive. In this study, we developed a compartmental astrocytic model that exhibits distinct levels of responsiveness to inhibitory activity. Our model suggested that the astrocytic coverage of inhibitory terminals defines the spatial and temporal scale of their Ca 2+ elevations. Understanding the interplay between the synaptic pathways and the astrocytic responses will help us identify how astrocytes work independently and cooperatively with neurons, in health and disease.

Astroglial Isopotentiality and Calcium-Associated Biomagnetic Field Effects on Cortical Neuronal Coupling

“…Moreover, small changes in Ca 2+ buffering may influence the spread of regenerative glial Ca 2+ waves, being consistent with the slow Ca 2+ transients experimentally reported [72]. In agreement, some models of astrocyte behavior have shown that astroglial Ca 2+ waves may induce neuronal synchronization and spatial clustering of synaptic plasticity, showing that the number of inhibitory terminals that one astrocyte ensheathes is critical for the spatial extent and temporal duration of astrocytic Ca 2+ transients [73]. However, when the number of active synapses increases into an astrocytic domain, there were simultaneous Ca 2+ elevations in multiple microdomains that together were able to trigger the Ca 2+ elevations in the thicker astrocytic branches, which were spatially expanded and prolonged in time having a lower frequency [73].…”