Local and collective IP3-mediated calcium dynamics in astrocyte network

Abstract

Astrocytes are branched glial cells that provides the excitation of neurons as well as their synaptic coupling. Each astrocyte cell is connected with a huge number of neural synapses. The dynamics of cytosolic calcium underlie the transmission of signals from astrocytes in the brain. We numerically analyze the proposed previously spatially-detailed model of calcium activity in astrocytes, which complies with the recent understanding of two different mechanisms of calcium dynamics: (i) excitable IP3-mediated exchange with ER in astrocyte soma and thick branches; (ii) exchange with the extracellular space in leaflets and neuropil. We study the influence of the shape of the soma with thick branches on the calcium dynamics of the model cell. Depending on the level of synaptic activity and the rate of calcium diffusion, various activity patterns are observed: from localized spontaneous transients to regular calcium oscillations. The probability of propagation and velocity of calcium oscillations between individual cells is determined by (i) the shape of the soma region and thick branches of each cell and (ii) the total perimeter of the associated cells area. The obtained results suggest that local features of astrocyte morphology can determine the properties of its calcium activity and assign its role in the activity of the entire astrocytic syncytium.

Speaker

Darya V. Verveyko
Kursk State University
Russia

Discussion

Ask question