Effects of the dynamics of noise-induced calcium signals in a biophysical model of the astrocytic process

The purpose of this work is to study the effects of spatio-temporal dynamics of spontaneous calcium signaling in the morphological structure of an astrocyte at the subcellular level using biophysical mathematical modeling methods. Methods. This work proposes a biophysical multicompartmental model of noise-induced calcium dynamics in the astrocytic process. The model describes the process of generation of spontaneous Ca2+ signals induced by the stochastic activation of voltage-dependent Ca2+ channels on the plasma membrane of the astrocyte. The model allows us to study the dynamics of the propagation of spontaneous local Ca2+ signals and the mechanisms of formation of spatial Ca2+ patterns in the astrocytic process. Results. The developed model enables studying the influence of morphology and intracellular biophysical mechanisms on the characteristics of spontaneous noise-induced Ca2+ signaling in the astrocytic process. The parameter ranges at which the model qualitatively reproduces the spontaneous Ca2+ activity at the subcellular level observed in experimental studies have been specified. The characteristics of noise-induced Ca2+ patterns propagating along the process were investigated, depending on the internal structure of the process, its geometry, and the steady state concentration of inositol 1,4,5-triphosphate molecules.