Clusters of IP3 receptor channels in the membranes of the endoplasmic reticulum (ER) of many non-excitable cells release calcium ions in a cooperative manner giving rise to dynamical patterns such as Ca2+ puffs, waves and oscillations that occur on multiple spatial and temporal scales. We introduce a minimal yet descriptive reaction- diffusion model of IP3 receptors for a saturating concentration of IP3 using a principled reduction of a detailed Markov chain description of individual channels. A dynamical systems analysis reveals the possibility of excitable, bistable and oscillatory dynamics of this model that correspond to three types of observed patterns of calcium releases -- puffs, waves and spikes respectively. We explain the emergence of these patterns via a bifurcation analysis of a coupled two-cluster model, compute the phase diagram and quantify the speed of the waves and period of oscillations in terms of system parameters.
|Number of pages||1|
|Publication status||Published - 25 Sep 2017|
|Event||EMBO workshop, LabEx INFORM: Dynamics of Living Systems - Cargèse, France|
Duration: 25 Sep 2017 → 29 Sep 2019
|Workshop||EMBO workshop, LabEx INFORM: Dynamics of Living Systems|
|Period||25/09/17 → 29/09/19|