Anti-phase calcium oscillations in astrocytes via inositol (1, 4, 5)-trisphosphate regeneration

Observations in cultured mouse astrocytes suggest anti-phase synchronization of cytosolic calcium concentrations in nearest neighbor cells that are coupled through gap junctions. A mathematical model is used to investigate physiologic conditions under which diffusion of the second messenger inositol (1, 4, 5)-trisphosphate (IP3) through gap junctions can facilitate synchronized anti-phase Ca2+ oscillations. Our model predicts anti-phase oscillations in both cytosolic calcium and IP3 concentrations if (a) the gap junction permeability is within a window of values and (b) IP3 is regenerated in the astrocytes via, e.g. phospholipase Cδ. This result sheds new light on the current dispute on the mechanism of intercellular calcium signaling. It provides indirect evidence for a partially regenerative mechanism as the model excludes anti-phase synchrony in the absence of IP3 regeneration.