Understanding complex oscillations in intracellular calcium dynamics

Change in the concentration of free intracellular calcium is a crucial control mechanism in many cells, with oscillations of calcium concentration being thought to play an important role in secretion, muscle contraction, cardiac electrophysiology and many other aspects of cell physiology. A great deal of experimental and modelling work has been done to investigate intracellular calcium dynamics in a large number of different physiological settings, with a main aim being to identify the mechanisms underlying calcium oscillations.

Complex calcium oscillations have been observed in experiments on, and a recent model of, hepatocytes (liver cells). The presence of multiple timescales in the data and the model suggests that mathematical methods that exploit the timescale separation, such as geometric singular perturbation theory (GSPT), could be useful. I will talk about some general principles for the way timescales are important in calcium models and about some of the impediments there are to rigorous application of GSPT to the hepatocyte model of interest.