Deterministic and stochastic models of intracellular Ca2 waves

Intracellular Ca 2+ dynamics allows for the observation of wave formation from elemental release events to the global phenomenon. It shows propagating waves with deterministic features and at the same time probabilistic behaviour like variable periods. Formulation and analysis of deterministic wave models sheds new light on experimental observations and contributes to the theory of nonlinear propagating waves by exhibiting new instabilities. That is demonstrated with the example of Ca 2+ waves with energized mitochondria. Stochastic models can describe spatio-temporal structures from localized puffs to propagating waves. They explain the origin of long timescales in Xenopus oocytes and wave generation. The implications of the results of both approaches for the theory of intracellular Ca 2+ dynamics is discussed.