Frequency of elemental events of intracellular Ca2 dynamics

The dynamics of intracellular Ca2 is driven by random events called Ca2 puffs, in which Ca2 is liberated from intracellular stores. We show that the emergence of Ca2 puffs can be mapped to an escape process. The mean first passage times that correspond to the stochastic fraction of puff periods are computed from a novel master equation and two Fokker Planck equations. Our results demonstrate that the mathematical modeling of Ca2 puffs has to account for the discrete character of the Ca2 release sites and does not permit a continuous description of the number of open channel