Calcium signaling is one of the most important intracellular signaling mechanisms. A rich spatio-temporal repertoire of calcium signals is observed across cell types, with patterns exhibiting a hierarchical structure varying from single channel transients to Ca²⁺ waves, sweeping the entire cell [36]. At the heart of the signaling mechanism is the inositol 1,4,5 trisphosphate (IP₃) receptor, a calcium channel regulated by a second messenger and calcium itself. Significant efforts have been made to characterize the properties of the IP ₃ receptor and how it is regulated. Multi-scale computational modeling plays a significant role in testing hypotheses and providing feedback to experimental research.

The aim of this dissertation is to develop a simple mathematical model for an IP₃ receptor, which quantitatively describes the properties of elemental calcium release events, i.e Ca²⁺ puffs. A simple, and computationally efficient and accurate model for the elementaryCa ²⁺ release events forms the building block for simulations on a larger organizational scale. A sequential binding model, for the IP ₃ receptor, is proposed in this dissertation. The model is then compared to other models proposed in literature. On the organizational scale of a cluster of IP₃ receptors, predicted properties of the various models are compared. The role of buffers, in calcium cluster release is also investigated.