Theoretical Study On Synchronization Of Calcium Oscillations In Coupled Hepatocytes

Cell is the basic element of structure and function in organism. Calcium ion (Ca²⁺) is one of the most important intracellular signal messenger, which participates almost all life functions, such as cell division, matter transportation, and etc. Moreover, Ca²⁺ oscillation in cytoplasm denotes a typical periodic movement on cellular level and implies physiological significance. Recently, applying nonequilibrium statistical physics to intracellular Ca²⁺ signal has become one of the important forward subjects in today's biophysics. Employing theoretics and methods of nonlinear stochastic dynamics, this dissertation investigates mechanics and synchrony of Ca²⁺ oscillations in coupled hepatocytes.In order to explain experiments of Ca²⁺ oscillations in coupled hepatocytes, some theoretical models had been proposed. Although these models about Ca²⁺ dynamics are relatively successful, they had limitations. For examples, effects of IP₃ (inositol 1,4,5-trisphosphate, an important second messenger, can combine and activate Ca²⁺ channels on endoplasmic reticulum, ER) had been ignored; effects of noise on synchronization had been ignored; multicellular system had not been considered. Therefore, based on previous investigation of Ca²⁺ dynamics in coupled cells, from the deterministic level to the stochastic level, and from a single cell to a multicellular system, this dissertation deeply studied effects of coupling strength, IP3 level, noise, and etc, on synchrony of Ca²⁺ oscillations in coupled hepatocytes.