Mathematical models for understanding various biological functions at the cell level

Abstract

What makes the heart beat? This has been one of the fundamental questions of researchers in the field of cardiac physiology. In electrophysiology, cardiac pacemaker cells are characterized as cardiomyocytes possessing automaticity, which is caused by the slow diastolic depolarization toward a threshold potential. Our simplified action potential model, in which the cell is represented as an electrical equivalent circuit consisting of conductances, batteries and a capacitor, greatly facilitates understanding of the basic mechanisms underlying characteristic behavior of the cardiomyocytes and explains automaticity in the pacemaker cell as the transition of the instantaneous equilibrium potential of the membrane capacitor. Possibilities of using simplified mathematical models in parallel with realistic models for deeper understanding of cell functions will be discussed.