Boyett, Zhang, Garny, Holden, 2001

Model Status

This model can not be solved as it is unsuitably constrained.

ValidateCellML verifies this model as valid CellML but detects unit inconsistencies.

Model Structure

In 2000 H. Zhang et al published a mathematical model which describes the action potentials in the periphery and center of the rabbit sinoatrial node. The SA node is functionally, anatomically and electrophysiologically heterogeneous. In their model, Zhang et al accounted for this heterogeneity by defining two distinct models for the peripheral and the central cells of the SA node. These models have the same equations to define the ionic currents but they vary in their parameters.

The complete original paper reference is cited below:

Mathematical models of action potentials in the periphery and center of the rabbit sinoatrial node, H. Zhang, A.V. Holden, I. Honjo, M. Lei, T. Varghese and M.R. Boyett, 2000, Am. J. Physiol. Heart Circ. Physiol. , 279, H397-H421. PubMed ID: 10899081

In 2001, Boyett et al reviewed the results of several experiments which suggested that intracellular calcium controls a number of ionic currents in the SA node cells. This had not been considered in previous SA node cell models and Boyett et al incorporated an intracellular calcium handling element into the model of Zhang et al (2000). In addition, they included a sustained inward current based on the experiments and equations of Shinagawa et al (2000) (see the figure below). Like in Zhang et al's orginal model, differences between the central and peripheral SA node cells are taken into consideration by defining different parameters. The CellML description here is of the peripheral SA node cell model. To make it appropriate for the central SA node cells, certain parameters need to be changed (refer to the original paper reference which is cited below).

Control of the pacemaker activity of the sinoatrial node by intracellular Ca²⁺. Experiments and modelling, M.R. Boyett, H. Zhang, A. Garny and A.V. Holden, 2001, Phil. Trans. R. Soc. Lond. A. , 359, 1091-1110.

A schematic diagram describing the current flows across the cell membrane that are captured in the Boyett et al 2001 model of the action potentials in the peripheral cells of the SA node.

The network defined in the CellML description of the Boyett et al 2001 model. For simplicity, not all the variables are shown.