Jafri-Rice-Winslow Ventricular Model 1998

In 1998, M. Saleet Jafri, J. Jeremy Rice and Raimond L. Winslow published a model describing the ventricular action potential. By adding a more sophisticated model of calcium handling, this model builds upon the Di Francesco-Noble and the Luo-Rudy models (see the Luo-Rudy I and the Luo-Rudy II models with their accurate descriptions of membrane currents (see Figure 1 below). Prior to this paper, membrane currents and calcium subsystems had only been considered separately.

The complete original paper reference is cited below:

Cardiac Calcium Dynamics: The Roles of Ryanodine Receptor Adaptation and Sarcoplasmic Reticulum Load, M. Saleet Jafri, J. Jeremy Rice and Raimond L. Winslow, 1998, Biophysical Journal, 74, 1149-1168. (Full text and PDF versions of the article are available for Journal Members on the Biophysical Journal website.) PubMed ID: 9512016

The raw CellML description of the Jafri-Rice-Winslow model can be downloaded in various formats as described in the section “Download This Model”. For an example of a more complete documentation for an electrophysiological model, see The Hodgkin-Huxley Squid Axon Model, 1952.

Figure 1. A schematic diagram describing the current flows across the cell membrane that are captured in the Jafri-Rice-Winslow model.

Figure 2. The network defined in the CellML description of the Jafri-Rice-Winslow model. A key describing the significance of the shapes of the components and the colours of the connections between them is in the notation guide. For simplicity, not all the variables are shown.

The membrane physically contains the currents, exchangers and pumps, as indicated by the blue arrows in Figure 2. The currents act independently and are not connected to each other. Several of the channels encapsulate and contain further components which represent activation and inactivation gates. The addition of an encapsulation relationship informs modellers and processing software that the gates are important parts of the current model. It also prevents any other components that aren't also encapsulated by the parent component from connecting to its gates, effectively hiding them from the rest of the model.

The breakdown of the model into components and the definition of encapsulation and containment relationships between them is somewhat arbitrary. When considering how a model should be broken into components, modellers are encouraged to consider which parts of a model might be re-used and how the physiological elements of the system being modelled are naturally bounded. Containment relationships should be used to provide simple rendering information for processing software (ideally, this will correspond to the layout of the physical system), and encapsulation should be used to group sets of components into sub-models.

The CellML description of this model is available in a number of formats. If you have your browser set up to view text files served with the “text/xml” MIME type, then you can have a look at the XML file here. If not, you can save that file to disk by shift-clicking on the preceding link. A “pretty-printed” browsable HTML version of the XML file is available here — note that you cannot download and save this version for later viewing since it makes use of stylesheets for formatting. If you wish to save or print out the “pretty-printed” version of the XML, a PDF version is also available here. A gzipped tarball (the Unix equivalent of a winzip file) including this documentation, the raw XML and the pretty-printed PDF version of the XML is available here.

Here are those links again: