Faville, Pullan, Sanders, Smith, 2008

Model Status

This CellML model is known to run in both COR and PCEnv to replicate the published results. The units have been checked and are consistent. We'd like to acknowledge Richard Faville for his help in getting the CellML model to replicate his published model.

Model Structure

Phasic gastrointestinal (GI) muscle is able to autonomously generate rhythmic contractions independent of the enteric nervous system. The electrical activity that generates these rhythmic contractions are called slow waves, or pacemaker potentials (PP), and they are produced by a specialised group of pacemaker cells called Interstitial Cells of Cajal (ICC). They pass via gap junctions from the ICC to smooth muscle cells (SMC), activating L-type Ca2+ channels, Ca2+ influx and the contraction of the SMC. Full slow waves result from the summation of a large number of localised cellular membrane fluctuations, and are know as unitary potentials (UPs). These are generated at intracellular sites called pacemaker units, and are known to play an essential role in driving the coordinated contraction of GI muscles.

In the study described here, Richard Faville et al. have developed a mathematical model which quantitatively describes the transmembrane ion flows and intracellular Ca2+ dynamics from a single ICC pacemaker unit. They have combined experimental data with a theoretical hypothesis to produce a biophysically-based computational modelling framework that simulates ICC pacemaker activity on the pacemaker unit spatial scale.

A schematic diagram of the pacemaker unit illustrating all the compartmental volumes and ionic conductances, together with their interactions.

The complete original paper reference is cited below:

A Biophysically Based Mathematical Model of Unitary Potential Activity in Interstitial Cells of Cajal, R.A. Faville, A.J. Pullan, K.M. Sanders, and N.P. Smith, 2008, Biophysical Journal . (A PDF version of the article are available to journal subscribers on the Biophysical Journal website.) PubMed ID: 18339738