Miftakhov, Abdusheva, Christensen, 1999

Model Status

This is the original unchecked version of the model imported from the previous CellML model repository, 24-Jan-2006.

Model Structure

Intestinal motility describes the rhythmic, propulsive contractile activity of the distal stomach, intestine and colon. Peristaltic waves are generated through interplay between the enteric nervous system, smooth muscle cells and interstitial cells of Cajal (ICC). ICC are critical for initiating slow wave activity, making ICC the pacemakers of the gut. The slow wave membrane depolarisations, generated by ICC, determine the maximum frequency and the propagation characteristics of the intestinal rhythmic contractions.

Smooth muscle contraction is the fundamental event in gastrointestinal motion. Smooth muscle cells respond to the slow wave activity imposed by ICC pacemaker cells. Although many of the biochemical mechanisms underlying the excitation-contraction coupling are not yet defined, it is known that cytosolic Ca²⁺ is the essential component in the coupling phenomenon. Slow wave membrane depolarisation activates smooth muscle contraction, mainly by triggering an L-type Ca²⁺ current. This is the main source of Ca²⁺ for contraction.

Since the late 1960s, slow wave propagation in the gastrointestinal tract has been the subject of mathematical models. In 1968 Nelson and Becker proposed that a chain of relaxation oscillators could simulate the electromechanical activity in the small intestine. For the next two decades this idea persisted. However, more recently core conductor models, which consider the ionic fluxes and the electrical activity of individual cells, have been developed.

In 1999, Miftakhov et al. published a mathematical model, which aimed to simulate motility patterns of the small bowel. Within the functional unit of an electromyogenic syncytium are equations that represent the dynamics of ion channels in smooth muscle cells. These include voltage-gated Ca²⁺ channels (L and T-type), a voltage-gated K⁺ channel, a calcium-activated K⁺ channel, and a leak chloride current. The kinetics of these ion channels determine the electrical activity of the whole functional unit.

The complete original paper reference is cited below:

Numerical Simulation of Motility Patterns of the Small Bowel. 1. Formulation of a Mathematical Model, R. N. Miftakhov, G. R. Abdusheva and J. Christensen, 1999, Journal of Theoretical Biology , 197, 89-112. (A PDF version of the article is available to subscribers on the Science Direct.) PubMed ID: 10036210

The raw CellML descriptions of the model can be downloaded in various formats as described in .

The myoelectrical activity of the gastrointestinal smooth muscle cell is governed by the dynamics of voltage-dependent Ca²⁺ L and T-type channels (I_Ca,L and I_Ca,T ), a voltage-gated K⁺ channel (I_K ), a calcium-activated K⁺ channel (I_Ca-K ), and a leak chloride current (I_Cl ).