Departmental Colloquium - Gut Feelings: A data driven approach to modelling the dynamics of the proximal colon (Bard Ermentrout)

The classic view of the colon is based on the physiology of the distal colon which propels fecal pellets by generating smooth muscle contraction orally and relaxation aborally. This behavior requires the presence of the pellet to activate the sensory motor program. In contrast, no pellets have yet formed in the proximal colon. Furthermore, in absence of any fecal contents, the proximal colon produces regular rhythmic propagating contractions with a period of 2-5 minutes in the mouse. We present new experimental results that shed light on the possible mechanisms for these contractive waves. We use the new experiments to suggest a computational model of the proximal colon. We show that the combination of the circular muscle, sensory neurons unique to the proximal colon, and specialized pacemaker cells, create a double chain of oscillators that is able to reproduce the observed dynamical behavior. By breaking the model into its component parts, we are able to provide a mathematical explanation for the slow rhythmic contractions. We use the model to explain pathological motility patterns in experimentally induced inflammation.