Effective colonic motility involves an intricate pattern of excitatory and inhibitory neuromuscular signals that arise from the enteric neural circuitry of the colon. Recent investigations have demonstrated that inflammation leads to a variety of changes in the physiological properties of the neurons in this circuitry, including hyperexcitability of neurons at the afferent end of the peristaltic reflex, synaptic facilitation, and attenuated inhibitory neuromuscular transmission. Furthermore, links have been established between these changes and disrupted motor activity in the colon, and we now know that some of these changes persist long after recovery from inflammation. It is highly likely that inflammation-induced neuroplasticity, which is not detectable by clinical diagnostics, contributes to disrupted motility in active and quiescent inflammatory bowel disease and in functional gastrointestinal disorders.
Gary M. Mawe
The basic elements of the peristaltic reflex circuit in the colon and changes detected at specific sites of this circuitry in colitis.