Gastric dysmotility in Parkinson's disease is not caused by alterations of the gastric pacemaker cells

Physiology of gastric motility and the gastric migrating motor complex. Motilin and increased luminal pressure stimulate the release of 5-HT from duodenal enterochromaffin cells. The released 5-HT activates 5-HT3 receptors, and the signal is transduced via the vagus nerve afferents to the nucleus tractus solitarius. The vagus nerve stimulates gastric smooth muscle cells via myenteric neurons and interstitial cells of Cajal. Thus, motilin and 5-HT induce phase II and III of the migrating motor complex via the vago-vagal reflex. Figure adapted from Takahashi and Itoh.11,1