The gastrointestinal tract receives a portion of its extrinsic nerve supply via the vagus nerve. Vagal motor fibers controlling gastrointestinal motility and secretion originate in distinct areas of the brainstem, specifically in the dorsal motor nucleus of the vagus (DMV) which, thus, represents the final integration site of the circuits that form the basis of gastrointestinal reflexes. The integrative circuitry involved in these reflexes is, as yet, unknown. In order to understand the ways, in which the brain influences and controls the gastrointestinal tract, one must understand the cellular basis of the nuclei involved in its function. The experiments planned in this application will combine state of the art electrophysiological recordings from identified gastrointestinal motoneurons in brainstem slices with morphological reconstructions to examine the hypothesis that the DMV is organized so that neurons with similar properties control selectively specific areas of the GI tract. We aim to test this hypothesis by correlating the location, morphology and target organ of DMV neurons with their cellular properties.
We expect that the results of these studies will provide new insights into the neurophysiology of the DMV and allow us to make a major contribution to our understanding of the central nervous system regulation and coordination of GI function.
