[Interactions between the brain and gastrointestinal tract]

Peptides have been implicated to subserve neurotransmitter function within the brain and the gastrointestinal tract. While the anatomical distribution of neuropeptides suggest that most neuropeptides identified in brain tissue are also present in the gastrointestinal tract and vice versa, the functional interrelationship of the central nervous system and the gastrointestinal tract are less well documented. Most studies examined the peripheral actions of peptide hormones on visceral functions. This paper summarizes the central nervous system actions of neuropeptides on various gastrointestinal entities (secretion, motility, blood flow, absorption and eating behavior). This paper also deliniates the efferent and afferent pathways that allow to occur communication of the brain and the gastrointestinal tract. From this summary it will become evident that over the past ten years progress has mainly been made in the understanding of how the brain regulates gastrointestinal functions and only little knowledge has been accumulated to improve the understanding of afferent information flow from the gut to the brain.