Gut–brain nutrient sensing in food reward. (1st March 2018)

• Record Type: Journal Article
• Authors: Shechter, Ari; Schwartz, Gary J.
• Is Part Of: Appetite. Volume 122(2018)
• Page Start: 32
• Page End: 35
• Publication Date: 2018-03-01
• Subjects: Appetite -- Flavor conditioning -- Food intake -- Satiety -- Sugar -- Vagus nerve; Food habits -- Periodicals; Appetite -- Periodicals; Appetite disorders -- Periodicals; Electronic journals; 306.4613
• DOI: 10.1016/j.appet.2016.12.009
• Languages: English
• ISSNs: 0195-6663

Abstract

Abstract: For the past several decades, vagal and hormonal gut–brain negative feedback signaling mechanisms that promote satiety and subsequent suppression of food intake have been explored. In addition, a separate positive feedback process termed "appetition, " involving postoral signaling from the gut to the brain, has been shown to promote food intake and produce flavor–nutrient preference conditioning. Afferent fibers emerging from the vagus nerve form the main pathway by which information is relayed from the abdominal viscera to the hindbrain and eventually other higher brain regions involved in food intake. Using a specialized subdiaphragmatic vagal deafferentation technique, it was observed that gut vagal and splanchnic afferents play a role in the negative feedback control of satiety after nutrient intake; however, these afferents are not required for nutrient reinforcement or flavor–nutrient preference conditioning, thereby highlighting the distinction between the processes of satiation and appetition. By linking these physiological and behavioral processes to a neurochemical mechanism, it was found that striatal dopamine release induced by intragastric glucose infusion is involved in sweet appetite conditioning. The mechanisms underlying appetition are still being investigated but may involve other nondopaminergic neurochemical systems and/or presently undiscovered hormonal mediators. Future work to delineate the biological mechanisms whereby appetition drives increased intake and conditioned food preference in response to ingestion should take a multifaceted approach by integrating hormonal, neurophysiological, and behavioral techniques. Highlights: Various vagal and hormonal gut–brain negative feedback mechanisms promote satiety. A separate gut–brain positive feedback signal, "appetition, " was identified. Appetition promotes food intake and produces flavor–nutrient preference conditioning. This effect involves dopamine and possibly other neurochemical or hormonal systems.