Chapter 7: Central Ghrelin Receptor and Food Intake

MARIO PERELLO; JESICA RAINGO

Central functions of the Ghrelin Receptor

Springer

Año: 2013;

Feeding is a vital function that provides nutritional and energy metabolism needs for animals. To ensure feeding, mammalian brains possess several interrelated neuronal systems that regulate different aspects of feeding behaviors.These neuronal circuits controlling food intake are strongly regulated by peripheral signals that contribute to the fine regulation of the energy homeostasis, such as metabolites and hormones. Among the signals regulating food intake, the stomach-derived hormone ghrelin and its receptor [named ghrelin receptor or the growth hormone secretagogue receptor type 1a (GHSR-1a)] play a major role. Ghrelin is the only mammalian peptide hormone able to increase food intake. Ghrelin stimulates appetite by affecting both food intake itself and also the rewarding aspects of feeding. As discussed below, the central distribution of GHSR-1a supports the concept that ghrelin regulates both homeostatic and hedonic aspects of feeding, and evidences from different studies confirm that ghrelin promotes food intake via diverse mechanisms. Of note, derangements in the ghrelin/GHSR-1a system have been reported in several eating disorders, including obesity, anorexia nervosa, bulimia nervosa, binge-eating disorders, cachexia and Prader-Willi syndrome. Here, the potential pathways by which GHSR-1a regulates feeding, with a special focus on hedonic aspects of eating, are delineated. Also, recent evidences suggesting a role of the ghrelin system on eating disorders are briefly reviewed.