Instituto superior de ci ncias da sa⁄de

TL;DR: The regulation of feeding behavior also involves the monoamines dopamine, noradrenalin and serotonin involved in the reward center, a system that values the intake by the feeling of pleasure, and the endocannabinoid system that protects from anxiety and stimulates feeding.

Abstract: 5 Abstract Feeding behavior depends on the balance between food intake and energy expenditure. This regulation occurs in the brain where the hypothalamus plays a key role. The hypothalamus receives adiposity signals by insulin and leptin that gives information about the state of energy reserves. When their levels are low, hypothalamus nuclei send signals through the orexigenic neuropeptides NPY, AgRP, CRH and orexins and ghrelin, a peripheral peptide that stimulate food intake. During ingestion, the first signals received by the brain are the pleasure channeled through the reward system, and the distension of the stomach that is communicated to the brainstem via the vagus nerve. Digestion causes the release of hormones that act as peripheral satiety signals, operating in the brainstem or in the arcuate nucleus (ARC) of the hypothalamus. Examples of such hormones are amylin, pancreatic polypeptide (PP), oxyntomodulin (OXM), cholecystokinin (CCK), glucagon-related peptide (GLP1) and peptide YY (PYY). The regulation of feeding behavior also involves the monoamines dopamine, noradrenalin and serotonin involved in the reward center, a system that values the intake by the feeling of pleasure, and the endocannabinoid system that protects from anxiety and stimulates feeding. Actually, there are few alternative drugs to treat obesity that are effective and safe because the pathways involved in feeding behavior are often easily compensated by other pathways, and are involved in the regulation of other systems.