Neuroendocrinological Control of Obesity

A complex physiological system of afferent and efferent pathways provides the balance between energy intake and expenditure. Hunger initiates eating. Satiety hormones assist digestion and also partake in the feeling of satiety upon food intake. The central circuit in the brain, by integrating the satiety signals and the long term signals of energy status, coordinates the responses to the changes in the nutritional status. The primary determinant of energy intake is appetite regulation, consisting of central regulation and peripheral regulation. The central nervous system receives hormonal and metabolic signals from the periphery, of long term or of short term regulatory nature, which are interpreted and redirected to centers in the brain and peripheral organs to plan the energy homeostasis. This integrating regulation mostly takes place at the arcuate and the paraventricular nuclei of the hypothalamus. The arcuate nucleus neurons secrete orexigenic substances, such as neuropeptide Y and agouti-related peptide, and anorexigenic peptides such as pro-opiomelanocortin and cocaine- and amphetamine-regulated transcript.