Boosting gut endocrinology with brain imaging.

摘要

The increasing incidence of obesity and associated diseases has spurred enormous interest in the mechanisms controlling feeding and energy homeostasis. Peripheral signals involved in regulation of body weight may be classified into those that are long acting, such as leptin and insulin, whose plasma levels reflect energy stores in adipose tissue and act via a negative feedback mechanism in the hypothalamus, brain-stem, and other areas of the brain to influence food intake, energy expenditure, and neuroendocrine responses. Short-acting signals emanating from mechanoreceptors and chemorecep-tors detect changes in gut distension and nutrients, and trigger the release of hormones to regulate intestinal motility, satiation, meal termination, and insulin secretion. Short-term gut signals are typically transmitted by vagal afferents to the brainstem and then relayed to the hypothalamus and other areas of the fore-brain.