Hepatic-portal vein infusions of glucagon-like peptide-1 reduce meal size and increase c-Fos expression in the nucleus tractus solitarii, area postrema and central nucleus of the amygdala in rats

Appetite and hedonism: gut hormones and the brain

Precise automatic control of food intake and energy expenditure maintains a steady weight and is fundamental to survival. The brainstem and hypothalamus are key areas within the brain that integrate peripheral signals from the gut and adipose tissue to control feeding behavior according to energy need. Gut hormones are released after a meal and signal to the brain to initiate meal termination and feelings of satiation. However, reward pathways are able to override this mechanism so that when palatable food is presented, food is consumed irrespective of energy requirements.

Molecular neuroendocrine targets for obesity therapy

PURPOSE OF REVIEW

Although energy balance is tightly regulated in order to maintain a specific level of adiposity, the incidence of obesity continues to increase. Consequently, it is essential that effective therapeutics for the treatment and prevention of obesity be developed. This review provides a brief update on some recent advances in the characterization of neuroendocrine targets for obesity therapy.

RECENT FINDINGS

During the review period, considerable progress occurred in the understanding of previously described neuroendocrine regulators of energy balance, and several novel targets have been identified. Moreover, the understanding of the neural circuitry and molecular mechanisms of the neuroendocrine regulation of energy homeostasis has been expanded.

SUMMARY

Energy balance is maintained by neuroendocrine signals arising from many tissues including the gastrointestinal tract and adipose tissue. These signals are integral to the cessation of meals and to the ability of the brain to monitor energy status and respond accordingly. Many current targets for obesity therapy are based on manipulating the activity of these signals and their receptors; however, to date, clinical-weight loss based on this strategy has been minimal and alternative approaches such as combinatorial therapies are emerging.