Hypothalamic Melanocortin System on Feeding Regulation in Birds: A Review

Regulation of feed intake in chickens represents a complex homeostatic mechanism involving multiple levels of control. Understanding the regulation of feeding behavior can be a very important theme in animal production. Recently, a close evolutionary relationship between the peripheral and hypothalamic neuropeptides has become apparent. In the infundibular nucleus (the avian equivalent of the mammalian arcuate nucleus), the melanocortin system, which contains neuroendocrine neurons that regulate endocrine secretions by releasing substances, is an essential site in the brain for signals about the status of peripheral energy balance. The structure and function of many hypothalamic neuropeptides, melanocortins, neuropeptide-Y (NPY) and agouti-related protein (AGRP) have been characterized. This review provides as overview of the various effects and interrelationship of these central and peripheral neuropeptides, and summarizes the role of the melanocortin system on feeding regulation in chicks.