Abstract
The arcuate nucleus of the hypothalamus is arguably the most important nucleus for regulating energy homeostasis and metabolism. Since its initial description in the human brain, its function in metabolic regulation has been studied extensively. Key neuronal populations such as agouti-related peptide and pro-opiomelanocortin neurons have been discovered to play critical roles in feeding and body weight regulation. Recent studies have started to reveal the functional significance of other neuronal populations, especially those that promote feeding (orexigenic neurons). In this review, we discuss the history and key findings of the arcuate nucleus, with a focus on orexigenic neurons. We also highlight current challenges and knowledge gaps that remain to be addressed in future studies.