The role of tanycytes in the regulation of energy balance

The hypothalamus serves as a central regulator of energy homeostasis by integrating peripheral metabolic cues and coordinating neuroendocrine, autonomic and behavioral responses. Within this system, tanycytes—specialized ependymoglial cells lining the third ventricle—occupy a unique anatomical and functional position at the interface between the cerebrospinal fluid, hypothalamic parenchyma and the fenestrated capillaries of the median eminence. These polarized cells form a dynamic barrier that regulates the access of circulating hormones and nutrients to hypothalamic neurons and actively participate in the bidirectional communication between the brain and periphery. Tanycytes transport key metabolic signals such as leptin, ghrelin, insulin and glucagon-like peptide-1 receptor agonists, and act as nutrient sensors for glucose, amino acids and fatty acids, thereby linking systemic energy status to central metabolic control. Importantly, tanycytes also serve as a source of neural stem/progenitor cells in the adult hypothalamus, generating new neurons and glia in response to metabolic and environmental stimuli. Their remarkable plasticity and responsiveness to physiological states underscore their role as central hubs in metabolic regulation.