Hypothalamic paraventricular nucleus: interaction between α2-noradrenergic system and circulating hormones and nutrients in relation to energy balance

摘要: Extensive evidence suggests that norepinephrine (NE) in the brain is active control of eating behavior. Central injection studies demonstrate a stimulatory effect NE on food intake, response which mediated by α2-noradrenergic receptors located medial hypothalamus, particular paraventricular nucleus (PVN). Activation these PVN stimulates ingestion specifically carbohydrate-rich foods, and this believed to reflect role endogenous controlling natural appetite for macronutrient. This system appears be physiologically activated at onset animals' cycle, when there peak preference carbohydrate. At time, adrenal hormone corticosterone, known play major carbohydrate metabolism, found interact positively with potentiation ingestion. Circulating glucose also influences activity and, moreover, α-noradrenergic stimulation produces an increase circulating levels both corticosterone glucose. other has led hypothesis PVN, through activation glucocorticoid- glucose-sensitive α2-receptor sites, energy homeostasis, most particularly animal's cycle. Specifically, neurotransmitter evokes state conservation. involves adjustments as well allow animals maintain reserves anticipating or responding depletion.