Age-Related Dynamics of Insulin Signaling in Neurons of the Rat Hypothalamic Tuberal Nuclei

The hypothalamus is a regulatory center that controls homeostasis,reproduction, circadian rhythms, and the endocrine system. It isalso involved in the regulation of aging. The expression of insulin receptors(INR) and insulin receptor substrate 1 (IRS1) was studied in neuronsof the arcuate (ARN), dorsomedial (DMN), and ventromedial (VMN)tuberal nuclei of the rat hypothalamus in young (2 months), adult(12 months), and old (24 months) male Wistar rats using immunofluorescencestaining and Western blotting. The results showed that INR and IRS1expression in neurons of the mediobasal hypothalamic nuclei changesin opposite directions with age. INR expression decreases in theARN and increases in the DMN and VMN, while IRS1 expression is unchangedin the ARN and VMN and decreases in the DMN.