Effects of Age and Diet on Insulin Signaling in the Rodent Brain

Age affects every brain, but the severity of its effects varies widely. One factor which may influence how the brain ages is the effectiveness of its insulin signaling, which in turn may be affected by both age and metabolic conditions such as obesity. The purpose of this study was to investigate if insulin signaling within the cerebral cortex varies with age and/or diet by using Western blot analysis. We studied levels of the following downstream proteins in the insulin signaling pathway: Insulin Receptor (IR), phospho‐AKT (pAKT), and phospho‐GSK3β (pGSK3). The rodent cortical tissues used for samples were prepared from C57Bl/6 mice which were fed a high fat diet (HFD) or a low fat diet (LFD) to create models in both young (Y) (3 months) and old (O) (20 months) animals. Our results suggest that IR levels do not change significantly with age or diet. Overall results suggest that age generally decreases levels of pGSK3 and pAKT irrespective of diet. This research has potential applications as increasing numbers of people regularly consume high‐fat diets, obesity and metabolic disorder rates increase, and average lifespan increases. The project described was supported by the National Center For Research Resources (Grant Number P20RR016456) and by the Louisiana Board of Regents Support Fund.