Insulin plays an important role in the brain, and impaired brain insulin signaling may affect energy regulation, synaptic function, learning, and memory. Although insulin is typically discussed in relation to blood glucose and peripheral metabolism, the brain also contains insulin receptors that influence several processes involved in neuronal health and function.

The authors examine the growing connection between impaired insulin signaling and Alzheimer’s disease, including evidence suggesting that brain insulin resistance may contribute to changes in cognition and neuronal function. They also discuss the potential of intranasal insulin as a way to deliver insulin directly to the brain, bypassing some of the limitations of peripheral insulin administration.

The bigger question is whether Alzheimer’s disease should be viewed, at least in part, through a metabolic lens. The evidence does not mean that Alzheimer’s is simply “diabetes of the brain,” but it does highlight the importance of understanding how insulin signaling, cellular energy metabolism, and brain health intersect—and whether targeting these pathways could offer new approaches to prevention or treatment.

https://www.sciencedirect.com/science/article/pii/S002839081730566X