How Do Our Brains Change as We Age?

Abstract

Aging, which is a natural process in which an organism’s functions decline, is present in all living organisms. As we age, our brains begin to break down—certain brain regions get smaller and certain cell types decrease in number. These changes are similar to those seen in diseases like Alzheimer’s and Parkinson’s diseases. The similarities between aging and these neurodegenerative diseases tells us that the same genes might be affecting both processes. However, it is difficult to get samples of human brains to study aging, so we still do not understand what happens to genes in the various regions of the human brain during the aging process. Through global collaboration, a resource called the mouse brain Allen Brain Atlas (BrainMap) of 7 different cell types from cortex has been used, which is like a catalog of genes that are active in the human brain. We downloaded this database as used it as a comparative platform to our brain expression data. The study described in this article shows how protein coding regions of genes involved in different pathways are expressed across the brain, including in specific brain regions and specifically examining different cell type marker genes.