A Gene Expression Signature of Brain Aging is Most Distinct in White Matter

Researchers here report on a measure of brain aging constructed from expression levels of a variety of genes, noting that it appears to show the greatest changes in white matter rather than grey matter. They use this measure to assess the results of interventions shown to slow aging in old mice, calorie restriction and plasma transfer from young mice, finding that these two treatments have quite different mechanistic outcomes in the brain, slowing brain aging in quite different ways. This suggests that (a) there are multiple ways to intervene, and (b) there are ways to improve on present capabilities. Researchers sampled 15 regions in both hemispheres of the brains of 59 female and male mice aged 3 to 27 months. They identified and ranked the top genes expressed by cells found in each region of the brain. They identified 82 genes that are frequently found and vary in concentration in 10 or more regions. The team used these genes to develop a common aging score, assessing how gene activity in different regions of the brain change with age. The researchers found that the white matter, which is found deep in the brain and contains nerve fibers protected by white-colored myelin, showed the earliest and most pronounced changes in gene expression for mice 12 and 18 months old. These mice are about as old, in mouse years, as a person in their 50s. Past work has shown that aging disrupts an otherwise stable gene expression pattern in the brain, turning on genes that r...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs