The research, by scientists at Harvard University, the University of California, Berkeley, Lawrence Berkeley National Laboratory, and the Max-Planck-Institute for Evolutionary Anthropology, will be reported this week in the open-access journal PLoS Biology.
"We were surprised both by the homogeneity of aging within the cortex and by the dramatic differences in aging between cortex and cerebellum," says Joshua B. Plotkin, a junior fellow in the Harvard Society of Fellows. "The fact that gene activity levels in the cerebellum remain more stable as a person ages suggests that this region of the brain experiences less oxidative stress and damage as part of normal aging."
"Much remains to be learned about how the brain ages and how changes in gene expression over time are related to brain activity," says Michael B. Eisen, assistant professor of molecular and cell biology at UC Berkeley. "Our analyses suggest that the different functions of different regions of the brain influence how they age, and that we can learn about functional variation and evolution by studying gene expression changes with age."
The researchers used data from gene chips to look at gene expression -- the degree to which various genes are turned "on" and "off" -- in five different regions of the brain's cortex. They found that in all five cortical areas, brain changes with aging were pronounced and consistent. Changes in gene expression in the cerebellum were smaller and less coor