Study: Brain genes may slow down at age 40
Researchers from the Children's Hospital and Harvard Medical School say they've found a "genetic signature" of aging in the human brain -- showing certain genes slow down after the age 40, according to a study published online by the journal Nature.
The researchers analyzed brain tissue from the frontal cortex in 30 deceased people ranging in age from 26 to 106. They studied nearly 11,000 genes.
After age 40, about 400 genes showed significant changes in how hard they had been working to instruct cells to make certain proteins, the study said. Less than half of the 400 genes were found to be functioning at a lower level, perhaps due to damage. These were associated with learning, memory and communication between brain cells.
The remaining genes were found to be working harder after age 40, the researchers found. They included genes involved in DNA repair, antioxidant defense and stress and inflammatory responses.