Young Blood Boosts Brains of Old Mice
The discovery might have implications for aging humans, study authors suggest
By Robert Preidt
MONDAY, May 5, 2014 (HealthDay News) -- Lending credence to the old saying that there's nothing like young blood, a new study found that the brains of old mice were recharged when they were injected with blood from young mice.
If this approach works in people, it could be used to give a boost to aging brains or lead to new ways to treat Alzheimer's disease and other types of dementia, according to researchers at Stanford University School of Medicine.
The researchers examined a brain structure called the hippocampus in old mice with circulatory systems that had been surgically connected with the circulatory systems of young mice or other old mice. The hippocampus plays an important role in memory, but becomes less effective during the aging process.
"We know that detrimental anatomical and functional changes occur in the hippocampus as mice and people get older. This is just from natural aging. We're all heading in that direction," study lead author Saul Villeda said in a Stanford news release.
The researchers found that the hippocampi of old mice linked with young mice more closely resembled those of younger mice than the hippocampi of old mice connected with other old mice. The findings were published online May 4 in the journal Nature Medicine.
For example, hippocampal cells in old mice paired with young mice made higher levels of substances the cells typically produce when learning is taking place. And hippocampal nerve cells in old mice paired with young mice also showed an improved ability to strengthen their connections with one another, which is essential to learning and memory.
"It was as if these old brains were recharged by young blood," study senior author Tony Wyss-Coray, a professor of neurology and neurological sciences at Stanford, said in a university news release.
In the next phase of its research, the team injected plasma -- the cell-free part of blood -- from young mice into old mice. These old mice did better on memory tests than old mice that did not receive plasma from young mice.