NEW YORK, Sep 14 (Reuters Health) -- Brain cells that have shrunk and lost their function due to aging or diseases such as Alzheimer's disease could possibly be returned to full function by gene transfer, according to US researchers who report that they have achieved that result in monkeys.
Dr. Mark Tuszynski, of the University of California, San Diego, and colleagues there and at the Salk Institute in La Jolla, counted specific cells in the brains of young and old monkeys. In the older monkeys, 43% of cells in the basal cortex -- a part of the brain that controls brain functions such as memory -- had stopped producing certain molecules needed for brain activity, and had shrunk or atrophied.
"With aging in monkeys, there is an atrophy, but not a death, of cells," Tuszynski told Reuters Health. "The good news is that, at least at this stage of aging, the cells are not yet dead, and that presents the opportunity to intervene and affect the aging process that causes cell atrophy."
In an effort to reverse the atrophy, the researchers implanted the genes for nerve growth factor, which stimulates neuronal growth, into the brains of four aged monkeys. "We were able to substantially reverse the atrophy" using this gene therapy approach, Tuszynski said.
He explained that the same group of cells that atrophied with aging in monkeys also withers and eventually dies in Alzheimer's disease, so that the next step is to see if the approach will work to reverse the cell degeneration in Alzheimer's disease. In June, Tuszynski and his group submitted a proposal to the US Food and Drug Administration to look at the safety of the procedure in patients with Alzheimer's disease. The FDA is still reviewing their proposal.
