DURHAM, N.C. -- Researchers have shown for the first time that putting two specific types of neural cells directly into an aging brain can kick-start creation of brain cells linked to learning and memory.
In older people and people with Alzheimer's disease "neural stem cells are sitting there but not dividing, so they are not making new neurons," said Ashok K. Shetty, Ph.D., professor of neurosurgery at Duke and medical research scientist at the Durham Veterans Affairs (VA) Medical Center. "We hope that by making more neurons, we can improve learning and memory" in compromised patients.
Shetty and colleagues have shown that implanting specific brain cell precursors into the hippocampus region of aging rats increases neurogenesis, a first step in working toward therapies for humans. The results of their work appear in the August issue of the journal Stem Cells.
Two types of cells were harvested from the spinal cords of rats and then grafted into the aging rat hippocampus. After three weeks researchers saw an increase in neurogenesis in the rats that received the cell implants compared to rats that did not receive any treatment and rats that received implantation surgery but not receive stem cells. This is the first evidence that introduction of these two kinds of neural stem cells stimulate neurogenesis in the hippocampus.
The hippocampus has been linked to not just memory formation and storage in the brain, but also depression and neurodegenerative diseases such as Alzheimer's.
"Any strategies for improving neurogenesis in aging animals may be helpful to humans," said Shetty. The research was supported by the National Institutes of Health (NIH) National Institute on Aging as well as the National Institute of Neurological Disorders and Stroke and the Department of Veterans Affairs.
The researchers believe that the precursor cells secreted nerve growth factors that stimulated the inactive stem cells of the aging hippocampus to start dividing again. They also did a study that injected nerve growth factors directly to see if they would stimulate neurogenesis. Publication of study results is expected by the end of the year.
We need biotechnology that can take our cells, repair them, and then turn them into various types of stem cells. Once we can produce an assortment of types of youthful stem cells then we'll be able to start slowing and reversing the aging process. How soon will this happen? I do not know. But it would happen sooner if we tried harder to make it happen.