They found that mice with brain injuries that received the stem cells now remembered their surroundings about 70 percent of the time -- the same as healthy mice. However, mice that didn't receive stem cells still had memory deficits.
The researchers also found that in healthy mice injected with stem cells, the stem cells traveled throughout the brain. In contrast, stem cells given to injured mice lingered in the hippocampus. Only about 4 percent of those stem cells became neurons, indicating that the stem cells were repairing existing cells to improve memory, rather than replacing the dead brain cells, Blurton-Jones's team noted.
The researchers are presently doing another study with mice stricken with Alzheimer's. "The initial results are promising," Blurton-Jones said. "This has a huge potential, but we have to be cautious about not rushing into the clinic too early."
One expert is optimistic about the findings.
"Putting in these stem cells could eventually help in age-related memory decline," said Dr. Paul R. Sanberg, director of the Center of Excellence for Aging and Brain Repair at the University of South Florida College of Medicine. "There is clearly a therapeutic potential to this."
Sanberg noted that for the process to work with Alzheimer's it has to work with older brains. "There is clearly therapeutic potential in humans, but there are a lot of hurdles to overcome," he said. "This is another demonstration of the potential for neural stem cells in brain disorders."
For more information on memory, visit the U.S. National Library of Medicine.
SOURCES: Mathew Blurton-Jones, Ph.D., postdoctorate fellow, University of California, Irvine; Paul R. Sanberg, M.D., director, Center of Excellence for Agin
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