Stem Cells Restore Memory in Mice

By Steven Reinberg
HealthDay Reporter
Thursday, November 1, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, Oct. 31 (HealthDay News) -- A new U.S. study involving mice suggests the brain's own stem cells may have the ability to restore memory after an injury.

These neural stem cells work by protecting existing cells and promoting neuronal connections.

In their experiments, a team at the University of California, Irvine, were able to bring the rodents' memory back to healthy levels up to three months after treatment.

The finding could open new doors for treatment of brain injury, stroke and dementia, experts say.

"This is one of the first reports that you can take a stem cell transplantation approach and restore memory," said lead researcher Mathew Blurton-Jones, a postdoctorate fellow at the university. "There is a lot of awareness that stem cells might be useful in treating diseases that cause loss of motor function, but this study shows that they might benefit memory in stroke or traumatic brain injury, and potentially Alzheimer's disease."

In the study, published in the Oct. 31 issue of the Journal of Neuroscience, Blurton-Jones and his colleagues used genetically engineered mice that naturally develop brain lesions. The researchers destroyed cells in a brain area called the hippocampus. These cells are known to be vital to memory formation and it is in this region that neurons often die after injury, the researchers explained.

To test the mice's memory, Blurton-Jones's group conducted place and object recognition tests with both healthy mice and brain-injured mice.

Healthy mice remembered their surroundings about 70 percent of the time, while brain-injured mice remembered it only 40 percent of the time. For objects, healthy mice recalled objects about 80 percent of the time, but injured mice remembered them only 65 percent of the time.

The researchers then injected each mouse with about 200,000 neural stem cells.

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.