STANFORD, Calif. -- Researchers at the Stanford University School of Medicine have illuminated the path taken by human neural stem cells that were transplanted into the brains of rats and mice, and found that the cells successfully navigate toward areas damaged by stroke.

The research group placed miniscule particles of iron inside stem cells to act as cellular beacons detected by magnetic resonance imaging. With the ability to monitor where the human stem cells go in real time, researchers will have an easier time learning the best way of using the cells to treat human neural disorders, such as stroke, traumatic brain injury, Parkinson's disease or radiation damage.

The findings, to be published in the June 4 advance online version of the Proceedings of the National Academy of Sciences, could eventually make it possible to track human stem cells that are transplanted into the brains of patients.

Gary Steinberg, MD, PhD, who led the research group, said the work also shows that the iron doesn't disrupt the normal function of the stem cells. "This work is important because if a method of tracking the cells changes their biology, it will not be helpful," said Steinberg, senior author of the paper and the Bernard and Ronni Lacroute-William Randolph Hearst Professor in Neurosurgery and Neurosciences.

In a 2006 study, Steinberg and his colleagues had shown that the same human stem cells used in this study were able to migrate toward a brain region in rats that mimicked a human stroke. They also found that those cells matured into the types of cells they would expect to find in that part of the brain.

The only problem was that in order to find out where the cells ended up, they had to kill the rats - not an approach that can be used for human clinical trials. What the researchers needed was a way of tracking the stem cells in real time to find out whet
'"/>

Contact: Amy Adams
amyadams@stanford.edu
650-723-3900
Stanford University Medical Center
4-Jun-2007