The report by Fred H. Gage, Ph.D., and colleagues at the Salk Institute in La Jolla, CA, and Kumamoto University in Japan, appears in the July 15, 2004, issue of Nature.
Adult stem cells in the brain were proposed to be restricted to the generation of neurons and cells, such as glial cells, that support neuron function. Experiments over the past several years have raised the possibility that stem cells from the brain may be able to give rise to additional cell types, a phenomenon known as plasticity. But recent findings have challenged this theory, suggesting that many of these stem cells merely merge or "fuse" with an existing cell within a tissue forming a hybrid that takes on the pre-existing cell's functions.
"Resolving this issue is important because fused cells may have a different therapeutic potential than stem cells that differentiate into new cells, says Bradley C. Wise, Ph.D., of the NIA's Neuroscience and Neuropsychology of Aging Program. "While this new finding doesn't fully answer this vital question, it keeps open the possibility that adult stem cells from different organs one day may be harnessed to help prevent and treat neurological disorders."
In their experiments, Gage and his colleagues grew mouse brain stem cells, which form neurons and glial cells, in the same culture dishes with human endothelial cells, which form the lining of blood vessels. Over time, about 6 percent of the mouse neural stem cells began to show signs that they had developed into cells similar to endot
Contact: Doug Dollemore
NIH/National Institute on Aging