Bone to brain

AUTOPSIES ON four women have proved that stem cells from bone marrow do not just turn into blood and bone. They can turn into brain cells too, according to a report in New Scientist. The discovery could lead to new treatments for brain damage and degenerative diseases such as the Alzheimer's.

All four women had received bone transplants from men. Eva Mezey's team at the U. S National Institute of Neurological Diseases and Stroke found that some cells in their brains carried the y chromosome, which could only have come from the marrow. Mezey thinks that stem cells probably circulate and are drawn into damaged organs, by chemical signals from injured cells.