Human neurons from bone marrow

Bone marrow stem cells are able to differentiate into a number of cell types, including liver, lung, and neuronal cells in rodents, but it has been unclear if cells transplanted into human brains can differentiate into neurons. In the January 21 early edition of the Proceedings of the National Academy of Sciences of the United States of America, Eva Mezey and colleagues at the National Institutes of Health, Bethesda, Maryland, US, show that transplanted bone marrow generates new neurons in human brains (PNAS, DOI:10.1073/pnas.0336479100, January 21, 2003.).

Mezey et al. examined post-mortem brain samples from females who had previously received male bone marrow cell transplants. They examined sections from different brain regions from all four patients and observed that a number of cells (including neurons) contained Y chromosomes. This was particularly marked in samples from the hippocampus and cerebral cortex. One 3-year-old patient (who lived the...