Turning blood into brain:: Cells bearing neuronal antigens generated in vivo from bone marrow

Bone marrow stern cells give rise to a variety of hematopoietic Lineages and repopulate the blood throughout adult Life. We show that, in a strain of mice incapable of developing colts of the myeloid and Lymphoid lineages,transplanted adult bone marrow cells migrated into the brain and differentiated into cells that expressed neuron-specific antigens. These findings raise the possibility that bone marrow-derived cells may provide an alternative source of neurons in patients with neurodegenerative diseases or central nervous system injury.