Governments are cautious yet increasingly open to the new research, which may eventually yield treatments for a variety of diseases from Parkinson's to diabetes. Dr. Eva Mezey of the National Institute of Neurological Disorders and Stroke, first author of the other study in Science , agreed that the researchers may have found a way the body replaces neurons. She said there's no awareness of the repair because the process replaces a neuron as soon as the cell fails. The studies are the latest in a hot new field of research exploring the ability of adult stem cells to transform themselves into other types of cells and to fill new roles in the body.
Bone marrow consists of at least two types of stem cells.
Earlier studies have shown these cells can convert themselves into muscle, bone, and liver. There also have been studies showing that neural stem cells can convert into muscle or make a variety of brain cells. In Blau's study at Stanford, researchers obtained bone marrow from a strain of mice that carry in each cell a protein that glows in the dark . Bone marrow was injected into the tail vein of mice whose natural bone marrow had been killed by radiation. Later, the mice were killed and their brains examined.