A study, published in Proceedings of the National Academy of Sciences, was conducted at the Washington University School of Medicine in St. Louis to look at this possibility. Chemicals were applied to the spinal cords of a population of laboratory rats, which dissolved their myelin. Three days later, rat embryonic stem cells were transplanted into those injured rats' spinal columns. When the rats were sacrificed and autopsied, mature myelin producing cells were found at the site of the transplants. When these same embryonic cells were transplanted into rats that were genetically deficient in myelin production, they too were found to have mature versions of the embryonic transplanted stem cells-and those matured stem cells were producing myelin.

Further work in the same laboratory has been done on rats with induced spinal cord injuries. Nine days after injury, those rats were treated with embryonic stem cell transplants. After two to five weeks, those rats demonstrated improvement in weight bearing and coordination, and at autopsy, were found to have adult versions of the transplanted fetal cells. If these types of procedures are someday available to humans, their benefit to spinal cord injury patients could be enormous.

Multiple sclerosis is a disease in which demyelination, or loss of myelin, is a cardinal feature and the cause of the neurological deficits. Researchers are asking if stem cell therapy that induces remyelination might slow or reverse the neurological problems of multiple sclerosis. Researchers at Emory University in Atlanta published the results of a study in Nature Medicine. These researchers had transplanted stem cells of oligodendrocytes (cells from the central nervous system) into dogs with a demyelinating disease similar to human multiple sclerosis. They observed large areas of repair of the demyelinated areas after oligodendrocyte-precursor transplant. Much work remains to be done before these results can be translated into human therapies, but the potential for successful treatment for multiple sclerosis is exciting.