Researchers at the University of California at Irvine announced in July that they were able to treat the bruised spines of rats by injecting the animals with human embryonic stem cells.
Dr. Hans Kierstead headed up the research which took human embryonic stem cells and modified them into cells that form the myelin sheath around nerve fibers (oligodendrocytes). The stem cells were then injected into the bruised spinal cords of the rats.
After a little more than two months, the formerly paralyzed rates regained the ability to walk. According to a report on the research in New Scientist,
Analysis of the rats’ spinal cords revealed that the transplanted oligodendrocytes had wrapped themselves around neurons and formed new myelin sheaths. The transplanted cells also secreted growth factors that appear to have stimulated the formation of new neurons.
Kierstead’s team repeated the experiment three times, finding similar results each time.
New Scientist also reports that another team, led by Douglas Kerr at John Hopkins University, also announced in late June that they had performed a similar experiment. Kerr’s team injected undifferentiated human embryonic stem cells into rats with injured spinal cords. The rats regained the ability to support their own weight again 24 weeks after the treatment.
Sources:
Human cells used to make paralyzed rats walk. Charles Arthur, The Independent, July 3, 2003.
Stem cells enable paralyzed rats to walk. New Scientist, July 3, 2003.