The rats regained much of their motion, which is encouraging news. There are certainly more details to this study. You can read this story from the Medical College of Georgia's Web site to learn more. (Side note: We have not yet confirmed whether the stem cells were adult or fetal stem cells. The source is a reputable fetal stem cell scientist, but we should never assume.)
After hearing that story, we are all encouraged by another small step in stem cell research. The less optimistic study number two, published in November's Nature Medicine comes from a University of Rochester Medical Center and Cornell Medical College team. It involved transplanting human fetal stem cells into rodent brains. While many of the Parkinsoninan rats in this study improved with the stem cell transplants, many also developed problems. After transplantation the stem cell grafts started to show areas that no longer consisted of dopamine-releasing neurons, but of dividing cells that had the potential to give rise to teratomas, or tumors made up of a number of different tissues. The authors believe their findings mandate caution before moving the application of such stem cell-derived grafts to the clinic as a possible treatment for Parkinson's disease. You can read more about this study on the UPI Web site.
If scientists can coach the stem cell grafts to remain brain cells rather than developing into other types of cells, stem cell science may be able to move forward.
