Transplanted Brain Cells Hold Promise for Parkinson's Disease
Transplanted neural stem cells hold promise for reducing the destruction of dopaminergic cells that occurs in Parkinson's disease and for replacing cells lost to the disease, scientists say.
Research published in the current issue of The Journal of Neuroscience shows a human neural stem cell transplant essentially enables an animal model for Parkinson's to continue functioning normally rather than displaying the progressive loss of movement control that characterizes the disease.
"We are very cautious but to us, it's an indication that stem cells have promise for Parkinson's disease," says Dr. Cesario V. Borlongan, neuroscientist at the Medical College of Georgia and corresponding author of the study.
Transplants were done shortly after a neurotoxin was used to destroy neurons that make dopamine, a neurotransmitter key to movement control, Dr. Borlongan notes. This would be equivalent to a patient getting treatment very early in the disease process, which rarely happens since there is no screening test to catch it early.
"Right now we are saying if you are able to identify Parkinson's in the early stage, we think this therapy will work. An important question that remains is, 'Can we rescue neurons that are dying from Parkinson's?' This would more accurately mimic what patients need." The researchers already have begun studies that delay the transplants until weeks after injury.
For this study, researchers compared animals that received placebo treatment with those that received only protective neurotrophic factors secreted by stem cells and those that had a transplant.
Animals that received transplants essentially regained control of their movement, placebo-treated animals did not recover and those that received neurotrophic factors, called stem cell factors, recovered partially.
When researchers examined the brains one month after transplant