Transplanted Brain Cells Hold Promise for Parkinson’s Disease

Transplanted neural stem cells hold promise for Parkinson’s disease, scientists say.

Research published in the Nov. 29, 2006 issue of The Journal of Neuroscience shows a human neural stem cell transplant enables an animal with 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,” said Dr. Cesario

V. Borlongan, an MCG neuroscientist and corresponding author of the study.

The rats in the study received the transplanted cells shortly after Parkinson’s was induced by destroying neurons that make dopamine, a neurotransmitter key to movement control. This would be equivalent to a patient getting treatment very soon in the disease process, which rarely happens since there is no screening test to catch it early.

“If you are able to identify Parkinson’s in the early stage, we think this therapy will work,” said Dr. Borlongan. “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 regained movement control, placebotreated 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—a long time in the twoyear life of a rat—researchers found endogenous dopaminergic cells and transplanted neural stem cells had both survived. Also, transplanted neural cells had formed synapses to communicate with each other and ultimately the striatum, the portion of the brain dopaminergic cells act on to control movement.

“The transplanted stem cells survived, differentiated into neurons and showed some connection with the host tissue,” said Dr. Borlongan.

Toni Baker