PARKINSON'S DISEASE

Parkinson's disease is a degenerative disease of the region of the brain containing the nigral neurons. These cells produce dopamine, a chemical that transmits signals between neurons. Degeneration results in the loss of control of movements. By the time the first symptoms are detected, more than 75 percent of the dopamine cells have died. This disease affects about 1 million people in the United States.

For ten years now, researchers in Sweden have been injecting Parkinson's patients with dopamine-producing cells from human fetal tissue. Mobility has been improved in some while others only experience partial improvements or none at all.[1] A similar study is presently being conducted at Mount Sinai Medical Center in New York. This mode of treatment will never become routine because cells from at least 6 fetuses must be used for each patient, which is both a problem of supply and ethics.

… In 1998, researchers at the National Institute of Neurological Disorders and Stroke (NINDS) isolated and grew rat neural stem cells in the laboratory where they developed networks and began producing dopamine. The cells were then injected into the brains of rats whose dopamine-producing areas of the brain had been removed, causing them to develop Parkinson's. The injections dramatically improved the rats' symptoms, about 75 percent motor function improvement after 80 days. [2]

Scientists believe that Parkinson's disease may be an ideal application for stem cells because chemical systems are easier to work with than sensory or visual systems where connections must be made correctly between neurons. The difficulty in the chemical application is in generating enough cells through stem cells isolation and growth and getting the stem cells to differentiate into the specific nigral neurons needed. Stem cell therapy is also ideal because the damage from Parkinson's is contained to one area of the brain and one type of neuron.