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New discovery in Parkinson's battle By Amanda Dunn Health Reporter August 18, 2003 A complex system of "trees" that distribute dopamine around the brain may hold the key to treating or preventing the development of Parkinson's disease. Dopamine - a neurotransmitter that produces a natural "high" when we do something we enjoy - is distributed around the brain from a central point called the substantia nigra. A shortage of dopamine caused by damage to the nervous system allows Parkinson's disease to set in. Researchers at Melbourne's Howard Florey Institute have discovered in animal studies that branches of the trees die off, causing the remainder to compensate by replacing them. "We think this branching process occurs because the remaining brain cells sense that loss of dopamine and make more branches so that the right amount of dopamine is released," deputy director Malcolm Horne explained. The researchers discovered that the receptors at the end of each tree branch, which regulate dopamine levels, also regulate the number of branches. But the new branches can compensate only for a limited time before the erosion outpaces it and Parkinson's disease sets in. The problem, Professor Horne said, is that the extra dopamine that the remaining branches produce to compensate for the erosion actually hastens the damage to the nervous system. It is at this point that early symptoms of the degenerative disease - slowness of movement, shaking - will begin to show. Professor Horne said one of the difficulties with identifying the disease was that by the time the first symptoms began to manifest, about 70 per cent of the nerve cells had died. The animal studies suggest that genes may predispose people to large or small trees. It appeared that those with smaller trees were more prone to addiction, and it may be that people with larger trees are predisposed to Parkinson's disease. A shortage of dopamine . . . allows Parkinson's disease to set in. While some people are born with large or small trees, their size could also be affected by trauma, such as a head injury, during a person's life. The team is now working on discovering how the excess, compensatory dopamine produced large trees attack the nervous system. If the branching theory is proved correct, there are already drugs that could arrest the branching of the tree early in a person's life, Professor Horne said, and thwart the onset of Parkinson's. "If we were able to detect in someone of 20 that they have Parkinson's disease but the symptoms had not yet begun to show, we can start to treat them," Professor Horne said. SOURCE: The Age, Australia http://www.theage.com.au/articles/2003/08/17/1061059717785.html * * * ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn