An exciting discovery via ScienceDaily: researchers "have discovered the key brain chemical that causes Parkinson's disease ... Parkinson's disease occurs when some nerve cells in a part of the brain called the substantia nigra die or become impaired. Normally, these cells produce dopamine - a vital chemical that allows smooth, coordinated function of the body's muscles and movements. Scientists have long known that a key protein called alpha-synuclein plays a role in the development of Parkinson's disease. Alpha-synuclein is found throughout the brain - but in some people, the protein clumps together. This causes the death of the dopamine-producing cells, which in turn causes Parkinson's to develop. ... researchers discovered that dopamine itself actually plays a role in destroying the cells that produce it. In the process that leads to Parkinson's disease, dopamine is converted into a highly toxic chemical called DOPAL. Using test-tube, cell-culture and animal models, the researchers found that it is DOPAL that causes alpha-synuclein protein in the brain to clump together, which in turn triggers the death of dopamine-producing cells and leads to Parkinson's." It should go without saying that finding a key mechanism in this day and age will quickly lead into the design of therapies.