http://www.cbc.ca/health/story/2009/...n-disease.html

It may take a combination of three molecules to kill brain cells in Parkinson's disease, researchers say.

The three molecules — the neurotransmitter dopamine, a calcium channel, and a protein called alpha-synuclein — act together, Eugene Mosharov of Columbia University Medical Center in New York and his colleagues said in Wednesday's online issue of the journal Neuron.

"Though the interactions among the three molecules are complex, the flip side is that we now see that there are many options available to rescue the cells," Mosharov said in a release.

Symptoms of Parkinson's include uncontrollable tremors and difficulty in moving arms and legs.

Scientists had suspected that three molecules were involved in killing neurons. The new findings suggest how it may happen.

Using a new electrochemical approach to growing neurons in the lab, the researchers were able to measure dopamine released outside the cells.

It's the location of dopamine that matters. Dopamine outside the cells, known as cytosolic dopamine, is toxic to neurons, the researchers found. If dopamine is confined inside cells, it's safe.