In experiments on rats, it turned out that neurons involved with Parkinson's switched on paths responsible for increasing or decreasing motion. It's the first time science has shown that a given neuron type can form distinctive brain circuits with different results, according to researcher Jin Hyung Lee.

The discoveries made here could lead to better treatments for Parkinson's. For example, doctors already use deep brain stimulation to reduce tremors -- this could lead to more effective stimulation by targeting the neurons most likely to produce results. And in the long run, this could shed light on many neurological conditions where the involved brain processes aren't always clear.