Researchers have identified two groups of neurons that can be turned on and off to alleviate the movement-related symptoms of Parkinson's disease. The activation of these cells in the basal ganglia relieves symptoms for much longer than current therapies, like deep brain stimulation and pharmaceuticals. The study, completed in a mouse model of Parkinson's, used optogenetics to better understand the neural circuitry involved in Parkinson's disease, and could provide the basis for new experimental treatment protocols.