Researchers have tracked down nerve cell circuits within the brain that controls body movement, thus paving the way for future cures of movement disorders like Parkinson’s disease.

The results of the study, published in the scientific journal, Nature, suggests that though scientists have identified and drawn up these circuits in the late 1990s and 1990s, there was no way to test their efficacy in the animal models.

The study was conducted by researchers at the Gladstone Institute of Neurological Disease (GIND) and Stanford University. The scientists have also established the function of these nerve cell circuits, says Anatol Kreitzer, who led the study group.

This research used genetic methods to allow mice to produce a light-sensitive protein in very select group of cells in the brain. A molecular "switch" from green algae called channelrhodopsin-2 (ChR2), which is turned on by blue light, was used to trace the neuronal signals. ChR2 was genetically engineered to suit specifically into cells in a mouse.

The scientists analyzed the signaling pathway using an optic fiber as big as a human hair that was inserted in the brain. When this optic fiber was illuminated through a laser source, it caused the ChR2 to become active.

The study reveals that selective stimulation of the motor planning circuitry may hold the key to treating Parkinson's disease and other disorders involving these circuits, such as Huntington's disease, Tourette's syndrome, obsessive-compulsive disorder, and addiction.

The GIND team collaborated with Stanford's Karl Deisseroth, creator of a light activation technology that enabled scientists to activate specific circuits in the motor regions of brain. Parkinson's is the second most common neurodegenerative disease after Alzheimer’s. Parkinson’s is caused due to a loss of the brain chemical dopamine resulting in tremor, rigidity (an increase in muscle tone), slowed movements, problems with posture, and difficulty walking.