I thought it is a new thing which identifies and genetically marks the exact brain circuits (cells?) which control movements and developing the abilty to control them by laser light.
What cought my attention is the claim that the treatment does not involve dopamin in any way and thought it seems to be an attempt outside the "dopamin box".

I think the following article provides some additional clarification:

http://www.sciencedaily.com/releases...0707131357.htm

"We found that by activating the 'stop' pathway we could mimic Parkinson's disease. But what we really wanted was a strategy to treat the disease symptoms." For this, Dr. Kreitzer and colleagues turned to the "go" pathway. "We thought that by activating the 'go' pathway, we could re-balance these brain pathways and directly restore movement, even in the absence of dopamine." The strategy worked even better than expected. "We generated mice that lacked dopamine, and these mice showed many of the same symptoms found in humans with Parkinson's disease. But when we activated the 'go' pathway in these mice, they began to move around normally again. We restored all of their motor deficits with this treatment, even though the mice still lacked dopamine."

Imad