Stanford scientists discover that by changing a mouse's neurons to respond to light, they could use fiber optic cables to influence the mouse to do certain things. The trick is to insert plant genes into the brain first.
The full story is over at Wired, and is quite interesting, but one of the effects achieved was to basically reverse Parkinson's disease in mice. You should head over to find more, including what they'll do to get around the need to thread fibre through your skull. [Wired]