A brain circuit tied to emotion may lead to better treatments for Parkinson's disease

Paul knew his young grandson was in danger.

"Out of the corner of my eye I could see this little figure moving," he says. The figure was heading for a steep flight of stairs.

But what could he do? Paul was sitting down. And after more than a decade of living with Parkinson's disease, getting out of a chair had become a long and arduous process.

But not on this day.

"Paul jumped up from the chair and ran to my grandson," says his wife, Rose. (The couple asked to be identified by only their first names to protect their medical privacy.) "I mean, he just got up like there was nothing and ran to pick up Max."

Amazing. But it's also the kind of story that's become familiar to , professor and chair of neurobiology at the University of Pittsburgh and scientific director of the University of Pittsburgh Brain Institute.