Parkinson's disease appears to spread through the brain by means of a simple yet insidious mechanism, according to research published Friday by University of Pennsylvania scientists.


Like something out of a bad science-fiction movie, more healthy proteins latch onto the ones that have gone bad, adopting their "misfolded" configuration until deadly clumps build up in brain cell after brain cell, the Penn team found in its study of lab mice.

These clumps, known as Lewy bodies, were discovered long ago, but the authors - led by the prominent neurobiologist Virginia M.-Y. Lee, Ph.D. - say they now have hard evidence that the clumps play some sort of causal role in the disease.

What's more, the researchers are optimistic they can stop it in its tracks, because the bad proteins may be vulnerable as they travel from one cell to the next.

Scientists have suspected for years that a number of brain diseases follow this infectious-like path. But experts not involved with the new paper say it makes an especially strong case - at least with Parkinson's, which kills more than 20,000 people in the United States each year.

"This is, as far as I'm concerned, the most convincing evidence thus far that supports this hypothesis," said Robert Edwards, a professor of neurology at the University of California, San Francisco.

J. Paul Taylor, who studies brain diseases at St. Jude Children's Research Hospital in Tennessee, agreed with the Penn team that stopping the spread of the bad proteins seemed feasible, perhaps with a specially tailored antibody.

Indeed, Dr. Lee, who directs the Center for Neurodegenerative Disease Research at Penn's Perelman School of Medicine, said she and her colleagues are testing that idea in mice.

"We can catch the bad proteins as they go from one neuron to another," Dr. Lee said.

She cautioned that while the bad proteins seem to have an infectious quality within the brain, there is no evidence that Parkinson's can be passed from person to person.

Though there are drugs to ease the tremors and other symptoms of Parkinson's, it and the other neurodegenerative diseases have resisted efforts at a cure.