Majority of Alzheimer's plaques cleared from brains of living mice

Harvard Medical School researchers, working with scientists at Elan Pharmaceuticals, cleared 70 percent of Alzheimer's plaques from the brains of mice by applying anti-plaque antibodies directly to the mouse brains through tiny holes in their skulls. A year and a half before, Elan scientists showed that they could prevent plaque formation in the Alzheimer's-prone mice by vaccinating them with a protein found in the plaques, amyloid-beta. But this was the first time that anyone was able to clear pre-existing plaques from the brains of living animals. "No one has ever demonstrated directly the clearance of amyloid-beta deposits," said Brian Bacskai, Harvard Medical School instructor in neurology at Massachusetts General Hospital and lead author of the study. "It was especially surprising because it was so rapid. It really took only a few days for what looks to be almost complete clearance of amyloid-beta deposits."