The finding does have immediate relevance to the effort to develop treatments for Alzheimer's disease, Gandy said. "It reinforces the idea that anti-amyloid medication is a rational strategy," he said. "It reinforces the idea that attacking amyloid plaque helps nerve cells. You can see in nerve cells nearby changes in shape indicating that the cells are reacting to amyloid plaque, that is a link between those features of a pathology."
The study also answers a question about whether amyloid plaque can form only near blood vessels, Gandy said. "There have been reports that every amyloid plaque had a blood vessel somewhere," he explained. "That seems not to be the case."
But formation of amyloid plaque is not the only brain change associated with Alzheimer's disease, Hyman noted. Another notable feature consists of changes in the tau proteins that normally provide a scaffold for orderly function of nerve cells in the brain. Those tau proteins can become disordered, forming tangles that lead to destruction of nerve cells.
Studies of the formation of those tangles, using the same technology that led to the plaque discovery, are about to begin, Hyman said.
Keep up to date on Alzheimer's disease by consulting the Alzheimer's Association.
SOURCES: Bradley Hyman, M.D., Ph.D., director, Alzheimer's Unit, Massachusetts General Hospital, Boston; Sam Gandy, M.D., professor, Alzheimer's Disease Research, and associate director, Alzheimer's Disease Research Center, Mount Sinai Medical Center, New York City; Feb. 7, 2008, Nature
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