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Morning Edition, November 17, 2008 · There is growing evidence that small clusters of a protein called amyloid beta are what cause brain damage in Alzheimer's disease.

Scientists at the annual meeting of the Society for Neuroscience in Washington, D.C., say clusters of just two or three amyloid beta protein molecules can damage synapses, the connections between brain cells.

New research also shows that plaques of amyloid beta — much larger groupings made up of millions of cells — are not nearly as harmful as the small clusters.

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