Among the afflictions of old age, Alzheimer's is a particular affront. The degenerative mental condition, which affects some 2 million people in the U.S., robs its victims of their dignity and renders them helpless. They become confused, lose track of time and are eventually unable to recognize spouses and other loved ones. Physiologically, Alzheimer's manifests itself in the form of abnormal protein deposits in the brain. But the reason these insidious tangles and plaques build up remains unknown.
Last week an international team led by scientists at Massachusetts General Hospital and the National Institutes of Health announced in the journal Science...