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The dementia and loss of mental faculties resulting from Alzheimer's disease has long been recognized, but the exact cause has remained elusive, until perhaps now.
New research suggests that one form of beta-amyloid protein - which clumps around an afflicted brain's neurons and forms plaque that inhibits and destroys neurons needed for daily functions and memories - causes symptoms of Alzheimer's.
Previous research had been unable to determine whether the beta-amyloid plaque was a cause or a side effect of Alzheimer's disease.
In the new study, researchers caused Alzheimer's symptoms of impaired memory function in rats by injecting them with a two-molecule soluble form of beta-amyloid protein.
One-molecule and three-molecule forms of both soluble and insoluble proteins did not trigger illness in the rats, which researchers say may explain why some people with beta-amyloid plaque don't exhibit such symptoms.