The findings showed that turning up brain cell firing rates drove up levels of amyloid beta in the spaces between brain cells. Corresponding drops in amyloid beta levels occurred when brain cells' ability to send messages was dampened or blocked completely.

The results, produced in mouse models of Alzheimer's, will appear in the journal Neuron on Dec. 22. They complement a Washington University study published earlier this year that used functional brain imaging to show that the brain areas that develop Alzheimer's plaques are also the regions that are the most active in healthy young people who are daydreaming or not carrying out a specific cognitive task (http://news-info.wustl.edu/news/page/normal/5621.html).

The two papers have researchers considering the possibility of someday slowing or preventing the development of Alzheimer's disease by using pharmaceuticals to selectively reduce some communication between brain cells. However, researchers still have to determine if increased levels of amyloid beta can be partially linked to particular classes of the nerve cell messengers and receptors that cells use to communicate with each other.

"Ideally, we will be hoping to find a drug or mechanism that could very specifically target the processes that lead to increased amyloid beta levels," says lead author John Cirrito, Ph.D., a postdoctoral research associate in neurology and psychology. "If we can identify these and find ways to modulate them, we'd have new ways of intervening in Alzheimer's disease."

Senior author David Holtzman, M.D., the Andrew B. and Gretchen P. Jones Professor and head of the Department of Neurology, says that the results do not contradict earli
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Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
21-Dec-2005