Brain cell activity increases levels of key ingredient in Alzheimer...( y of injected compounds to turn nerve c...),Health

Through a series of these experiments, researchers linked increased amyloid beta levels to the release of synaptic vesicles, small packets containing chemical messengers known as neurotransmitters. The primary way nerve cells send messages to each other is to release the vesicles waiting at the synapse, a structure where the arms of two nerve cells almost touch. The neurotransmitters cross the synapse and bind to receptors on the surface of the receiving nerve cell. Normal brain physiology produces amyloid beta and naturally clears it from the brain, so Cirrito conducted a series of follow-up experiments to try to get a sense for whether increased synaptic vesicle release was affecting amyloid beta production or clearance.

"It's probably not clearance, and the effect on production is probably pretty small," he says. "Instead, it appears that synaptic activity is regulating the amount of amyloid beta that gets released from inside brain cells, where amyloid beta is produced. We're going to follow up with studies of whether particular neurotransmitters can be linked to changes in amyloid beta levels."

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Contact: Michael C. Purdy
purdym@wustl.edu
314-286-0122
Washington University School of Medicine
21-Dec-2005