The formation of amyloid plaques in the brain is a hallmark of Alzheimer’s disease. But drugs designed to reduce accumulations of these plaques have so far yielded, at best, mixed results in clinical trials.
Yale researchers have found, however, that swelling caused by a byproduct of these plaques may be the true cause of the disease’s debilitating symptoms, they report Nov. 30 in the journal Nature. And they identified a biomarker that may help physicians better diagnose Alzheimer’s and provide a target for future therapies.
According to their findings, each formation of plaque can cause an accumulation of spheroid-shaped swellings along hundreds of axons — the thin cellular wires that connect the brain’s neurons — near amyloid plaque deposits. The swellings are caused by the gradual accumulation of organelles within cells known as lysosomes, which are known to digest cellular waste, researchers found. As the swellings enlarge, researchers say, they can blunt the transmission of normal electrical signals from one region of the brain to another.
