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Source: BELGIAN
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Clusters of toxic proteins, thought to be responsible for the cognitive decline in Alzheimer’s disease, don’t stay in one part of the brain. They reach different parts and accumulate there for decades, causing brain cells to die. That’s according to a new study published Friday.
The article, published in Science Advances, is the first to use human data to calculate the speed of molecular processes leading to Alzheimer’s. It could affect the way treatments are developed.
It disproves the theory that clusters form in one place and set off a chain reaction in other areas, a pattern seen in mice. Such spread may occur, but is not the primary factor, the researchers say.
400 brain samples
“Two things made this possible,” said Georg Meisl, a chemist at the University of Cambridge and one of the lead authors of the paper. “First, the study of very detailed data from PET scans and various data sets collected, and the mathematical models that have been developed over the last ten years.”
The researchers used 400 brain samples taken from deceased Alzheimer’s patients and 100 PET scans from people living with the disease to track the clumping of the tau protein. Tau and another protein, beta-amyloid, build up, causing brain cells to die and the brain to shrink.
That causes memory loss and an inability to perform everyday tasks. The disease affects more than 40 million people worldwide.
The researchers also found that it takes five years for the clumped proteins to double in number. That’s an “encouraging” figure, Meisl says, because it shows that nerve cells are able to fight these proteins. “Maybe if we can improve the cells a little bit, we can significantly delay the onset of the serious disease.”
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