Alzheimer’s breakthrough: research upends a long-held theory about what causes brain cells to die -which leads to cognitive decline – and could change how scientists design treatments

Toxic protein clusters associated with Alzheimer’s disease reach different regions of the brain early and then build up over decades, according to a new study

The research is the first to use human data to quantify the speed of molecular processes, and overturns a long-held theory derived from animal experiments

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The cause of Alzheimer’s progression in brain has been revealed in a new study – it goes against a long-held theory and could go on to affect how scientists design treatments. Photo: Shutterstock

Published: 12:07pm, 1 Nov 2021Updated: 8:16am, 2 Nov 2021

Toxic protein clusters that are thought to be responsible for the cognitive decline associated with Alzheimer’s disease reach different regions of the brain early and then build up over decades, according to a new study.

The research, published in Science Advances, is the first to use human data to quantify the speed of the molecular processes leading to the neurodegenerative condition, and could go on to affect how scientists design treatments.

It also upends a long-held theory that said the progression of Alzheimer’s was mainly caused by clusters spreading between different brain regions in a “chain reaction”, as has been found in mice and was thought true of people too.

“Two things came together that really made this work possible,” said Georg Meisl, a chemist at the University of Cambridge and the paper’s lead author. “One is very detailed data from PET [scans] and various different data sets we’ve put together, and the other thing is the mathematical models we’ve been developing over the past 10 years.”

The researchers used close to 400 postmortem brain samples from Alzheimer’s as well as 100 positron emission tomography (PET) scans from people living with the disease to track the build up of tau, one of two key proteins implicated in the condition.

In Alzheimer’s disease, tau and another protein called amyloid-beta build up into tangles and plaques – known together as aggregates – that cause brain cells to die and the brain to shrink.