Amyloid-beta and tau proteins have been implicated in Alzheimer’s disease for a long time. The accumulation of these proteins causes damage and consequently the deterioration of mental capacity in the patients. Additional research and studies are necessary to understand how these proteins affect and deteriorate the condition.
A new study out from The Neuro labs by Sylvain Baillet and Douglas Research Centre’s Sylvia Villeneuve offers some clues into how these proteins influence brain activity and probably, therefore cognitive deterioration. This was unveiled in their paper titled “Synergistic association of Aβ and tau pathology with cortical neurophysiology and cognitive decline in asymptomatic older adults”, published in Nature Neuroscience 18th September 2024.
The team was led by Jonathan Gallego Rudolf, a Ph. D. candidate working with Baillet and Villeneuve, enlisted 104 participants that had the family history of Alzheimer. To ascertain the presence and position of the proteins, they performed positron emission tomography (PET) scans whereas magnetoencephalography (MEG) scans were used to capture the brain activity in these areas.
The scientists then made a comparison between the two scans They discovered that while amyloid scans rose in numerous regions believed to show macroscopic manifestation of brain hyperphosphorylated tau and hyperarousal brain, fast -frequency bandwidths expanded and slow- frequency ones shrugged.
As per the previous published work it was hypothesized by researchers that amyloid protein affects the hypoactivity. Higher concentration of these proteins slows brain activity.
The team for this trial took cognitive tests and found out that those patients who had higher degree of amyloid-tau protein, related to this brain slowing, recorded higher levels of decline in attention and memory.
This information implies that even though amyloid-beta and tau protein interact in the brain, and cause neurotoxicity, subjects presenting no symptoms of dementia show changes in the brain activity. In the second study, Rudolf intends to rescan the same subjects later to show that the increase of these two proteins enables the slowing down of brain function at a higher rate and to verify if this indicates the cognitive development of the participants accurately.
“In humans, our study offers initial evidence for the shift towards hypo-activity in the neurophysiological networks and the link between the network hypo-activity and the progressive cognitive decline over time. These outcomes are in line with the data obtained from animal and computational models, and the results enhance the knowledge of the pathological processes in the preclinical stage of Alzheimer’s disease.”
Reference:
McGill University. Understanding changes in preclinical Alzheimer’s disease: Study finds two proteins impact brain activity differently.
