Link Between Early Protein Deposition And Alzheimer's Disease Identified

by Karishma Abhishek on Jan 26 2021 3:32 PM

Link Between Early Protein Deposition And Alzheimer`s Disease Identified
Initial deposition of tau proteins in the brainstem that is associated with neurophysiological processes specific to the early stages of Alzheimer's disease is demonstrated for the first time in humans by a study conducted at GIGA CRC In vivo Imaging laboratory, ULiège.
Alzheimer's disease (AD) is a neurodegenerative disease that leads to gradual memory loss and behavioral changes. It is characterized by the formation of beta-amyloid plaques and the tau proteins in the brain tissues, long before the actual symptoms occur (pre-clinical stages).

Thus the cortex presents a state of transient hyperexcitability during this early stage of the disease. And this mechanism remains poorly understood in humans due to technological limitations in the precise quantification of early protein deposition.

Healthy individuals aged between 50 and 70 years old were studied for the first deposits of tau and beta-amyloid proteins and its link to a higher level of cortical excitability neuroimaging methodologies (magnetic resonance imaging & positron emission tomography).

The cortical excitability of the participants was also measured using a non-invasive transcranial magnetic stimulation technique in conjunction with the acquisition of electroencephalographic recordings.

Alzheimer's Disease Impact on Brain Function

"The results of this study show that an increased amount of tau protein in the brainstem - its primary site of agglomeration - is specifically associated with a higher level of cortical excitability, while the researchers did not observe a significant relationship for the amount of beta-amyloid protein in the upper cortical areas. These results constitute a first in vivo observation in humans of the early link between proteins linked to Alzheimer's disease and their impact on brain function," says Maxime Van Egroo, scientific collaborator at the CRC In Vivo Imaging and first author of the scientific article.

The study thereby highlights that measuring the hyperexcitability of the cortex could be a useful marker to provide information on the progress of certain cerebral pathological processes linked to Alzheimer's disease. This may contribute to the early diagnosis even before the cognitive symptoms appear.