Two proteins linked to Alzheimer’s disease begin disrupting brain activity before signs of memory loss, study says

Researchers at Massachusetts General Hospital have discovered that two proteins linked to Alzheimer’s disease begin disrupting brain activity before signs of cognitive impairment show in patients, a finding that could have implications for early detection of the debilitating neurological condition, according to a recent statement.

The statement, attributed to Mass. General, was posted Monday to the Harvard Gazette, the official news publication of Harvard University, which is affiliated with the hospital.

Findings from the research team, published in the Proceedings of the National Academy of Sciences, show the early accumulation of the amyloid-β and tau proteins start affecting neurological connections needed for memory “years before” the onset of cognitive impairment.

The statement said researchers have known for years that amyloid-β and tau can kill neurons, the brain’s most abundant cells, eventually leading to impairment and dementia.

“But we did not know how the brain’s connections respond to the accumulation of these proteins very early in the disease process, even before symptoms,” said Yakeel Quiroz, a senior author of the study who heads Mass. General’s Familial Dementia Neuroimaging Lab and Multicultural Alzheimer’s Prevention Program, in the statement.

The study, the statement said, examined “individuals from a large family of more than 6,000 living members with Alzheimer’s disease prevalence from Antioquia, Colombia, South America.”

The statement said researchers used functional magnetic resonance imaging, or fMRI, to examine regions of the brain at an area called the voxel level, to look at connectivity within and between the brain’s different networks.

“This discovery improves our understanding of how AD-related pathology alters the brain’s functional organization years before cognitive impairment occurs,” Quiroz said. “These findings are exciting because they also suggest that fMRI could be used in the future to identify people who may already have Alzheimer’s disease pathology in their brain and may develop dementia in the future, though more research is still needed.”

Material from prior Globe stories was used in this report.