Adults With Alzheimer’s Risk Factors Show Subtle Alterations in Brain Networks Despite Normal Cognition
Source | neurosciencenews.com
Summary: APOEe4, a gene associated with Alzheimer’s disease risk, doesn’t appear to directly affect memory performance or brain activity in older adults without cognitive impairment. However, the gene does seem to influence brain regions and systems that older at-risk adults activate to support successful memory recall.
Source: McGill University
Researchers at McGill University and the Douglas Mental Health University Institute, in collaboration with the StoP-AD Center, have published a new paper in the Journal of Alzheimer’s Disease, examining how a known genetic risk factor for late-onset Alzheimer’s disease (AD) influences memory and brain function in cognitively intact older adults with a family history of AD.
For their study, the researchers looked at a specific gene, called apolipoprotein E (APOE), which has three allelic variants: e2, e3 and e4. Of these genetic variants, previous studies have shown adults with a single APOE e4 (+APOEe4) gene are at higher risk of developing AD. In this study, Drs. Sheida Rabipour, Maria Natasha Rajah and collaborators used functional magnetic resonance imaging (fMRI) to explore whether having a +APOEe4 genotype altered brain activity during memory task performance in older adults who may be at risk of developing AD.
“It turns out that the +APOEe4 variant, most strongly associated with AD development, doesn’t directly affect memory performance or brain activity in cognitively intact older adults,” explains Dr. Rabipour, a postdoctoral researcher in the lab of Dr. Rajah, and the study’s first author. “Rather, +APOEe4 seems to influence the brain regions and systems that older at-risk adults activate to support successfully remembering past events.”