How can fMRI help researchers study Alzheimer disease risk in APOE4 carriers?

Functional magnetic resonance imaging (fMRI) is a neuroimaging technique that detects changes in brain blood flow to map activity. In the context of Alzheimer disease, researchers use fMRI to study individuals who carry the APOE4 genetic variant, which is associated with an increased risk of late-onset disease.12

Studies have revealed that young APOE4 carriers (ages 20 to 35) often exhibit increased activity in the hippocampus, a region critical for memory and emotion. Scientists hypothesize that this early-life hippocampal hyperactivity may lead to subsequent dysfunction in the same region, ultimately contributing to the development of Alzheimer disease. Consequently, fMRI imaging in young APOE4 carriers serves as a potential tool for identifying those at the greatest risk for the disease.2