Functional magnetic resonance imaging and magnetoencephalography differences associated with APOEepsilon4 in young healthy adults.

Functional neural alterations are present in middle-aged to late-aged healthy individuals carrying the epsilon4 allele of the apolipoprotein E (APOEepsilon4) gene, a known risk factor for Alzheimer's disease. Neural activity was measured in young adults with and without the epsilon4 allele (APOEepsilon4+ and APOEepsilon4-) by functional magnetic resonance imaging and magnetoencephalography while performing a visual working memory task on two separate days. Greater activity was observed in frontal areas and cingulate gyri in APOEepsilon4+ participants by both functional magnetic resonance imaging and magnetoencephalography with regional blood oxygenation level-dependent responses correlating with increased theta band power. The findings suggest that the presence of the APOEepsilon4 allele has physiological consequences before aging that may contribute to risk for Alzheimer's disease.