Trivedi, M., T. Schmitz, M. Ries, B. Torgerson, M. Sager, B. Hermann, S. Asthana, and S. Johnson. “Reduced Hippocampal Activation During Episodic Encoding in Middle-Aged Individuals at Genetic Risk of Alzheimer’s Disease: A Cross-Sectional Study.”. BMC Medicine, Vol. 4, 2006, p. 1.
The presence of the apolipoprotein E (APOE) epsilon4 allele is a major risk factor for the development of Alzheimer’s disease (AD), and has been associated with metabolic brain changes several years before the onset of typical AD symptoms. Functional MRI (fMRI) is a brain imaging technique that has been used to demonstrate hippocampal activation during measurement of episodic encoding, but the effect of the epsilon4 allele on hippocampal activation has not been firmly established.
PubMed: 16412236