The associations of the BDNF and APOE polymorphisms, hippocampal subfield volumes, and episodic memory performance across the lifespan.

Abstract

In this study, we explored the associations between the brain derived neurotrophic factor (BDNF) and the apolipoprotein E (APOE) polymorphisms and hippocampal subfields in 127 healthy participants (18-85 years). MRI datasets were collected on a 4.7 T system. Participants were administered the Wechsler Memory Scale to evaluate episodic memory function. Significant associations of both polymorphisms were present only in older adults (≥50 years). BDNF polymorphism was associated with larger dentate gyrus volumes within the anterior hippocampus (head) in Met-carriers compared to Val/Val homozygotes. We found that in Met-carriers total hippocampal volume predicted performance on visuospatial memory tasks. APOE polymorphism was associated with larger total hippocampal volume, especially in cornu ammonis 1-3 and subiculum in APOE ɛ2 carriers compared to both ɛ4 and ɛ3 carriers, while APOE ɛ3 and ɛ4 carriers did not differ from each other. APOE polymorphism was associated with better performance on visuospatial memory tasks in APOE ε2 carriers in comparison to ε4 carriers.