title: Vascular risk moderates associations between hippocampal subfield volumes and memory.
abstract: Advanced age and vascular risk negatively affect episodic memory. The hippocampus (HC) is a complex structure, and little is known about the roles of different HC regions in age-related memory declines. Using data from an ongoing longitudinal study, we investigated whether memory functions are related to volumes of specific HC subregions (CA1-2, CA3-4/dentate gyrus, and subiculum). Furthermore, we inquired if arterial hypertension, a common age-related vascular risk factor, modifies age-related differences in HC regional volumes, concurrent memory performance, and improvement in memory over multiple administrations. Healthy adults (n = 49, 52-82 years old) completed associative recognition and free recall tasks. In grouped path models, covariance structures differed between hypertensive and normotensive participants. Whereas larger CA3-4/dentate gyrus volumes predicted greater improvement in associative memory over repeated tests regardless of vascular risk, CA1-2 volumes were associated with improvement in noun recall only in hypertensive participants. Only among hypertensive participants, CA1-2 volumes negatively related to age and CA3-4/dentate gyrus and CA1-2 volumes were associated with performance at the last measurement occasion. These findings suggest that relatively small regions of the HC may play a role in age-related memory declines and that vascular risk factors associated with advanced age may modify that relationship.
authors.affiliation: Wayne State University, Detroit, MI.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Bender
authors.forename: Ana M
authors.initials: AM
authors.lastname: Daugherty
authors.forename: Naftali
authors.initials: N
authors.lastname: Raz
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000523:psychology; D001794:Blood Pressure / Q000502:physiology; D056547:CA1 Region, Hippocampal / Q000033:anatomy & histology / Q000502:physiology; D056651:CA2 Region, Hippocampal / Q000033:anatomy & histology / Q000502:physiology; D056654:CA3 Region, Hippocampal / Q000033:anatomy & histology / Q000502:physiology; D018891:Dentate Gyrus / Q000502:physiology; D018728:Entorhinal Cortex / Q000502:physiology; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology; D021641:Recognition, Psychology / Q000502:physiology; D012307:Risk Factors; D014652:Vascular Diseases / Q000503:physiopathology*