title: Differential associations of age with volume and microstructure of hippocampal subfields in healthy older adults.
abstract: Hippocampal atrophy in advanced healthy aging has frequently been reported. However, the vulnerability of different hippocampal subfields to age-related atrophy is still a source of debate. Moreover, the association of age with the microstructural integrity of subfields is largely unknown. In this study, we investigated the associations between age and volume as well as microstructural integrity of hippocampal subfields using a three-dimensional (3D) surface mapping approach. Forty-three healthy older adults spanning the age range from 60 to 85 years underwent T1-weighted and diffusion-tensor imaging. Analyses demonstrated an association of age with hippocampal volume predominantly in the most anterior part of the hippocampal head, mainly corresponding to the subiculum. In contrast, the association of age with hippocampal microstructural integrity was mainly confined to regions located in the hippocampal body and tail, corresponding to the subiculum and CA1. Results indicate that age-related volumetric and microstructural alterations within hippocampal subfields provide complementary information and reflect different age-related processes. Potential mechanisms underlying the differential associations of age with volume and microstructure of hippocampal subfields are discussed.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Wolf
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany.
authors.forename: Florian U
authors.initials: FU
authors.lastname: Fischer
authors.affiliation: Inserm-EPHE, Université de Caen/Basse-Normandie, Caen, France.
authors.forename: Robin
authors.initials: R
authors.lastname: de Flores
authors.affiliation: Inserm-EPHE, Université de Caen/Basse-Normandie, Caen, France.
authors.forename: Gaël
authors.initials: G
authors.lastname: Chételat
authors.affiliation: Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Mainz, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fellgiebel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001931:Brain Mapping; D056547:CA1 Region, Hippocampal / Q000033:anatomy & histology / Q000254:growth & development; D056324:Diffusion Tensor Imaging; D005260:Female; D006624:Hippocampus / Q000033:anatomy & histology* / Q000254:growth & development*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged
keywords: CA1; diffusion-tensor imaging; healthy aging; hippocampal microstructure; hippocampal subfields; hippocampal volume; subiculum