title: Functional connectivity of the hippocampus in elderly with mild memory dysfunction carrying the APOE epsilon4 allele.
abstract: The purpose of the present study was to evaluate functional connectivity of the hippocampus during a fMRI face-name learning task in a group of elders with mild memory impairment on the basis of the presence or absence of the APOE epsilon4 allele. Twelve epsilon4 carriers and 20 non-carriers with mild memory dysfunction and exhibiting equivalent performance in clinical evaluations of global cognitive function and memory were studied. Subjects underwent a fMRI session consisting of a face-name encoding memory task. Following scanning, subjects were asked to pair faces with their corresponding proper name. Functional connectivity of the hippocampus was measured by using coherence analysis to evaluate the activity of brain circuits related to memory encoding processes. In contrast to non-APOE epsilon4 allele bearers, APOE epsilon4 carriers showed enhanced connectivity with the anterior cingulate, inferior parietal/postcentral gyrus region and the caudate nucleus. Enhanced hippocampal connectivity with additional brain regions in APOE epsilon4 allele carriers during the performance of an associative memory task may reveal the existence of additional activity in the cortico-subcortical network engaged during memory encoding in subjects carrying this genetic variant.
authors.affiliation: Departament de Psiquiatria i Psicobiologia Clínica, Fac. Medicina, Universitat de Barcelona, C/Casanova 143, 08036 Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Bartrés-Faz
authors.forename: Josep M
authors.initials: JM
authors.lastname: Serra-Grabulosa
authors.forename: Felice T
authors.initials: FT
authors.lastname: Sun
authors.forename: Cristina
authors.initials: C
authors.lastname: Solé-Padullés
authors.forename: Lorena
authors.initials: L
authors.lastname: Rami
authors.forename: José L
authors.initials: JL
authors.lastname: Molinuevo
authors.forename: Beatriu
authors.initials: B
authors.lastname: Bosch
authors.forename: Josep M
authors.initials: JM
authors.lastname: Mercader
authors.forename: Núria
authors.initials: N
authors.lastname: Bargalló
authors.forename: Carles
authors.initials: C
authors.lastname: Falcón
authors.forename: Pere
authors.initials: P
authors.lastname: Vendrell
authors.forename: Carme
authors.initials: C
authors.lastname: Junqué
authors.forename: Mark
authors.initials: M
authors.lastname: D'Esposito
mesh_terms: D000368:Aged; D053318:Apolipoprotein E3 / Q000235:genetics*; D001931:Brain Mapping; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006624:Hippocampus / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D008569:Memory Disorders / Q000235:genetics / Q000503:physiopathology*; D009415:Nerve Net / Q000503:physiopathology*
chemical_list: D053318:Apolipoprotein E3