Functional connectivity of the hippocampus in elderly with mild memory dysfunction carrying the APOE epsilon4 allele.
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.
Bartrés-Faz
David
D
Departament de Psiquiatria i Psicobiologia Clínica, Fac. Medicina, Universitat de Barcelona, C/Casanova 143, 08036 Barcelona, Spain.
Serra-Grabulosa
Josep M
JM
Sun
Felice T
FT
Solé-Padullés
Cristina
C
Rami
Lorena
L
Molinuevo
José L
JL
Bosch
Beatriu
B
Mercader
Josep M
JM
Bargalló
Núria
N
Falcón
Carles
C
Vendrell
Pere
P
Junqué
Carme
C
D'Esposito
Mark
M
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*
D053318:Apolipoprotein E3