Bartrés-Faz David, Serra-Grabulosa Josep M, Sun Felice T, Solé-Padullés Cristina, Rami Lorena, Molinuevo José L, Bosch Beatriu, Mercader Josep M, Bargalló Núria, Falcón Carles, Vendrell Pere, Junqué Carme, D'Esposito Mark
Departament de Psiquiatria i Psicobiologia Clínica, Fac. Medicina, Universitat de Barcelona, C/Casanova 143, 08036 Barcelona, Spain.
Neurobiol Aging. 2008 Nov;29(11):1644-53. doi: 10.1016/j.neurobiolaging.2007.04.021. Epub 2007 Jun 11.
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.
本研究的目的是，在一组有轻度记忆障碍的老年人中，基于是否存在载脂蛋白Eε4等位基因，评估功能性磁共振成像（fMRI）面孔-名字学习任务期间海马体的功能连接性。研究了12名ε4携带者和20名非携带者，他们均有轻度记忆功能障碍，且在整体认知功能和记忆的临床评估中表现相当。受试者接受了一次fMRI检查，其中包括一个面孔-名字编码记忆任务。扫描后，要求受试者将面孔与相应的名字配对。通过使用相干分析来测量海马体的功能连接性，以评估与记忆编码过程相关的脑回路活动。与非载脂蛋白Eε4等位基因携带者相比，载脂蛋白Eε4携带者与前扣带回、顶下小叶/中央后回区域和尾状核的连接性增强。在执行联想记忆任务期间，载脂蛋白Eε4等位基因携带者的海马体与其他脑区的连接性增强，这可能揭示了携带这种基因变异的受试者在记忆编码过程中，皮质-皮质下网络存在额外的活动。
