Gu Li-Hua, Chen Jiu, Gao Li-Juan, Shu Hao, Wang Zan, Liu Duan, Yan Yan-Na, Li Shi-Jiang, Zhang Zhi-Jun
Department of Neurology, Affiliated ZhongDa Hospital, School of Medicine, Southeast UniversityNanjing, China.
Department of Psychology, Xinxiang Medical UniversityXinxiang, China.
Front Aging Neurosci. 2017 May 17;9:145. doi: 10.3389/fnagi.2017.00145. eCollection 2017.
Apolipoprotein E (APOE) ε4 is the only established risk gene for late-onset, sporadic Alzheimer's disease (AD). Previous studies have provided inconsistent evidence for the effect of APOE ε4 status on the visuospatial working memory (VSWM). The aim was to investigate the effect of APOE ε4 on VSWM with an event-related potential (ERP) study in healthy controls (HC) and amnestic mild cognitive impairment (aMCI) patients. The study recorded 39 aMCI patients (27 APOE ε4 non-carriers and 12 APOE ε4 carriers) and their 43 matched controls (25 APOE ε4 non-carriers and 18 APOE ε4 carriers) with an 64-channel electroencephalogram. Participants performed an N-back task, a VSWM paradigm that manipulated the number of items to be stored in memory. The present study detected reduced accuracy and delayed mean correct response time (RT) in aMCI patients compared to HC. P300, a positive component that peaks between 300 and 500 ms, was elicited by the VSWM task. In addition, aMCI patients showed decreased P300 amplitude at the central-parietal (CP1, CPz, and CP2) and parietal (P1, Pz, and P2) electrodes in 0- and 1-back task compared to HC. In both HC and aMCI patients, APOE ε4 carriers showed reduced P300 amplitude with respect to non-carriers, whereas no significant differences in accuracy or RT were detected between APOE ε4 carriers and non-carriers. Additionally, standardized low-resolution brain electromagnetic tomography analysis (s-LORETA) showed enhanced brain activation in the right parahippocampal gyrus (PHG) during P300 time range in APOE ε4 carriers with respect to non-carriers in aMCI patients. It demonstrated that P300 amplitude could predict VSWM deficits in aMCI patients and contribute to early detection of VSWM deficits in APOE ε4 carriers.
载脂蛋白E（APOE）ε4是晚发性散发性阿尔茨海默病（AD）唯一已确定的风险基因。先前的研究对于APOE ε4状态对视空间工作记忆（VSWM）的影响提供了不一致的证据。本研究旨在通过一项事件相关电位（ERP）研究，在健康对照（HC）和遗忘型轻度认知障碍（aMCI）患者中探究APOE ε4对VSWM的影响。该研究使用64导脑电图记录了39例aMCI患者（27例APOE ε4非携带者和12例APOE ε4携带者）及其43例匹配的对照（25例APOE ε4非携带者和18例APOE ε4携带者）。参与者执行了N-回溯任务，这是一种VSWM范式，可操纵要存储在记忆中的项目数量。本研究检测到，与HC相比，aMCI患者的准确性降低，平均正确反应时间（RT）延迟。VSWM任务诱发了P300，这是一个在300至500毫秒之间达到峰值的正向成分。此外，与HC相比，aMCI患者在0-和1-回溯任务中，中央顶叶（CP1、CPz和CP2）和顶叶（P1、Pz和P2）电极处的P300波幅降低。在HC和aMCI患者中，APOE ε4携带者相对于非携带者的P300波幅均降低，而在APOE ε4携带者和非携带者之间未检测到准确性或RT的显著差异。此外，标准化低分辨率脑电磁断层扫描分析（s-LORETA）显示，在aMCI患者中，APOE ε4携带者在P300时间范围内右侧海马旁回（PHG）的脑激活相对于非携带者增强。研究表明，P300波幅可预测aMCI患者的VSWM缺陷，并有助于早期检测APOE ε4携带者的VSWM缺陷。
