Specificity of brain activation patterns in people at genetic risk for Alzheimer disease
Specificity of brain activation patterns in people at genetic risk for Alzheimer disease
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DOI：
10.1176/appi.ajgp.10.1.44
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发表时间：
2002-01-01
影响因子：
7.2
通讯作者：
Bookheimer, SY
中科院分区：
文献类型：
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作者：
Burggren, AC;Small, GW;Bookheimer, SY
先前的正电子发射断层扫描（PET）和功能性磁共振成像（fMRI）研究表明，APOE ε 4等位基因携带者和那些没有患阿尔茨海默病（AD）风险的人之间的神经代谢和活动存在差异。携带64等位基因的非痴呆症患者在记忆所需区域的大脑激活程度和范围比非携带者更大，这表明他们进行了额外的认知工作来完成相同的任务。为了确定fMRI的差异是特定于记忆任务还是可推广到任何困难的认知任务，作者进行了fMRI，并比较了25名携带和不携带APOE 0等位基因的受试者的图像。在最困难的条件下，所有受试者的前额叶皮层的MR信号都有所增加，这表明认知努力有所增加。然而，这两个基因组的激活模式没有差异，即使在最困难的任务水平，这表明额外的认知努力的人在遗传风险的AD是特定的情节编码，而不仅仅是任务难度的反映。
Previous studies with positron-emission tomography (PET) and functional magnetic resonance imaging (fMRI) have indicated differences in neural metabolism and activity between carriers of the APOE epsilon4 allele and those who are not at risk for Alzheimer disease (AD). Persons without dementia carrying the 64 allele showed greater magnitude and extent of brain activation than noncarriers in regions required for memory, suggesting they performed additional cognitive work to accomplish the same task. To determine whether the fMRI differences were specific to a memory task or generalizable to any difficult cognitive task, the authors performed fMRI and compared images from 25 subjects with and without the APOE 0 allele. In the most difficult conditions, all subjects showed increased MR signal in the prefrontal cortex, indicating increased cognitive effort. However, the two genetic groups showed no differences in activation patterns even at the most difficult task level, suggesting that additional cognitive effort in persons at genetic risk for AD is specific to episodic encoding and is not merely a reflection of task difficulty.