Functional MRI of mnemonic networks across the spectrum of normal aging, mild cognitive impairment, and Alzheimer's disease.
Functional MRI of mnemonic networks across the spectrum of normal aging, mild cognitive impairment, and Alzheimer's disease.
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DOI：
10.3233/jad-2012-120730
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Sperling RA
中科院分区：
文献类型：
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作者：
Chhatwal JP;Sperling RA
功能性磁共振成像（fMRI）是一种非侵入性技术，已普遍用于检查正常和受损认知状态下的神经网络功能。使用这种有前途的分析类型，研究人员已经确定了作为大规模神经网络运行的解剖学分布区域的存在，这些区域在联想记忆任务的执行过程中和静息状态下都可以观察到。将这些解剖学上不同的区域组装成功能集合，以及它们精心设计的激活和去激活，为复杂的行为（如联想记忆的形成和检索）奠定了基础。我们回顾了使用任务相关和无任务MRI来阐明正常老年人、轻度认知障碍（MCI）患者和阿尔茨海默病（AD）痴呆患者神经活动的变化，重点关注默认模式网络（DMN）和内侧颞叶（MTL）的活动改变。我们将无任务的fMRI研究置于更传统的、基于任务的人类记忆fMRI研究的更大背景中，这些研究已经牢固地确立了MTL在联想编码中的关键作用。最后，我们讨论了来自我们小组和其他人的数据，这些数据表明无任务MRI和基于任务的fMRI可能被证明是有用的非侵入性生物标志物，用于研究AD过程中记忆障碍的进展。
Functional magnetic resonance imaging (fMRI) is a non-invasive technique that has come into common use to examine neural network function in normal and impaired cognitive states. Using this promising type of analysis, researchers have identified the presence of anatomically distributed regions operating as large-scale neural networks, which are observed both during the performance of associative memory tasks and in the resting state. The assembly of these anatomically distinct regions into functional ensembles and their choreographed activation and deactivation sets the stage for complex behaviors such as the formation and retrieval of associative memories. We review progress in the use of task-related and task-free MRI to elucidate the changes in neural activity in normal older individuals, patients with mild cognitive impairment (MCI), and those with Alzheimer’s disease (AD) dementia, focusing on the altered activity of the default mode network (DMN) and medial temporal lobe (MTL). We place task-free fMRI studies into the larger context of more traditional, task-based fMRI studies of human memory, which have firmly established the critical role of the MTL in associative encoding. Lastly, we discuss the data from our group and others that suggests task-free MRI and task-based fMRI may prove useful as non-invasive biomarkers in studying the progression of memory failure over the course of AD.