Frequency-Dependent Brain Regional Homogeneity Alterations in Patients with Mild Cognitive Impairment during Working Memory State Relative to Resting State.
Frequency-Dependent Brain Regional Homogeneity Alterations in Patients with Mild Cognitive Impairment during Working Memory State Relative to Resting State.
复制标题
轻度认知障碍患者在工作记忆状态相对于静息状态期间的频率依赖性大脑区域同质性变化
DOI：
10.3389/fnagi.2016.00060
复制
发表时间：
2016
影响因子：
4.8
通讯作者：
Li J
中科院分区：
文献类型：
--
作者：
Wang P;Li R;Yu J;Huang Z;Li J
几项研究报告了轻度认知障碍(MCI)患者的工作记忆缺陷。然而，以前研究MCI的神经机制的研究主要集中在工作记忆任务中大脑活动的变化。到目前为止，还没有研究比较MCI患者和正常对照组(NC)受试者工作记忆状态下大脑网络的变化。因此，我们使用区域同质性指数(REHO)来研究轻度认知障碍患者在工作记忆任务中相对于静息状态的脑网络损害，并在不同的频段识别出频率依赖性效应。结果表明，轻度认知障碍患者在慢波-3频段(0.073-0.198赫兹)的扣带回后部、右侧枕叶底部和部分右侧小脑、右侧丘脑、双侧额叶前皮质、左侧和右侧顶枕区的弥漫区，右角回位于Slow-5频段(0.01~0.027 Hz)。此外，在NCS中，在任务状态期间，属于默认模式网络(DMN)的集群中的ReHO值降低，而属于注意网络的集群中的ReHO值增加。然而，这种模式在MCI患者中是相反的，并与工作记忆性能下降有关。此外，我们还发现，在MCI患者中，上述区域与大脑其他部分的功能连接发生了变化。这是第一项比较MCI患者静息和工作记忆状态下ReHO频率依赖性变化的研究。这些结果为研究MCI患者工作记忆缺陷的神经机制提供了一个新的视角，并扩展了我们对静息和任务诱发状态下大脑模式变化的认识。
Several studies have reported working memory deficits in patients with mild cognitive impairment (MCI). However, previous studies investigating the neural mechanisms of MCI have primarily focused on brain activity alterations during working memory tasks. No study to date has compared brain network alterations in the working memory state between MCI patients and normal control (NC) subjects. Therefore, using the index of regional homogeneity (ReHo), we explored brain network impairments in MCI patients during a working memory task relative to the resting state, and identified frequency-dependent effects in separate frequency bands.Our results indicate that, in MCI patients, ReHo is altered in the posterior cingulate cortex (PCC) in the slow-3 band (0.073–0.198 Hz), and in the bottom of the right occipital lobe and part of the right cerebellum, the right thalamus, a diffusing region in the bilateral prefrontal cortex (PFC), the left and right parietal-occipital regions, and the right angular gyrus in the slow-5 band (0.01–0.027 Hz). Furthermore, in NCs, the value of ReHo in clusters belonging to the default mode network (DMN) decreased, while the value of ReHo in clusters belonging to the attentional network increased during the task state. However, this pattern was reversed in MCI patients, and was associated with decreased working memory performance. In addition, we identified altered functional connectivity of the abovementioned regions with other parts of the brain in MCI patients. This is the first study to compare frequency-dependent alterations of ReHo in MCI patients between resting and working memory states. The results provide a new perspective regarding the neural mechanisms of working memory deficits in MCI patients, and extend our knowledge of altered brain patterns in resting and task-evoked states.