Abnormal cortical networks in mild cognitive impairment and Alzheimer's disease.
Abnormal cortical networks in mild cognitive impairment and Alzheimer's disease.
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DOI：
10.1371/journal.pcbi.1001006
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发表时间：
2010-11-18
影响因子：
4.3
通讯作者：
Alzheimer's Disease Neuroimaging Initiative
中科院分区：
文献类型：
--
作者：
Yao Z;Zhang Y;Lin L;Zhou Y;Xu C;Jiang T;Alzheimer's Disease Neuroimaging Initiative
最近，许多研究人员利用图论研究阿尔茨海默病（AD）中异常的大脑结构，并取得了很大进展。然而，轻度认知障碍（MCI）中皮质网络的特征在很大程度上仍未被探索。在这项研究中，利用自动解剖标记（AAL）模板将从磁共振成像（MRI）获得的除小脑外所有脑区的灰质体积划分成90个区域，以构建98名正常对照（NCs）、113名MCI患者和91名AD患者的皮质网络。分别计算了三组中每组的网络属性指标。我们发现所有三个皮质网络都呈现出小世界特性，并且在双侧同源区域之间存在很强的半球间相关性。在这三个皮质网络中，我们发现AD患者的聚类系数最大，绝对路径长度最长，这可能表明AD患者的皮质网络组织最不理想。MCI网络的小世界指标呈现中间值。鉴于MCI被认为是正常衰老和AD之间的过渡阶段，这一发现是合理的。在聚类系数和绝对路径长度的所有组间差异中，只有AD组和正常对照组之间的差异具有统计学意义。与正常对照组相比，MCI组和AD组在额叶保留了其枢纽区域，但在颞叶出现了枢纽区域的缺失。此外，在MCI组和AD组中，在海马旁回、内侧颞叶、扣带回、梭状回、内侧额叶和眶额回检测到区域间相关性的改变。与先前关于功能连接性的研究类似，我们还发现MCI组和AD组在局部脑叶内区域间相关性增加，远距离区域间相关性被破坏。
了解阿尔茨海默病（AD）的进展至关重要。我们研究了从正常到AD连续过程中的皮质连接网络。轻度认知障碍（MCI）被认为是正常衰老和AD之间的过渡阶段。通过研究这三个阶段（正常、MCI和AD）皮质网络的特征，我们发现所有三个网络都呈现出小世界特性。这些特性表明人脑中信息的高效传递。我们还发现MCI网络的小世界指标介于正常对照组和AD患者之间。这支持了MCI是正常衰老和AD之间过渡阶段的观点。此外，我们发现MCI患者和AD患者区域间相关性发生改变，这可能表明一种补偿系统与脑萎缩相互作用。MCI患者和AD患者中补偿机制的存在可能使他们能够利用额外的认知资源在更接近正常的水平上发挥功能。未来，我们需要整合通过不同尺度的各种功能和解剖脑成像技术获得的多层次网络特征，以了解MCI和AD的病理生理机制。我们提出脑网络组学来代表这种整合框架。
Recently, many researchers have used graph theory to study the aberrant brain structures in Alzheimer's disease (AD) and have made great progress. However, the characteristics of the cortical network in Mild Cognitive Impairment (MCI) are still largely unexplored. In this study, the gray matter volumes obtained from magnetic resonance imaging (MRI) for all brain regions except the cerebellum were parcellated into 90 areas using the automated anatomical labeling (AAL) template to construct cortical networks for 98 normal controls (NCs), 113 MCIs and 91 ADs. The measurements of the network properties were calculated for each of the three groups respectively. We found that all three cortical networks exhibited small-world properties and those strong interhemispheric correlations existed between bilaterally homologous regions. Among the three cortical networks, we found the greatest clustering coefficient and the longest absolute path length in AD, which might indicate that the organization of the cortical network was the least optimal in AD. The small-world measures of the MCI network exhibited intermediate values. This finding is logical given that MCI is considered to be the transitional stage between normal aging and AD. Out of all the between-group differences in the clustering coefficient and absolute path length, only the differences between the AD and normal control groups were statistically significant. Compared with the normal controls, the MCI and AD groups retained their hub regions in the frontal lobe but showed a loss of hub regions in the temporal lobe. In addition, altered interregional correlations were detected in the parahippocampus gyrus, medial temporal lobe, cingulum, fusiform, medial frontal lobe, and orbital frontal gyrus in groups with MCI and AD. Similar to previous studies of functional connectivity, we also revealed increased interregional correlations within the local brain lobes and disrupted long distance interregional correlations in groups with MCI and AD. Understanding the progression of Alzheimer's disease (AD) is essential. We investigated networks of cortical connectivity along a continuum from normal to AD. Mild Cognitive Impairment (MCI) has been implicated as transitional between normal aging and AD. By investigating the characteristics of cortical networks in these three stages (normal, MCI and AD), we found that all three networks exhibited small-world properties. These properties indicate efficient information transfer in the human brain. We also found that the small-world measures of the MCI network were intermediate to those of the normal controls and the patients with AD. This supports the opinion that MCI is a transitional stage between normal aging and AD. Additionally, we found altered interregional correlations in patients with MCI and AD, which may indicate that a compensatory system interacts with cerebral atrophy. The presence of compensatory mechanisms in patients with MCI and AD may enable them to use additional cognitive resources to function on a more nearly normal level. In future, we need to integrate the multi-level network features obtained with various functional and anatomical brain imaging technologies on different scales to understand the pathophysiological mechanism of MCI and AD. We propose brainnetome to represent such integration framework.
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DOI：
10.1523/jneurosci.1929-08.2008
发表时间：
2008-09-10
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Bassett DS;Bullmore E;Verchinski BA;Mattay VS;Weinberger DR;Meyer-Lindenberg A
通讯作者：
Meyer-Lindenberg A
影响因子：
5.3
作者：
Achard, S;Salvador, R;Bullmore, ET
通讯作者：
Bullmore, ET
影响因子：
4.3
作者：
Achard S;Bullmore E
通讯作者：
Bullmore E
DOI：
10.1016/s0006-291x(84)80190-4
发表时间：
1984-01-01
影响因子：
3.1
作者：
GLENNER, GG;WONG, CW
通讯作者：
WONG, CW
影响因子：
14.5
作者：
Bokde, ALW;Lopez-Bayo, P;Hampel, H
通讯作者：
Hampel, H