Regional differences in cerebral asymmetries of human cortical white matter
Regional differences in cerebral asymmetries of human cortical white matter
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DOI：
10.1016/j.neuropsychologia.2011.09.011
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发表时间：
2011-11-01
期刊：
影响因子：
2.6
通讯作者：
Kirk, Ian J.
中科院分区：
文献类型：
--
作者：
Iwabuchi, Sarina J.;Haeberling, Isabelle S.;Kirk, Ian J.
大脑半球的结构不对称的形式，支持公认的功能不对称，还没有得到很好的理解。虽然，许多以前的研究已经调查了与强功能不对称相关的区域的结构差异，例如语言过程，但功能不对称的大脑区域受到的关注较少。目前的研究旨在通过使用扩散张量成像（DTI）和纤维束成像探索健康人脑的全球白色物质不对称性来解决这一问题。对29名健康右利手男性进行了DTI，并使用概率纤维束成像重建了四个主要肺叶的通路。计算平均FA、平行和垂直扩散值，并对生成的每个通路进行半球间比较。在FA测量中发现顶叶（枕叶不对称）和枕叶（枕叶不对称）通路的显著不对称。然而，平行和/或垂直扩散的不对称模式，观察到在所有四个叶，甚至在对称FA的途径。例如，在顶叶和额叶中发现了平行扩散的显著不对称性，而在颞叶和枕叶中发现了显著不对称性。我们认为，这些不同的扩散不对称模式反映了显微解剖学的差异，支持已知的模式的差异功能不对称。不同方向的解剖学不对称性支持了这样一种观点，即可能有许多不同的侧化影响在大脑中起作用。(C)2011爱思唯尔有限公司版权所有。
The form of the structural asymmetries across the cerebral hemispheres, that support well-established functional asymmetries, are not well understood. Although, many previous studies have investigated structural differences in areas associated with strong functional asymmetries, such as language processes, regions of the brain with less well established functional laterality have received less attention. The current study aims to address this by exploring global white matter asymmetries of the healthy human brain using diffusion tensor imaging (DTI) and tractography. DTI was conducted on twenty-nine healthy right-handed males, and pathways from the four major lobes were reconstructed using probabilistic tractography. Mean FA, parallel and perpendicular diffusion values were calculated and compared across hemispheres for each pathway generated. Significant asymmetries in the parietal (rightward asymmetry) and occipital (leftward asymmetry) pathways were found in FA measures. However, asymmetric patterns in parallel and/or perpendicular diffusion were observed in all four lobes, even in pathways with symmetrical FA. For instance, significant rightward asymmetry in parallel diffusion was found in the parietal and frontal lobes, whereas significant leftward asymmetry was found in the temporal and occipital lobes. We suggest that these different patterns of diffusion asymmetry reflect differences in microanatomy that support the known patterns of differential functional asymmetry. The different directions of anatomical asymmetry support the notion that there may be a number of different lateralising influences operating in the brain. (C) 2011 Elsevier Ltd. All rights reserved.