Genetic topography of brain morphology
Genetic topography of brain morphology
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DOI：
10.1073/pnas.1308091110
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发表时间：
2013-10-15
影响因子：
11.1
通讯作者：
Kremen, William S.
中科院分区：
文献类型：
--
作者：
Chen, Chi-Hua;Fiecas, Mark;Kremen, William S.
动物数据显示，皮质发育最初是由主要沿着三个正交轴的遗传梯度决定的。我们之前利用成年双胞胎的神经成像数据，报道了沿前后轴的皮质表面积受遗传影响的差异。在这里，我们展示了在同一队列中，沿着背腹轴的皮质厚度的遗传影响的差异。在不同的结构和功能特性中，皮质组织中明显的垂直梯度现象可能起源于遗传梯度。大脑皮层模式的另一个新出现的主题是，遗传影响的模式概括了大脑半球内大脑皮层的空间地形。皮质厚度和表面积的遗传模式与皮质功能特化相对应。有趣的是，与遗传模式的广泛相似性相反，两组分析在基因上区分了皮质厚度和表面积。首先，遗传对皮质厚度和表面积的贡献很大程度上是不同的；它们之间的遗传相关性很小(即共同的遗传影响)。其次，遗传定义的区域之间的组织原则不同于厚度和表面积。对簇间遗传相似性矩阵结构的分析表明，尽管表面积簇与来自同一叶的簇表现出很大的遗传相似性，但厚度簇似乎与具有相似成熟时间的簇具有密切的遗传关系。这种差异与这两种特征在神经发育中遵循不同机制的证据是一致的。我们的发现突出了遗传对大脑皮层形态影响的复杂性，并提供了对大脑皮层遗传组织的新兴原理的一瞥。
Animal data show that cortical development is initially patterned by genetic gradients largely along three orthogonal axes. We previously reported differences in genetic influences on cortical surface area along an anterior-posterior axis using neuroimaging data of adult human twins. Here, we demonstrate differences in genetic influences on cortical thickness along a dorsal-ventral axis in the same cohort. The phenomenon of orthogonal gradations in cortical organization evident in different structural and functional properties may originate from genetic gradients. Another emerging theme of cortical patterning is that patterns of genetic influences recapitulate the spatial topography of the cortex within hemispheres. The genetic patterning of both cortical thickness and surface area corresponds to cortical functional specializations. Intriguingly, in contrast to broad similarities in genetic patterning, two sets of analyses distinguish cortical thickness and surface area genetically. First, genetic contributions to cortical thickness and surface area are largely distinct; there is very little genetic correlation (i.e., shared genetic influences) between them. Second, organizing principles among genetically defined regions differ between thickness and surface area. Examining the structure of the genetic similarity matrix among clusters revealed that, whereas surface area clusters showed great genetic proximity with clusters from the same lobe, thickness clusters appear to have close genetic relatedness with clusters that have similar maturational timing. The discrepancies are in line with evidence that the two traits follow different mechanisms in neurodevelopment. Our findings highlight the complexity of genetic influences on cortical morphology and provide a glimpse into emerging principles of genetic organization of the cortex.