The human isocortex consists of tangentially organized layers with unique cytoarchitectural properties. These layers show spatial variations in thickness and cytoarchitecture across the neocortex, which is thought to support function through enabling targeted corticocortical connections. Here, leveraging maps of the 6 cortical layers based on 3D human brain histology, we aimed to quantitatively characterize the systematic covariation of laminar structure in the cortex and its functional consequences. After correcting for the effect of cortical curvature, we identified a spatial pattern of changes in laminar thickness covariance from lateral frontal to posterior occipital regions, which differentiated the dominance of infra- versus supragranular layer thickness. Corresponding to the laminar regularities of cortical connections along cortical hierarchy, the infragranular-dominant pattern of laminar thickness was associated with higher hierarchical positions of regions, mapped based on resting-state effective connectivity in humans and tract-tracing of structural connections in macaques. Moreover, we show that regions with similar laminar thickness patterns have a higher likelihood of structural connections and strength of functional connections. In sum, here we characterize the organization of laminar thickness in the human isocortex and its association with cortico-cortical connectivity, illustrating how laminar organization may provide a foundational principle of cortical function.

中文翻译：

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人类等皮质层状厚度的区域变化与皮质层次结构和区域间连接性有关。

人类等皮质由具有独特细胞结构特性的切向组织层组成。这些层显示出整个新皮质的厚度和细胞结构的空间变化，这被认为通过实现目标皮质连接来支持功能。在这里，我们利用基于 3D 人脑组织学的 6 个皮质层图，旨在定量表征皮质层状结构的系统协变及其功能后果。在校正皮质曲率的影响后，我们确定了从额叶外侧到后枕叶区域层状厚度协方差变化的空间模式，这区分了颗粒下层厚度与颗粒上层厚度的主导地位。与沿皮质层次结构的皮质连接的层状规律相对应，层状厚度的颗粒下主导模式与区域的较高层次位置相关，这是根据人类静息态有效连接和猕猴结构连接的束追踪绘制的。此外，我们表明具有相似层状厚度模式的区域具有更高的结构连接可能性和功能连接强度。总之，我们在这里描述了人类等皮质中层状厚度的组织及其与皮质-皮质连接的关联，说明层状组织如何提供皮质功能的基本原理。