Deng Fan, Jiang Xi, Zhu Dajiang, Zhang Tuo, Li Kaiming, Guo Lei, Liu Tianming
Cortical Architecture Imaging and Discovery Lab, Department of Computer Science and Bioimaging Research Center, The University of Georgia, Athens, GA, USA.
Brain Struct Funct. 2014 Jul;219(4):1473-91. doi: 10.1007/s00429-013-0581-z. Epub 2013 May 21.
Diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI) have been broadly used in the neuroimaging field to investigate the macro-scale fiber connection patterns in the cerebral cortex. Our recent analyses of DTI and HARDI data demonstrated that gyri are connected by denser, streamlined fibers than sulci are. Inspired by this finding and motivated by the fact that DTI-derived fibers provide the structural substrates for functional connectivity, we hypothesize that gyri are global functional connection centers and sulci are local functional units. To test this functional model of gyri and sulci, we examined the structural and functional connectivity among the landmarks on the selected gyral/sulcal areas in the frontal/parietal lobe and in the whole cerebral cortex via multimodal DTI and resting state fMRI (R-fMRI) datasets. Our results demonstrate that functional connectivity is strong among gyri, weak among sulci, and moderate between gyri and sulci. These results suggest that gyri are functional connection centers that exchange information among remote structurally connected gyri and neighboring sulci, while sulci communicate directly with their neighboring gyri and indirectly with other cortical regions through gyri. This functional model of gyri and sulci has been supported by a series of experiments, and provides novel perspectives on the functional architecture of the cerebral cortex.
扩散张量成像（DTI）和高角分辨率扩散成像（HARDI）已在神经成像领域广泛应用，以研究大脑皮层的宏观纤维连接模式。我们最近对DTI和HARDI数据的分析表明，脑回之间的连接纤维比脑沟之间的更密集、更流畅。受这一发现的启发，并鉴于DTI衍生的纤维为功能连接提供结构基础这一事实，我们假设脑回是全局功能连接中心，而脑沟是局部功能单元。为了验证这一脑回和脑沟的功能模型，我们通过多模态DTI和静息态功能磁共振成像（R-fMRI）数据集，研究了额叶/顶叶以及整个大脑皮层中选定脑回/脑沟区域的地标之间的结构和功能连接。我们的结果表明，脑回之间的功能连接很强，脑沟之间的功能连接较弱，脑回和脑沟之间的功能连接适中。这些结果表明，脑回是功能连接中心，在结构上相连的远程脑回和相邻脑沟之间交换信息，而脑沟直接与其相邻脑回通信，并通过脑回与其他皮质区域间接通信。这一脑回和脑沟的功能模型得到了一系列实验的支持，并为大脑皮层的功能结构提供了新的视角。
