Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neuropsychology, Leipzig, 04103, Leipzig, Germany
Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neuropsychology, Leipzig, 04103, Leipzig, Germany.
J Neurosci. 2014 Jul 9;34(28):9202-12. doi: 10.1523/JNEUROSCI.0228-14.2014.
Despite myriads of studies on a parallel organization of cortico-striatal-thalamo-cortical loops, direct evidence of this has been lacking for the healthy human brain. Here, we scrutinize the functional specificity of the cortico-subcortical loops depending on varying levels of cognitive hierarchy as well as their structural connectivity with high-resolution fMRI and diffusion-weighted MRI (dMRI) at 7 tesla. Three levels of cognitive hierarchy were implemented in two domains: second language and nonlanguage. In fMRI, for the higher level, activations were found in the ventroanterior portion of the prefrontal cortex (PFC), the head of the caudate nucleus (CN), and the ventral anterior nucleus (VA) in the thalamus. Conversely, for the lower level, activations were located in the posterior region of the PFC, the body of the CN, and the medial dorsal nucleus (MD) in the thalamus. This gradient pattern of activations was furthermore shown to be tenable by the parallel connectivity in dMRI tractography connecting the anterior regions of the PFC with the head of the CN and the VA in the thalamus, whereas the posterior activations of the PFC were linked to the body of the CN and the MD in the thalamus. This is the first human in vivo study combining fMRI and dMRI showing that the functional specificity is mirrored within the cortico-subcortical loop substantiated by parallel networks.
尽管有无数关于皮质-纹状体-丘脑-皮质回路的平行组织的研究，但对于健康的人类大脑，一直缺乏直接的证据。在这里，我们通过在 7 特斯拉下使用高分辨率 fMRI 和扩散加权 MRI（dMRI），仔细研究了皮质-皮质下回路的功能特异性，以及它们与认知层次的不同水平的结构连接。在两个领域中实施了三个认知层次：第二语言和非语言。在 fMRI 中，对于较高层次，在前额叶皮层（PFC）的腹前部分、尾状核头部（CN）和丘脑腹前核（VA）中发现了激活。相反，对于较低层次，激活位于 PFC 的后区、CN 的体部和丘脑的内侧背核（MD）中。这种激活的梯度模式通过 dMRI 轨迹连接 PFC 的前区与 CN 的头部和丘脑的 VA 的平行连接来证明是可行的，而 PFC 的后区则与 CN 的体部和丘脑的 MD 相连。这是第一个结合 fMRI 和 dMRI 的人类体内研究，表明功能特异性通过平行网络在皮质-皮质下回路中得到反映。
