Functional Compartmentation and Connectivity of the Basal Ganglia at 9.4 Tesla

人脑的皮质下结构包括大量不同的核团，其占总脑体积的约25%。最大的核团聚集在基底神经节（BG）和丘脑（Th）中，它们都具有相对均匀的解剖结构，尽管它们与负责各种功能的各种皮质区域合作。例如，BG的四个主要核团，尾状核（NC），壳核（PU），以及苍白球（GP）的内部（GPi）和外部（GPe）参与强化学习，选择，处理和控制运动命令，边缘系统反应以及抑制不期望的动作。因此，BG、皮质和丘脑之间的适当相互作用是人类行为的基础。因此，迫切需要更好地了解BG和Th的不同核团如何与皮质协同工作。此外，这些知识对于解释神经系统、神经退行性疾病和精神疾病如何改变大脑功能至关重要。因此，我们的主要目标是提供BG的功能图谱，以增强对这些结构如何协同工作的理解。因此，我们希望通过应用9.4特斯拉的高分辨率MRI来研究人类BG和Th的分离和整合功能区域，并确定它们与皮质的连接概况。由于在9.4特斯拉的高场MRI中增加的信号/噪声提供了上级空间和时间分辨率，我们希望在这些核中识别功能亚基。使用专用的T1和T2加权序列和定量磁化率图，我们的目标是：a）评估BG的四个核的解剖学描绘，B）进行高分辨率（< 1 mm 3）静息状态（rs-fMRI）和任务相关的功能MRI c）鉴定这些核内的功能亚基，和d）分析它们与i）皮质区和ii）丘脑不同亚单位的连接模式。最后，我们计划分析iii）在静止和不同任务条件下，这些结构之间是否存在整体对应性和一致性。我们假设存在一个可靠的和可重复的功能性分组的BG，这可以通过高分辨率成像识别。此外，我们预计，在休息和任务之间的包裹和连接将有所不同，因为它是由正在进行的运动，体感和边缘处理的影响。

Subcortical structures of the human brain comprise a large number of different nuclei, which account for about 25% of the total brain volume. The largest nuclei are assembled in the basal ganglia (BG) and the thalamus (Th), which both possess a relatively homogeneous anatomical structure, although they are in cooperation with various cortical areas responsible for a variety of functions. For example the four major nuclei of the BG, the caudate nucleus (NC), putamen (PU), and the internal (GPi) and external part (GPe) of the globus pallidum (GP) are involved in reinforcement learning, selection, processing, and control of motor commands, in limbic reactions, as well as in the inhibition of undesired actions. Thus, the proper interplay between the BG, cortex, and thalamus are fundamental for human behavior. Therefore, a better understanding of how the different nuclei of the BG and the Th work in concert with the cortex is urgently required. Moreover, such knowledge is of utmost importance to explain how neurological, neurodegenerative and psychiatric disorders alter brain function. Thus, our primary goal is to deliver a functional atlas of the BG to enhance the understanding of how these structures work together.We, therefore, want to investigate the segregated and integrative functional areas of the human BG and the Th and to determine their connectivity profiles with the cortex by applying high-resolution MRI at 9.4 Tesla. As the increased signal/noise at high-field MRI at 9.4 Tesla offers a superior spatial and temporal resolution, we hope to identify functional subunit within these nuclei. Using dedicated T1- and T2-weighted sequences and quantitative susceptibility maps we aim to: a) assess the anatomical delineation of the four nuclei of the BG, b) perform high-resolution (< 1 mm3) resting state (rs-fMRI) and task-related functional MRI (task-fMRI) measurements in groups of healthy controls, c) identify functional subunits within these nuclei, and d) analyze their connectivity patterns to i) cortical areas and ii) to different subunits of the thalamus. Finally, we plan to analyze iii) whether an overall correspondence and consistency exist between these structures at rest and during different task conditions. We hypothesize the existence of a reliable and reproducible functional parcellation of the BG, which can be identified via high-resolution imaging. Furthermore, we expect that parcellation and connectivity will differ between rest and task as it is influenced by the ongoing motor, somatosensory, and limbic processing.