Krüger Oliver, Klose Uwe, Hagberg Gisela E, Shiozawa-Bayer Thomas, Evrard Henry, Meszaros Cintia, Ethofer Thomas, Scheffler Klaus, Ernemann Ulrike, Bender Benjamin
Department of Diagnostic and Interventional Neuroradiology, University of Tübingen, Tübingen, Germany.
High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany.
PLoS One. 2025 May 7;20(5):e0323113. doi: 10.1371/journal.pone.0323113. eCollection 2025.
The bed nucleus of the stria terminalis (BST) and the ventromedial striatum (consisting of the head of the caudate nucleus (hCN) and the nucleus accumbens (NAcc)) are both part of complex, foremost limbic networks involved in a variety of neuropsychiatric conditions. However, data on functional or structural connections between the BST and hCN in humans are scarce. In an earlier study using both diffusion tensor magnetic resonance imaging (DTI) and conventional histology we found a pathway from the BST to the orbitofrontal cortex apparently passing directly through the hCN. To confirm this finding, we now examined the hCN in human ex-vivo brain tissue using polarized light microscopy (PLM), a method particularly suitable for depicting myelinated nerve fibers. We further examined whether differences in fiber distribution inside the hCN could be depicted using high-resolution DTI data. PLM revealed different fiber populations inside the hCN and the NAcc. Fibers in the hCN were mostly related to the anterior limb of the internal capsule (ALIC) with some apparently terminating in the hCN while the majority exited the hCN to enter the prefrontal white matter. Fibers originating from the BST were only scarcely seen on this level and appeared to either terminate inside the hCN or join the ALIC. On levels below the anterior commissure, the BST strongly connected 1) to other basal forebrain structures including the NAcc, and 2) with the white matter of the medial prefrontal cortex. Differences in fiber density within the hCN could be reproduced on MRI data but with strong interindividual variation. In summary, PLM revealed a much more complex fiber architecture in the region of interest than suggested by our earlier DTI findings. The study at hand shows that PLM can be a valuable tool for the verification of unclear or ambiguous DTI fiber tracking results.
终纹床核（BST）和腹内侧纹状体（由尾状核头部（hCN）和伏隔核（NAcc）组成）都是复杂的、主要的边缘系统网络的一部分，这些网络涉及多种神经精神疾病。然而，关于人类BST和hCN之间功能或结构连接的数据却很少。在早期一项同时使用扩散张量磁共振成像（DTI）和传统组织学的研究中，我们发现了一条从BST到眶额皮质的通路，该通路显然直接穿过hCN。为了证实这一发现，我们现在使用偏振光显微镜（PLM）检查了人类离体脑组织中的hCN，PLM是一种特别适合描绘有髓神经纤维的方法。我们进一步研究了是否可以使用高分辨率DTI数据描绘hCN内部纤维分布的差异。PLM显示hCN和NAcc内部存在不同的纤维群。hCN中的纤维大多与内囊前肢（ALIC）相关，一些纤维显然终止于hCN，而大多数纤维则离开hCN进入前额叶白质。在此层面上，仅很少能看到源自BST的纤维，它们似乎要么终止于hCN内部，要么加入ALIC。在前连合下方的层面，BST与1）包括NAcc在内的其他基底前脑结构以及2）内侧前额叶皮质的白质有强烈连接。hCN内纤维密度的差异可以在MRI数据上重现，但个体间差异很大。总之，PLM显示感兴趣区域的纤维结构比我们早期DTI研究结果所显示的要复杂得多。本研究表明，PLM可以成为验证不明确或模糊的DTI纤维追踪结果的有价值工具。
