PDF(Pubmed)
Abstract：
Cortico-striato-thalamo-cortical (CSTC) loops are fundamental organizing units in mammalian brains. CSTCs process limbic, associative, and sensorimotor information in largely separated but interacting networks. CTSC loops pass through paired striatal compartments, striosome (aka patch) and matrix, segregated pools of medium spiny projection neurons with distinct embryologic origins, cortical/subcortical structural connectivity, susceptibility to injury, and roles in behaviors and diseases. Similarly, striatal dopamine modulates activity in striosome and matrix in opposite directions. Routing CSTCs through one compartment may be an anatomical basis for regulating discrete functions. We used differential structural connectivity, identified through probabilistic diffusion tractography, to distinguish the striatal compartments (striosome-like and matrix-like voxels) in living humans. We then mapped compartment-specific projections and quantified structural connectivity between each striatal compartment, the globus pallidus interna (GPi), and 20 thalamic nuclei in 221 healthy adults. We found that striosome-originating and matrix-originating streamlines were segregated within the GPi: striosome-like connectivity was significantly more rostral, ventral, and medial. Striato-pallido-thalamic streamline bundles that were seeded from striosome-like and matrix-like voxels transited spatially distinct portions of the white matter. Matrix-like streamlines were 5.7-fold more likely to reach the GPi, replicating animal tract-tracing studies. Striosome-like connectivity dominated in six thalamic nuclei (anteroventral, central lateral, laterodorsal, lateral posterior, mediodorsal-medial, and medial geniculate). Matrix-like connectivity dominated in seven thalamic nuclei (centromedian, parafascicular, pulvinar-anterior, pulvinar-lateral, ventral lateral-anterior, ventral lateral-posterior, ventral posterolateral). Though we mapped all thalamic nuclei independently, functionally-related nuclei were matched for compartment-level bias. We validated these results with prior thalamostriate tract tracing studies in non-human primates and other species; where reliable data was available, all agreed with our measures of structural connectivity. Matrix-like connectivity was lateralized (left > right hemisphere) in 18 thalamic nuclei, independent of handedness, diffusion protocol, sex, or whether the nucleus was striosome-dominated or matrix-dominated. Compartment-specific biases in striato-pallido-thalamic structural connectivity suggest that routing CSTC loops through striosome-like or matrix-like voxels is a fundamental mechanism for organizing and regulating brain networks. Our MRI-based assessments of striato-thalamic connectivity in humans match and extend the results of prior tract tracing studies in animals. Compartment-level characterization may improve localization of human neuropathologies and improve neurosurgical targeting in the GPi and thalamus.
摘要：
皮质-纹状体-丘脑-皮质（CSTC）环是哺乳动物大脑中的基本组织单位。CSTCs工艺边缘，联想,和感觉运动信息在很大程度上分离但相互作用的网络中。CTSC环穿过成对的纹状体区室，纹状体(akapatch)和基质，具有不同胚胎起源的中等多刺投射神经元的隔离池，皮质/皮质下结构连接，易受伤害,以及在行为和疾病中的角色。同样，纹状体多巴胺以相反的方向调节纹状体和基质中的活性。将CSTC路由通过一个隔室可以是用于调节离散功能的解剖学基础。我们使用了差分结构连通性，通过概率扩散束成像识别，区分活体人类的纹状体区室（纹状体样和基质样体素）。然后，我们绘制了每个纹状体区室之间的区室特异性投影和量化的结构连通性，苍白球（GPi），221名健康成年人的20个丘脑核。我们发现，条纹体起源和矩阵起源的流线在GPi中被隔离：条纹体样连通性明显更多，腹侧,和中间。从条纹体样和矩阵样体素播种的条纹-苍白-丘脑流线束在空间上穿过白质的不同部分。矩阵状流线达到GPi的可能性高出5.7倍，复制动物道追踪研究。纹状体样连通性在六个丘脑核中占主导地位（前腹，中央侧方,侧臭，外侧后部，中臭-中间，和内侧膝状）。在七个丘脑核中占主导地位的基质样连通性(中心，旁肌，前肺动脉,pulvinar-lateral,腹侧前外侧，腹侧外侧-后侧，腹侧后外侧)。尽管我们独立地绘制了所有丘脑核，功能相关的细胞核与区室水平偏倚相匹配.我们通过先前在非人灵长类动物和其他物种中进行的丘脑纹束追踪研究验证了这些结果；在有可靠数据的情况下，所有人都同意我们的结构连通性措施。在18个丘脑核中，基质样连通性被侧向化(左>右半球)，独立于惯用手，扩散协议，性别,或者细胞核是以纹状体为主还是以基质为主。纹状体-pallido-丘脑结构连通性中的隔室特异性偏差表明，通过纹状体样或矩阵样体素路由CSTC循环是组织和调节大脑网络的基本机制。我们基于MRI对人类纹状体-丘脑连通性的评估与先前在动物中追踪研究的结果相匹配并扩展了结果。隔室水平表征可以改善人类神经病理学的定位并改善GPi和丘脑中的神经外科靶向。
