Department of Psychiatry, VA Boston Healthcare System, Brockton Division, Brockton, MA, 02301, USA.
Harvard Medical School, Boston, MA, 02115, USA.
Mol Psychiatry. 2023 Jun;28(6):2301-2311. doi: 10.1038/s41380-023-02031-0. Epub 2023 May 12.
Alterations in brain connectivity may underlie neuropsychiatric conditions such as schizophrenia. We here assessed the degree of convergence of frontostriatal fiber projections in 56 young adult healthy controls (HCs) and 108 matched Early Psychosis-Non-Affective patients (EP-NAs) using our novel fiber cluster analysis of whole brain diffusion magnetic resonance imaging tractography.
Using whole brain tractography and our fiber clustering methodology on harmonized diffusion magnetic resonance imaging data from the Human Connectome Project for Early Psychosis we identified 17 white matter fiber clusters that connect frontal cortex (FCtx) and caudate (Cd) per hemisphere in each group. To quantify the degree of convergence and, hence, topographical relationship of these fiber clusters, we measured the inter-cluster mean distances between the endpoints of the fiber clusters at the level of the FCtx and of the Cd, respectively.
We found (1) in both groups, bilaterally, a non-linear relationship, yielding convex curves, between FCtx and Cd distances for FCtx-Cd connecting fiber clusters, driven by a cluster projecting from inferior frontal gyrus; however, in the right hemisphere, the convex curve was more flattened in EP-NAs; (2) that cluster pairs in the right (p = 0.03), but not left (p = 0.13), hemisphere were significantly more convergent in HCs vs EP-NAs; (3) in both groups, bilaterally, similar clusters projected significantly convergently to the Cd; and, (4) a significant group by fiber cluster pair interaction for 2 right hemisphere fiber clusters (numbers 5, 11; p = .00023; p = .00023) originating in selective PFC subregions.
In both groups, we found the FCtx-Cd wiring pattern deviated from a strictly topographic relationship and that similar clusters projected significantly more convergently to the Cd. Interestingly, we also found a significantly more convergent pattern of connectivity in HCs in the right hemisphere and that 2 clusters from PFC subregions in the right hemisphere significantly differed in their pattern of connectivity between groups.
大脑连接的改变可能是精神神经疾病的基础，如精神分裂症。在这里，我们使用新颖的全脑弥散磁共振成像纤维追踪纤维聚类分析，评估了 56 名年轻成年健康对照者（HCs）和 108 名匹配的早期精神病非情感障碍患者（EP-NAs）的额纹状体纤维投射的收敛程度。
我们使用来自早期精神病人类连接组计划的全脑追踪和我们的纤维聚类方法，对协调的弥散磁共振成像数据进行了分析，在每个组中都识别了 17 个连接额皮质（FCtx）和尾状核（Cd）的白质纤维簇。为了量化这些纤维簇的收敛程度，从而量化它们的拓扑关系，我们测量了纤维簇终点之间的跨簇平均距离，分别在 FCtx 和 Cd 的水平上。
我们发现（1）在两组中，双侧额纹状体和尾状核之间的 FCtx-Cd 连接纤维簇的距离呈现出一种非线性关系，产生了凸曲线，这种关系由来自下额回的一个纤维簇驱动；然而，在右侧半球，凸曲线更为平坦；（2）在右侧（p=0.03），而不是左侧（p=0.13），HCs 中纤维簇对的收敛程度显著高于 EP-NAs；（3）在两组中，双侧相似的纤维簇显著地向 Cd 投射；（4）两组中 2 个右侧半球纤维簇（编号 5、11；p=0.00023；p=0.00023）的纤维簇对之间存在显著的组间相互作用，这些纤维簇起源于选择性 PFC 亚区。
在两组中，我们发现 FCtx-Cd 布线模式偏离了严格的拓扑关系，相似的纤维簇向 Cd 投射的显著更为收敛。有趣的是，我们还发现 HCs 右侧半球的连接模式具有明显更收敛的模式，并且右侧 PFC 亚区的 2 个纤维簇在组间的连接模式上存在显著差异。
