Tieu An N, Waugh Jeff L
Division of Pediatric Neurology, Department of Pediatrics, University of Texas Southwestern, Dallas, TX, United States.
Department of Neurology, University of Texas Southwestern, Dallas, TX, United States.
Front Psychiatry. 2025 Sep 1;16:1647240. doi: 10.3389/fpsyt.2025.1647240. eCollection 2025.
The striatum is among the most studied brain regions in Major Depressive Disorder (MDD) due to its involvement in reward, motivation, and executive functions. The striatum is comprised of interdigitated tissue compartments (matrix and striosome) that have distinct connectivity, pharmacology, and susceptibility to neuropsychiatric diseases. Each compartment is embedded in distinct functional networks, and functional networks that are abnormal in MDD (eg, the default mode and salience networks) selectively couple with the striosome. We hypothesized that imbalances in function between the striatal compartments could correlate with MDD. Historically, assessing compartment-specific involvement in MDD required histological staining of postmortem tissue, precluding or large-group analyses. In a cohort of 266 subjects (MDD and matched healthy controls), we used probabilistic diffusion tractography (connectivity-based parcellation) to identify striatal voxels with matrix-like and striosome-like patterns of connectivity. These compartment-like voxels recapitulated the anatomic features of matrix and striosome described in prior histologic assessments: their relative abundance, location biases within the striatum, somatotopic organization, and distinct patterns of structural connectivity. Prior studies found that decreased putaminal volume was associated with increased risk of developing MDD. We found decreased putaminal volume in MDD, accompanied by a shift from matrix-like to striosome-like volume. We observed an opposing shift in the caudate, from striosome-like to matrix-like volume, that correlated with the severity of MDD symptoms. Our findings suggest that MDD-associated decreased putaminal volume correlates with a shift from matrix-based functional networks toward striosome-dominated patterns in the putamen. Abnormalities of compartment function in the putamen may be a neuroanatomical correlate of the clinical features of MDD.
由于纹状体参与奖赏、动机和执行功能，它是重度抑郁症（MDD）中研究最多的脑区之一。纹状体由相互交错的组织区室（基质和纹状体小体）组成，这些区室具有不同的连接性、药理学特性以及对神经精神疾病的易感性。每个区室都嵌入在不同的功能网络中，而在MDD中异常的功能网络（例如默认模式网络和突显网络）与纹状体小体选择性耦合。我们假设纹状体区室之间的功能失衡可能与MDD相关。从历史上看，评估MDD中区室特异性的参与情况需要对死后组织进行组织学染色，这排除了对大量人群的分析。在一个由266名受试者（MDD患者和匹配的健康对照）组成的队列中，我们使用概率性扩散张量成像（基于连接性的脑区划分）来识别具有类似基质和类似纹状体小体连接模式的纹状体体素。这些类似区室的体素概括了先前组织学评估中描述的基质和纹状体小体的解剖特征：它们的相对丰度、在纹状体内的位置偏差、躯体定位组织以及不同的结构连接模式。先前的研究发现壳核体积减小与患MDD的风险增加有关。我们发现MDD患者的壳核体积减小，同时伴有从类似基质体积向类似纹状体小体体积的转变。我们在尾状核中观察到相反的转变，从类似纹状体小体体积向类似基质体积转变，这与MDD症状的严重程度相关。我们的研究结果表明，与MDD相关的壳核体积减小与从基于基质的功能网络向壳核中以纹状体小体为主的模式转变有关。壳核区室功能异常可能是MDD临床特征的神经解剖学相关因素。
