The subcallosal cingulate (SCC) area is a putative hub in the brain network underlying depression. Deep brain stimulation (DBS) targeting a particular subregion of SCC, identified as the intersection of forceps minor (FM), uncinate fasciculus (UCF), cingulum and fronto‐striatal fiber bundles, may be critical to a therapeutic response in patients with severe, treatment‐resistant forms of major depressive disorder (MDD). The pattern and variability of the white matter anatomy and organization within SCC has not been extensively characterized across individuals. The goal of this study is to investigate the variability of white matter bundles within the SCC that structurally connect this region with critical nodes in the depression network. Structural and diffusion data from 100 healthy subjects from the Human Connectome Project database were analyzed. Anatomically defined SCC regions were used as seeds to perform probabilistic tractography and to estimate the connectivity from the SCC to subject‐specific target areas believed to be involved in the pathology of MDD including ventral striatum (VS), UCF, anterior cingulate cortex (ACC), and medial prefrontal cortex (mPFC). Four distinct areas of connectivity were identified within SCC across subjects: (a) postero‐lateral SCC connectivity to medial temporal regions via UCF, (b) postero‐medial connectivity to VS, (c) superior‐medial connectivity to ACC via cingulum bundle, and (d) antero‐lateral connectivity to mPFC regions via forceps minor. Assuming white matter connectivity is critical to therapeutic response, the improved anatomic understanding of SCC as well as an appreciation of the intersubject variability are critical to developing optimized therapeutic targeting for SCC DBS.

中文翻译：

---

胼胝体下扣带回白质解剖结构的变异性

胼胝体下扣带回 (SCC) 区域是潜在抑郁症的大脑网络中推定的枢纽。针对 SCC 特定亚区的深部脑刺激 (DBS)，被确定为小镊子 (FM)、钩束 (UCF)、扣带和额纹状体纤维束的交叉点，可能对严重、重度抑郁症（MDD）的难治性形式。SCC 内白质解剖和组织的模式和变异性尚未在个体中得到广泛表征。本研究的目的是调查 SCC 内白质束的变异性，这些白质束在结构上将该区域与抑郁症网络中的关键节点连接起来。分析了来自 Human Connectome Project 数据库的 100 名健康受试者的结构和扩散数据。以解剖学定义的 SCC 区域作为种子进行概率性纤维束成像，并估计从 SCC 到被认为与 MDD 病理学有关的受试者特定目标区域的连通性，包括腹侧纹状体 (VS)、UCF、前扣带皮层 (ACC)和内侧前额叶皮层 (mPFC)。在跨受试者的 SCC 内确定了四个不同的连接区域：（a）后外侧 SCC 通过 UCF 连接到内侧颞区，（b）后内侧连接到 VS，（c）上内侧通过扣带束连接到 ACC， (d) 通过小镊子与 mPFC 区域的前外侧连接。假设白质连接对治疗反应至关重要，