Post-traumatic stress disorder (PTSD) is a chronic disease caused by traumatic incidents. Numerous studies have revealed grey matter volume differences in affected individuals. The nature of the disease renders it difficult to distinguish between a priori versus a posteriori changes. To overcome this difficulty, we studied the consequences of a traumatic event on brain morphology in mice before and 4 weeks after exposure to brief foot shocks (or sham treatment), and correlated morphology with symptoms of hyperarousal. In the latter context, we assessed hyperarousal upon confrontation with acoustic, visual, or composite (acoustic/visual/tactile) threats and integrated the individual readouts into a single Hyperarousal Score using logistic regression analysis. MRI scans with subsequent whole-brain deformation-based morphometry (DBM) analysis revealed a volume decrease of the dorsal hippocampus and an increase of the reticular nucleus in shocked mice when compared to non-shocked controls. Using the Hyperarousal Score as regressor for the post-exposure MRI measurement, we observed negative correlations with several brain structures including the dorsal hippocampus. If the development of changes with respect to the basal MRI was considered, reduction in globus pallidus volume reflected hyperarousal severity. Our findings demonstrate that a brief traumatic incident can cause volume changes in defined brain structures and suggest the globus pallidus as an important hub for the control of fear responses to threatening stimuli of different sensory modalities.

创伤后应激障碍（PTSD）是一种由创伤事件引起的慢性疾病。许多研究揭示了受影响个体的灰质体积差异。该疾病的性质使得难以区分先验与后天的变化。为了克服这一困难，我们研究了在暴露于短暂的足部电击（或假治疗）之前和之后 4 周，创伤事件对小鼠大脑形态的影响，并将形态与过度兴奋的症状相关联。在后一种情况下，我们评估了面对听觉、视觉或复合（听觉/视觉/触觉）威胁时的过度唤醒，并使用逻辑回归分析将单个读数整合到单个过度唤醒分数中。MRI 扫描和随后的基于全脑变形的形态测量 (DBM) 分析显示，与未电击的对照组相比，电击小鼠的背侧海马体体积减少，网状核增加。使用过度唤醒评分作为暴露后 MRI 测量的回归量，我们观察到与包括背侧海马体在内的几种大脑结构呈负相关。如果考虑到基础 MRI 变化的发展，苍白球体积的减少反映了过度觉醒的严重程度。我们的研究结果表明，短暂的创伤事件会导致特定大脑结构的体积变化，并表明苍白球是控制对不同感觉方式的威胁刺激的恐惧反应的重要枢纽。