Olivé Isadora, Densmore Maria, Harricharan Sherain, Théberge Jean, McKinnon Margaret C, Lanius Ruth
Departments of Psychiatry, University of Western Ontario, London, Ontario, Canada.
Imaging Division, Lawson Health Research Institute, London, Ontario, Canada.
Hum Brain Mapp. 2018 Jan;39(1):563-574. doi: 10.1002/hbm.23865. Epub 2017 Nov 13.
The innate alarm system (IAS) models the neurocircuitry involved in threat processing in posttraumatic stress disorder (PTSD). Here, we investigate a primary subcortical structure of the IAS model, the superior colliculus (SC), where the SC is thought to contribute to the mechanisms underlying threat-detection in PTSD. Critically, the functional connectivity between the SC and other nodes of the IAS remains unexplored.
We conducted a resting-state fMRI study to investigate the functional architecture of the IAS, focusing on connectivity of the SC in PTSD (n = 67), its dissociative subtype (n = 41), and healthy controls (n = 50) using region-of-interest seed-based analysis.
We observed group-specific resting state functional connectivity between the SC for both PTSD and its dissociative subtype, indicative of dedicated IAS collicular pathways in each group of patients. When comparing PTSD to its dissociative subtype, we observed increased resting state functional connectivity between the left SC and the right dorsolateral prefrontal cortex (DLPFC) in PTSD. The DLPFC is involved in modulation of emotional processes associated with active defensive responses characterising PTSD. Moreover, when comparing PTSD to its dissociative subtype, increased resting state functional connectivity was observed between the right SC and the right temporoparietal junction in the dissociative subtype. The temporoparietal junction is involved in depersonalization responses associated with passive defensive responses typical of the dissociative subtype.
Our findings suggest that unique resting state functional connectivity of the SC parallels the unique symptom profile and defensive responses observed in PTSD and its dissociative subtype. Hum Brain Mapp 39:563-574, 2018. © 2017 Wiley Periodicals, Inc.
先天性警报系统（IAS）模拟了创伤后应激障碍（PTSD）中涉及威胁处理的神经回路。在此，我们研究IAS模型的一个主要皮质下结构——上丘（SC），据认为SC有助于PTSD中威胁检测的潜在机制。至关重要的是，SC与IAS其他节点之间的功能连接仍未得到探索。
我们进行了一项静息态功能磁共振成像研究，以调查IAS的功能结构，使用基于感兴趣区域种子点的分析方法，重点关注PTSD患者（n = 67）、其解离亚型患者（n = 41）和健康对照者（n = 50）的SC连接情况。
我们观察到PTSD及其解离亚型的SC之间存在特定组的静息态功能连接，这表明每组患者中存在专门的IAS丘系通路。当将PTSD与其解离亚型进行比较时，我们观察到PTSD患者左侧SC与右侧背外侧前额叶皮层（DLPFC）之间的静息态功能连接增加。DLPFC参与调节与PTSD特征性主动防御反应相关的情绪过程。此外，当将PTSD与其解离亚型进行比较时，在解离亚型中观察到右侧SC与右侧颞顶联合之间的静息态功能连接增加。颞顶联合参与与解离亚型典型的被动防御反应相关的人格解体反应。
我们的研究结果表明，SC独特的静息态功能连接与PTSD及其解离亚型中观察到的独特症状特征和防御反应平行。《人类大脑图谱》39:563 - 574，2018年。© 2017威利期刊公司。
