Cisler Josh M
Department of Psychiatry, University of Wisconsin-Madison, MadisonWI, USA.
Front Syst Neurosci. 2017 May 11;11:29. doi: 10.3389/fnsys.2017.00029. eCollection 2017.
Altered functional connectivity (FC) between the medial prefrontal cortex (mPFC) and amygdala is widely implicated as a neural mechanism explaining risk for psychopathology among those exposed to early life trauma. Nonetheless, contemporary neuroimaging research has shifted toward large-scale network models of brain function, and it is not clear how this common bi-nodal finding fits into larger-scale network models. Here, using dynamic functional connectivity (DFC) approaches combined with large-scale network analyses, the larger role of bi-nodal FC between mPFC and amygdala among a sample of adolescent girls is investigated. The sample was comprised of 30 healthy control girls and 26 girls exposed to either physical or sexual assault who underwent a resting-state scan during 3T MRI. DFC using a sliding window approach was used to create weighted, undirected, graphs from the resting-state data following parcellation with a 215 regions-of-interest (ROI) atlas. Using ROI, the predicted finding of lessor FC between mPFC and amygdala as a function of early life trauma was replicated in this sample. By contrast, early life trauma was associated with greater large-scale network modularity. Using a dynamic FC approach, it is also demonstrated that within-subject variability in this bi-nodal FC closely tracks within-subject fluctuations in large-scale network patterns, including connectivity between a limbic and default mode network (in which the amygdala and mPFC nodes belong, respectively) as well as overall modular organization. These results suggest that bi-nodal FC, such as amygdala-mPFC FC, may generally reflect larger-scale network patterns. Future research is necessary to understand whether these associations between nodal FC and large-scale network organization better reflect top-down processes (larger-scale network organization drives bi-nodal FC) or bottom-up processes (bi-nodal FC drives larger-scale network organization) and the related impact of early life trauma.
内侧前额叶皮质（mPFC）与杏仁核之间功能连接性（FC）的改变被广泛认为是一种神经机制，可解释早年生活创伤人群的精神病理学风险。尽管如此，当代神经影像学研究已转向大脑功能的大规模网络模型，目前尚不清楚这一常见的双节点发现如何融入更大规模的网络模型。在此，通过结合大规模网络分析的动态功能连接性（DFC）方法，研究了mPFC与杏仁核之间双节点FC在一组青春期女孩样本中的更大作用。该样本包括30名健康对照女孩和26名遭受身体或性侵犯的女孩，她们在3T磁共振成像（MRI）期间接受了静息态扫描。使用滑动窗口方法的DFC用于根据一个包含215个感兴趣区域（ROI）图谱的分割，从静息态数据创建加权、无向图。使用ROI，在该样本中复制了作为早年生活创伤函数的mPFC与杏仁核之间FC降低的预测结果。相比之下，早年生活创伤与更大的大规模网络模块化相关。使用动态FC方法还表明，这种双节点FC的个体内变异性紧密跟踪大规模网络模式的个体内波动，包括边缘系统与默认模式网络（杏仁核和mPFC节点分别属于该网络）之间的连接以及整体模块化组织。这些结果表明，双节点FC，如杏仁核 - mPFC FC，可能通常反映更大规模的网络模式。未来有必要进行研究，以了解节点FC与大规模网络组织之间的这些关联是否更好地反映自上而下的过程（更大规模的网络组织驱动双节点FC）或自下而上的过程（双节点FC驱动更大规模的网络组织）以及早年生活创伤的相关影响。
