消退过程中恐惧增强的惊吓反应与白质微观结构和功能连接性相关。
Fear-potentiated startle during extinction is associated with white matter microstructure and functional connectivity.
作者信息
Fani Negar, King Tricia Z, Brewster Ryan, Srivastava Amita, Stevens Jennifer S, Glover Ebony M, Norrholm Seth D, Bradley Bekh, Ressler Kerry J, Jovanovic Tanja
机构信息
Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA.
Department of Psychology, Georgia State University, Atlanta, GA, USA.
出版信息
Cortex. 2015 Mar;64:249-59. doi: 10.1016/j.cortex.2014.11.006. Epub 2014 Nov 26.
BACKGROUND
Extinction of conditioned fear is an associative learning process that involves communication among the hippocampus, medial prefrontal cortex, and amygdala. Strength of connectivity between the hippocampus and the anterior cingulate cortex (ACC), and between the amygdala and ventromedial prefrontal cortex (vmPFC), may influence fear-potentiated startle (FPS) responses during extinction. Specific white matter tracts, the cingulum and uncinate fasciculus (UF), serve as primary routes of communication for these areas. Our objective was to investigate associations between FPS during extinction and cingulum and UF connectivity.
METHOD
Diffusion tensor imaging (DTI) and probabilistic tractography analyses were used to examine cingulum and UF structural connectivity in 40 female African-Americans with psychological trauma exposure. FPS responses during fear conditioning and extinction were assessed via electromyography (EMG) of the right orbicularis oculi muscle. Secondarily, functional connectivity analyses were performed with the seed regions of interest (ROIs) used for tractography.
RESULTS
A significant negative association between cingulum microstructure and FPS during early extinction (r = -.42, p = .01) and late extinction (r = -.36, p = .03) was observed after accounting for the effects of age, trauma exposure, and psychopathology (post-traumatic stress disorder symptoms); this pattern was similar for early extinction and functional connectivity between these regions (p < .05(corrected)). No significant correlations were observed between FPS and UF microstructure.
CONCLUSIONS
These data indicate that structural integrity of the cingulum is directly associated with extinction learning and appears to influence functional connectivity between these regions. Decrements in cingulum microstructure may interfere with extinction learning, thereby increasing risk for the development of pathological anxiety.
背景
条件性恐惧的消退是一个联想学习过程，涉及海马体、内侧前额叶皮质和杏仁核之间的交流。海马体与前扣带回皮质（ACC）之间以及杏仁核与腹内侧前额叶皮质（vmPFC）之间的连接强度，可能会影响消退过程中恐惧增强的惊吓（FPS）反应。特定的白质束，即扣带束和钩束（UF），是这些区域之间交流的主要途径。我们的目的是研究消退过程中的FPS与扣带束和UF连接性之间的关联。
方法
采用扩散张量成像（DTI）和概率性纤维束成像分析，检查40名有心理创伤暴露史的非洲裔美国女性的扣带束和UF结构连接性。通过右侧眼轮匝肌的肌电图（EMG）评估恐惧条件反射和消退过程中的FPS反应。其次，使用用于纤维束成像的感兴趣种子区域（ROI）进行功能连接性分析。
结果
在考虑年龄、创伤暴露和精神病理学（创伤后应激障碍症状）的影响后，观察到扣带束微观结构与早期消退（r = -0.42，p = 0.01）和晚期消退（r = -0.36，p = 0.03）期间的FPS之间存在显著负相关；这种模式在早期消退以及这些区域之间的功能连接性方面相似（p < 0.05（校正））。未观察到FPS与UF微观结构之间存在显著相关性。
结论
这些数据表明，扣带束的结构完整性与消退学习直接相关，并且似乎会影响这些区域之间的功能连接性。扣带束微观结构的减少可能会干扰消退学习，从而增加病理性焦虑发展的风险。
Zotero 插件