Altered Resting-State Functional Connectivity of Basolateral and Centromedial Amygdala Complexes in Posttraumatic Stress Disorder |
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Authors: | Vanessa M Brown Kevin S LaBar Courtney C Haswell Andrea L Gold Mid-Atlantic MIRECC Workgroup Gregory McCarthy Rajendra A Morey |
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Affiliation: | 1.Mid-Atlantic MIRECC, Durham VA Medical Center, Durham VA, Durham, NC, USA;2.Duke-UNC Brain Imaging and Analysis Center, Duke University, Durham, NC, USA;3.Department of Psychology and Neuroscience, Duke University, Durham, NC, USA;4.Center for Cognitive Neuroscience, Duke University, Durham, NC, USA;5.Department of Psychology, Yale University, New Haven, CT, USA;6.Department of Psychiatry and Behavioral Sciences, Duke University, Durham, NC, USA |
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Abstract: | The amygdala is a major structure that orchestrates defensive reactions to environmental threats and is implicated in hypervigilance and symptoms of heightened arousal in posttraumatic stress disorder (PTSD). The basolateral and centromedial amygdala (CMA) complexes are functionally heterogeneous, with distinct roles in learning and expressing fear behaviors. PTSD differences in amygdala-complex function and functional connectivity with cortical and subcortical structures remain unclear. Recent military veterans with PTSD (n=20) and matched trauma-exposed controls (n=22) underwent a resting-state fMRI scan to measure task-free synchronous blood-oxygen level dependent activity. Whole-brain voxel-wise functional connectivity of basolateral and CMA seeds was compared between groups. The PTSD group had stronger functional connectivity of the basolateral amygdala (BLA) complex with the pregenual anterior cingulate cortex (ACC), dorsomedial prefrontal cortex, and dorsal ACC than the trauma-exposed control group (p<0.05; corrected). The trauma-exposed control group had stronger functional connectivity of the BLA complex with the left inferior frontal gyrus than the PTSD group (p<0.05; corrected). The CMA complex lacked connectivity differences between groups. We found PTSD modulates BLA complex connectivity with prefrontal cortical targets implicated in cognitive control of emotional information, which are central to explanations of core PTSD symptoms. PTSD differences in resting-state connectivity of BLA complex could be biasing processes in target regions that support behaviors central to prevailing laboratory models of PTSD such as associative fear learning. Further research is needed to investigate how differences in functional connectivity of amygdala complexes affect target regions that govern behavior, cognition, and affect in PTSD. |
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Keywords: | PTSD resting state amygdala basolateral amygdala centromedial amygdala functional connectivity |
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