Reduced default mode network connectivity following combat trauma

• Type of Material: Article
• Authors: Julia A. DiGangi, Jesse Brown Veterans Administration Medical Center; Armin Tadayyon, University of Illinois at Chicago; Daniel A. Fitzgerald, Jesse Brown Veterans Administration Medical Center; Christine A. Rabinak, Wayne State University; Amy Kennedy, Jesse Brown Veterans Administration Medical Center; Heide Klumpp, University of Illinois at Chicago; Sheila Rauch, Emory University; K. Luan Phan, Jesse Brown Veterans Administration Medical Center
• Language: English
• Date: 2016-02-26
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2016 Published by Elsevier Ireland Ltd.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.neulet.2016.01.010
• Title of Journal or Parent Work: Neuroscience Letters
• ISSN: 0304-3940
• Volume: 615
• Start Page: 37
• End Page: 43
• Grant/Funding Information: This work was also supported by a grant from the National Institute of Mental Health (MH093679 to HK).; This research study was supported by a Veterans Affairs Merit Review Program Award (to KLP) issued by the Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development.
• Keywords: Adult; Rest; Male; fMRI; Stress Disorders, Post-Traumatic; Magnetic Resonance Imaging; Trauma; DMN; Adolescent; War-Related Injuries; Humans; Young Adult; PTSD; Combat; Parietal Lobe; Prefrontal Cortex
• Research Categories: Psychology, Psychobiology; Biology, Neuroscience; Health Sciences, Mental Health

Abstract

Recent studies show decreased functional connectivity in the default mode network (DMN) in PTSD; however, few have directly examined combat trauma specifically. There is limited understanding of how combat itself may affect the DMN. Some literature suggests that trauma exposure, rather than PTSD, can disrupt the DMN. To further elucidate the effect of trauma and PTSD on the DMN, we investigated DMN functional connectivity during the resting-state in veterans with PTSD, combat-exposed controls, and never-traumatized healthy controls. Results revealed that DMN connectivity was reduced in veterans exposed to combat trauma with and without PTSD compared to healthy civilian controls. Specifically, both groups of veterans demonstrated weaker connectivity within a network involving the precuneus, medial prefrontal cortex (mPFC) and right superior parietal lobule regardless of whether the mPFC or precuneus was chosen as a seed region. Findings suggest that the experience of trauma, rather than the pathology of PTSD, may be related to DMN changes.