Neural dysregulation in posttraumatic stress disorder

Sripada, Rebecca K, King, Anthony P, Welsh, Robert C, Garfinkel, Sarah N, Wang, Xin, Sripada, Chandra S and Liberzon, Israel (2012) Neural dysregulation in posttraumatic stress disorder. Psychosomatic Medicine, 74 (9). pp. 904-911. ISSN 0033-3174

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Abstract

Objective—Convergent neuroimaging and neuropsychological research demonstrates disrupted
attention and heightened threat sensitivity in PTSD. This might be linked to aberrations in largescale
networks subserving detection of salient stimuli, i.e. the salience network (SN), and
stimulus-independent, internally-focused thought, i.e. the default mode network (DMN).
Methods—Resting state brain activity was measured in returning veterans who served in Iraq or
Afghanistan with (n=15) and without PTSD (n=15) and in healthy community controls (n=15).
Correlation coefficients were calculated between the time course of seed regions in key SN and
DMN regions (posterior cingulate, ventromedial prefrontal cortex, and bilateral anterior insula)
and all other voxels of the brain.
Results—Compared to control groups, PTSD participants showed reduced functional
connectivity within DMN (between DMN seeds and other DMN regions), including rostral ACC/
vmPFC (Z=3.31; p=.005, corrected) and hippocampus (Z=2.58; p=.005), and increased
connectivity within SN (between insula seeds and other SN regions), including amygdala (Z=3.03;
p=.01, corrected). PTSD participants also demonstrated increased cross-network connectivity.
DMN seeds exhibited elevated connectivity with SN regions, including insula (Z=3.06; p=.03,
corrected), putamen, and supplementary motor area (Z=4.14; Z=4.08; p<.001), and SN seeds
exhibited elevated connectivity with DMN regions, including hippocampus (Z=3.10; p=.048,
corrected).
Conclusions—During resting state scanning, PTSD participants showed reduced coupling
within DMN, greater coupling within SN, and increased coupling between DMN and SN. Our
findings suggest a relative dominance of threat-sensitive circuitry in PTSD, even in task-freeconditions. Disequilibrium between large-scale networks subserving salience detection versus
internally focused thought may be associated with PTSD pathophysiology

Item Type: Article
Schools and Departments: Brighton and Sussex Medical School > Brighton and Sussex Medical School
Brighton and Sussex Medical School > Neuroscience
Subjects: R Medicine > RC Internal medicine > RC0321 Neurosciences. Biological psychiatry. Neuropsychiatry
Depositing User: Jonathan Williams
Date Deposited: 11 Sep 2015 14:39
Last Modified: 26 Sep 2017 11:33
URI: http://sro.sussex.ac.uk/id/eprint/56669

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