Aberrant Functional Connectivity of the Amygdala Complexes in PTSD during Conscious and Subconscious Processing of Trauma-Related Stimuli

PLoS One. 2016 Sep 15;11(9):e0163097. doi: 10.1371/journal.pone.0163097. eCollection 2016.

Abstract

Post-traumatic stress disorder (PTSD) is characterized by altered functional connectivity of the amygdala complexes at rest. However, amygdala complex connectivity during conscious and subconscious threat processing remains to be elucidated. Here, we investigate specific connectivity of the centromedial amygdala (CMA) and basolateral amygdala (BLA) during conscious and subconscious processing of trauma-related words among individuals with PTSD (n = 26) as compared to non-trauma-exposed controls (n = 20). Psycho-physiological interaction analyses were performed using the right and left amygdala complexes as regions of interest during conscious and subconscious trauma word processing. These analyses revealed a differential, context-dependent responses by each amygdala seed during trauma processing in PTSD. Specifically, relative to controls, during subconscious processing, individuals with PTSD demonstrated increased connectivity of the CMA with the superior frontal gyrus, accompanied by a pattern of decreased connectivity between the BLA and the superior colliculus. During conscious processing, relative to controls, individuals with PTSD showed increased connectivity between the CMA and the pulvinar. These findings demonstrate alterations in amygdala subregion functional connectivity in PTSD and highlight the disruption of the innate alarm network during both conscious and subconscious trauma processing in this disorder.

MeSH terms

  • Adult
  • Amygdala / physiopathology*
  • Case-Control Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Stress Disorders, Post-Traumatic / physiopathology*

Grant support

This study was supported by the Canadian Institutes of Health Research (#MOP97914). Daniela Rabellino was supported by fellowship from MITACS and Homewood Research Institute. Canadian Institutes of Health Research: http://www.cihr-irsc.gc.ca/e/193.html. RL MITACS http://www.mitacs.ca/en. DR. Homewood Research Institute http://www.homewoodresearch.org/ DR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.