The innate alarm circuit in post-traumatic stress disorder: Conscious and subconscious processing of fear- and trauma-related cues

Daniela Rabellino; Maria Densmore; Paul A Frewen; Jean Théberge; Ruth A Lanius

doi:10.1016/j.pscychresns.2015.12.005

The innate alarm circuit in post-traumatic stress disorder: Conscious and subconscious processing of fear- and trauma-related cues

Psychiatry Res Neuroimaging. 2016 Feb 28:248:142-50. doi: 10.1016/j.pscychresns.2015.12.005. Epub 2015 Dec 23.

Authors

Daniela Rabellino¹, Maria Densmore¹, Paul A Frewen², Jean Théberge³, Ruth A Lanius⁴

Affiliations

¹ Department of Psychiatry, University of Western Ontario, University Hospital (Room C3-103), 339 Windermere Road, London, ON, Canada N6A 5A5.
² Department of Psychiatry, University of Western Ontario, University Hospital (Room C3-103), 339 Windermere Road, London, ON, Canada N6A 5A5; Department of Psychology, University of Western Ontario, London, ON, Canada; Department of Neuroscience, University of Western Ontario, London, ON, Canada.
³ Department of Psychiatry, University of Western Ontario, University Hospital (Room C3-103), 339 Windermere Road, London, ON, Canada N6A 5A5; Department of Medical Imaging, Lawson Health Research Institute, London, ON, Canada.
⁴ Department of Psychiatry, University of Western Ontario, University Hospital (Room C3-103), 339 Windermere Road, London, ON, Canada N6A 5A5; Department of Neuroscience, University of Western Ontario, London, ON, Canada. Electronic address: ruth.lanius@lhsc.on.ca.

PMID: 26749205
DOI: 10.1016/j.pscychresns.2015.12.005

Abstract

Fast defensive responses to salient threatening stimuli are an important clinical feature of post-traumatic stress disorder (PTSD). We investigated the neural correlates of subliminal and supraliminal processing of fearful faces and individualized trauma-related words in individuals with PTSD (n=26) compared with healthy controls (n=20) using functional magnetic resonance imaging. Increased activity in the right cerebellum and the posterior cingulum was observed in individuals with PTSD during subliminal processing of trauma-related words, whereas increased activity of the basal forebrain was found within the PTSD group when processing supraliminal trauma-related words. Moreover, significant positive correlations were found between re-experiencing symptoms and response within the amygdala, and between hyper-arousal symptoms and response within the periaqueductal gray matter, during subliminal processing of trauma-related words and during supraliminal processing of fearful faces, respectively. These findings further our understanding of rapid threat processing and defensive responses, highlighting the role of the cerebellum and periaqueductal gray matter as part of an 'innate alarm system' in PTSD.

Keywords: Alarm system; Cerebellum; Hyperarousal; PTSD; Periaqueductal gray; Re-experiencing; fMRI.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Amygdala / physiopathology*
Arousal / physiology*
Brain Stem / physiopathology*
Cerebellum / physiopathology*
Consciousness
Cues*
Fear / physiology*
Female
Humans
Magnetic Resonance Imaging
Male
Middle Aged
Psychological Trauma / physiopathology*
Stress Disorders, Post-Traumatic / physiopathology*
Subliminal Stimulation
Unconscious, Psychology

Grants and funding

97914/Canadian Institutes of Health Research/Canada