title: The innate alarm circuit in post-traumatic stress disorder: Conscious and subconscious processing of fear- and trauma-related cues.
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.
authors.affiliation: Department of Psychiatry, University of Western Ontario, University Hospital (Room C3-103), 339 Windermere Road, London, ON, Canada N6A 5A5.
authors.forename: Daniela
authors.initials: D
authors.lastname: Rabellino
authors.affiliation: Department of Psychiatry, University of Western Ontario, University Hospital (Room C3-103), 339 Windermere Road, London, ON, Canada N6A 5A5.
authors.forename: Maria
authors.initials: M
authors.lastname: Densmore
authors.affiliation: 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.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Frewen
authors.affiliation: 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.
authors.forename: Jean
authors.initials: J
authors.lastname: Théberge
authors.affiliation: 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.
authors.forename: Ruth A
authors.initials: RA
authors.lastname: Lanius
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D001143:Arousal / Q000502:physiology*; D001933:Brain Stem / Q000503:physiopathology*; D002531:Cerebellum / Q000503:physiopathology*; D003243:Consciousness; D003463:Cues; D005239:Fear / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D000067073:Psychological Trauma / Q000503:physiopathology*; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology*; D013360:Subliminal Stimulation; D014473:Unconscious, Psychology
keywords: Alarm system; Cerebellum; Hyperarousal; PTSD; Periaqueductal gray; Re-experiencing; fMRI