title: Response inhibition failure to visual stimuli paired with a "single-type" stressor in PTSD patients: an fMRI pilot study.
abstract: Patients with post-traumatic stress disorder (PTSD) tend to misinterpret innocuous stimuli as potential threats, possibly due to a conditioning provoked by traumatic episodes. Previous neuroimaging evidence has shown an abnormal activation of the amygdala and prefrontal cortex in PTSD patients during fear conditioning and extinction. Nevertheless, the effects of a single-type adverse stressor on that circuit remain poorly explored. We tested the hypothesis that a single-type adverse episode is able to affect the prefrontal cortex and amygdala response to conditioned stimuli. To test this hypothesis, fMRI recordings were performed in PTSD patients and trauma-exposed controls during the observation of neutral and negative paired or non-paired pictures with an adverse stimulus by means of a single association. Results showed that left amygdala activation during negative reinforced stimuli was correlated with the score of PTSD clinical scale across all subjects. Furthermore, in the traumatized non-PTSD group, the activation of the dorso-medial prefrontal cortex and bilateral amygdala was lower during the observation of the reinforced (CS(+)) versus non-reinforced pictures (CS(-)) in response to emotionally negative stimuli. This was not the case in the PTSD patients. These results suggest that in PTSD patients, a single-episode conditioning unveils the failure of an inhibitory mechanism moderating the activity of the prefrontal cortex and amygdala in response to adverse and neutral stimuli.
authors: Institute of Advanced Biomedical Technologies, University of Chieti, Italy; Department of Neuroscience, Imaging & Clinical Science, University of Chieti, Italy. Electronic address: mbrunetti@itab.unich.it.
authors: Marcella
authors: M
authors: Brunetti
authors: Institute of Advanced Biomedical Technologies, University of Chieti, Italy; Department of Neuroscience, Imaging & Clinical Science, University of Chieti, Italy; Department of Basic Medical Sciences, Neurosciences and Sense Organs, University "A. Moro", Bari, Italy.
authors: Gianna
authors: G
authors: Sepede
authors: Institute of Advanced Biomedical Technologies, University of Chieti, Italy; Department of Neuroscience, Imaging & Clinical Science, University of Chieti, Italy.
authors: Antonio
authors: A
authors: Ferretti
authors: IZKF - Medicine Faculty of RWTH University, Aachen, Germany.
authors: Gianluca
authors: G
authors: Mingoia
authors: Institute of Advanced Biomedical Technologies, University of Chieti, Italy; Department of Neuroscience, Imaging & Clinical Science, University of Chieti, Italy.
authors: Gian Luca
authors: GL
authors: Romani
authors: Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy; IRCCS San Raffaele Pisana, Rome, Italy.
authors: Claudio
authors: C
authors: Babiloni
mesh_terms: D000059:Accidents; D000328:Adult; D001336:Automobiles; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D003213:Conditioning, Psychological / Q000502:physiology*; D055866:Earthquakes; D004651:Employment; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D010865:Pilot Projects; D013216:Reflex, Startle / Q000502:physiology; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Amygdala; Conditioning; Emotion; Functional magnetic resonance imaging (fMRI); Post-traumatic stress disorder (PTSD)