Tools for translational neuroscience: PTSD is associated with heightened fear responses using acoustic startle but not skin conductance measures

• Type of Material: Article
• Authors: Ebony M. Glover, Emory University; Justine E. Phifer, Emory University; Daniel F. Crain, Emory University; Seth Norrholm, Emory University; Michael Davis, Emory University; Bekh Bradley-Davino, Emory University; Kerry Ressler, Emory University; Tanja Jovanovic, Emory University
• Language: English
• Date: 2011-12-01
• Publisher: Wiley
• Publication Version: Final Published Version
• Copyright Statement: © 2011 Wiley Periodicals, Inc.
• License: Creative Commons Attribution-NonCommercial 2.5 Generic
• Final Published Version (URL): http://dx.doi.org/10.1002/da.20880
• Title of Journal or Parent Work: Depression and Anxiety
• ISSN: 1091-4269
• Volume: 28
• Issue: 12
• Start Page: 1058
• End Page: 1066
• Grant/Funding Information: This work was primarily supported by National Institutes of Mental Health (MH071537).; Support was also from Emory and Grady Memorial Hospital General Clinical Research Center, NIH National Centers for Research Resources (M01 RR00039), and the Burroughs Wellcome Fund.
• Keywords: Life Sciences & Biomedicine; psychophysiology; EXTINCTION; Psychology, Clinical; INHIBITION; skin conductance response; Psychiatry; fear-potentiated startle; MENSTRUAL-CYCLE; ANXIETY; CONDITIONED FEAR; AMYGDALA; TRAUMA; posttraumatic stress disorders; Psychology; trauma; Social Sciences; ANIMAL-MODELS; Science & Technology
• Research Categories: Biology, Neuroscience; Psychology, Physiological; Psychology, Clinical

Abstract

Background: Posttraumatic stress disorder (PTSD) patients show heightened fear responses to trauma reminders and an inability to inhibit fear in the presence of safety reminders. Brain imaging studies suggest that this is in part due to amygdala over-reactivity as well as deficient top-down cortical inhibition of the amygdala. Consistent with these findings, previous studies, using fear-potentiated startle (FPS), have shown exaggerated startle and deficits in fear inhibition in PTSD participants. However, many PTSD studies using the skin conductance response (SCR) report no group differences in fear acquisition. Method: The study included 41 participants with PTSD and 70 without PTSD. The fear conditioning session included a reinforced conditioned stimulus (CS+, danger cue) paired with an aversive airblast, and a nonreinforced conditioned stimulus (CS-, safety cue). Acoustic startle responses and SCR were acquired during the presentation of each CS. Results: The results showed that fear conditioned responses were captured in both the FPS and SCR measures. Furthermore, PTSD participants had higher FPS to the danger cue and safety cue compared to trauma controls. However, SCR did not differ between groups. Finally, we found that FPS to the danger cue predicted re-experiencing symptoms, whereas FPS to the safety cue predicted hyper-arousal symptoms. However, SCR did not contribute to PTSD symptom variance. Conclusions: Replicating earlier studies, we showed increased FPS in PTSD participants. However, although SCR was a good measure of differential conditioning, it did not differentiate between PTSD groups. These data suggest that FPS may be a useful tool for translational research.