Anterior cingulate activity to salient stimuli is modulated by autonomic arousal in posttraumatic stress disorder.
Reduced ventral anterior cingulate (vACC) activity to threat is thought to reflect an impairment in regulating arousal networks in posttraumatic stress disorder (PTSD). Concurrent functional magnetic resonance imaging (fMRI) and skin conductance response (SCR) recording were used to examine neural functioning when arousal networks are engaged. Eleven participants with PTSD and 11 age- and sex-matched non-traumatized controls performed an oddball task that required responding to salient, non-trauma-related auditory target tones embedded in lower frequency background tones. Averaged target-background analyses revealed significantly greater dorsal ACC, supramarginal gyrus, and hippocampal activity in PTSD relative to control participants.With-SCR target responses resulted in increased vACC activity in controls, and dorsal ACC activity in PTSD. PTSD participants had reduced vACC activity relative to controls to target tones when SCR responses were present. This reduction in vACC in PTSD relative to controls was not apparent in without-SCR responses. These findings suggest that a reduction in vACC in PTSD occurs specifically when arousal networks are engaged.
Felmingham
Kim L
KL
The Brain Dynamics Centre, Westmead Millenium Institute & Western Clinical School, University of Sydney, Westmead Hospital, NSW 2145, Australia. kim_felmingham@wmi.usyd.edu.au
Williams
Leanne M
LM
Kemp
Andrew H
AH
Rennie
Chris
C
Gordon
Evian
E
Bryant
Richard A
RA
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D000368:Aged; D001143:Arousal; D001921:Brain / Q000503:physiopathology; D016022:Case-Control Studies; D005239:Fear / Q000523:psychology; D005260:Female; D007839:Functional Laterality; D005712:Galvanic Skin Response; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008016:Life Change Events; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology* / Q000523:psychology*