Neural correlates of fear-induced sympathetic response associated with the peripheral temperature change rate.
Activation of the sympathetic nervous system is essential for coping with environmental stressors such as fearful stimuli. Recent human imaging studies demonstrated that activity in some cortical regions, such as the anterior cingulate cortex (ACC) and anterior insula cortex (aIC), is related to sympathetic activity. However, little is known about the functional brain connectivity related to sympathetic response to fearful stimuli. The participants were 32 healthy, right-handed volunteers. Functional magnetic resonance imaging (fMRI) was used to examine brain activity when watching horror and control movies. Fingertip temperature was taken during the scanning as a measure of sympathetic response. The movies were watched a second time, and the degree of fear (9-point Likert-type scale) was evaluated every three seconds. The brain activity of the ACC, bilateral aIC, and bilateral anterior prefrontal cortex (aPFC) was correlated with the change rate of fingertip temperature, with or without fearful stimuli. Functional connectivity analysis revealed significantly greater positive functional connectivity between the amygdala and the ACC and between the amygdala and the aIC when watching the horror movie than when watching the control movie. Whole-brain psycho-physiological interaction (PPI) analysis revealed that the functional connectivity between the left amygdala and the ACC was modulated according to the fear rating. Our results indicate that the increased functional connectivity between the left amygdala and the ACC represents a sympathetic response to fearful stimuli.
Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan. Electronic address: kyoshiha@cephal.med.kyushu-u.ac.jp.
Kazufumi
K
Yoshihara
Division of Cerebral Integration, Department of Cerebral Research, National Institute for Physiological Sciences, 38 Myodaiji-Nishigonaka, Okazaki 444-8585, Japan; Department of Psychology, Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan.
Hiroki C
HC
Tanabe
Division of Cerebral Integration, Department of Cerebral Research, National Institute for Physiological Sciences, 38 Myodaiji-Nishigonaka, Okazaki 444-8585, Japan; Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10, Higashiogu, Arakawa, Tokyo 116-8551, Japan.
Hiroaki
H
Kawamichi
Division of Cerebral Integration, Department of Cerebral Research, National Institute for Physiological Sciences, 38 Myodaiji-Nishigonaka, Okazaki 444-8585, Japan.
Takahiko
T
Koike
Research Center for Child Mental Development, National University Corporation University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui 910-1193, Japan.
Mika
M
Yamazaki
Department of Psychosomatic Medicine, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashiku, Fukuoka 812-8582, Japan.
Nobuyuki
N
Sudo
Division of Cerebral Integration, Department of Cerebral Research, National Institute for Physiological Sciences, 38 Myodaiji-Nishigonaka, Okazaki 444-8585, Japan; Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki 444-8585, Japan.
Norihiro
N
Sadato
D000328:Adult; D000679:Amygdala / Q000502:physiology; D001831:Body Temperature; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D005239:Fear / Q000502:physiology*; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D017397:Prefrontal Cortex / Q000502:physiology; D013564:Sympathetic Nervous System; D055815:Young Adult
Cingulate; Fear; Insula; Peripheral temperature; Sympathetic; fMRI