title: Brain activation associated with changes in heart rate, heart rate variability, and plasma catecholamines during rectal distention.
abstract: OBJECTIVE
  To test the hypothesis that gut stimulation provokes autonomic arousal via activation of regional cerebral cortices. How the human brain processes interoceptive signals and forms initial autonomic arousal is one of the key questions to be answered in research on emotion.
  
  
  METHODS
  Twelve healthy males participated in this study. A barostat bag was inserted in the rectum and intermittently inflated with 0, 20, or 40 mm Hg at random for 80 seconds. H(2)(15)O positron emission tomography (PET) of the brain, electrocardiography, and blood sampling for catecholamines were performed. Changes in regional cerebral blood flow were interpreted using statistical parametric mapping.
  
  
  RESULTS
  Rectal distention with 40 mm Hg induced a significant increase in heart rate, low frequency (LF)/high frequency (HF) ratio of heart rate variability, and plasma adrenaline. Activated brain areas that were associated with increased heart rate during rectal distention were the right insula, right operculum, right dorsolateral prefrontal cortex, putamen, thalamus, periaqueductal gray, and cerebellum (p < .001, uncorrected), whereas those that were associated with an increased LF/HF ratio were the bilateral insula, putamen, thalamus, midbrain, pons, and cerebellum (p < .001, uncorrected). Activated brain areas that were associated with increased plasma adrenaline were the right insula, right orbitofrontal cortex, right parahippocampal gyrus, putamen, thalamus, periaqueductal gray, pons, and cerebellum (p < .001, uncorrected).
  
  
  CONCLUSIONS
  Our results suggest that the right insula and the related body mapping regions may form the functional module of sympathetic arousal in response to gut stimulation.
authors: Department of Behavioral Medicine, Tohoku University, Aoba, Sendai, Japan.
authors: Hideaki
authors: H
authors: Suzuki
authors: Satoshi
authors: S
authors: Watanabe
authors: Toyohiro
authors: T
authors: Hamaguchi
authors: Hirotaka
authors: H
authors: Mine
authors: Takahiro
authors: T
authors: Terui
authors: Motoyori
authors: M
authors: Kanazawa
authors: Noriko
authors: N
authors: Oohisa
authors: Mitsuya
authors: M
authors: Maruyama
authors: Tomoyuki
authors: T
authors: Yambe
authors: Masatoshi
authors: M
authors: Itoh
authors: Shin
authors: S
authors: Fukudo
mesh_terms: D001143:Arousal / Q000502:physiology*; D001341:Autonomic Nervous System / Q000502:physiology*; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D002395:Catecholamines / Q000097:blood*; D002404:Catheterization / Q000379:methods; D002531:Cerebellum / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology; D003071:Cognition / Q000502:physiology; D004562:Electrocardiography / Q000706:statistics & numerical data; D004644:Emotions / Q000502:physiology; D004837:Epinephrine / Q000097:blood; D007839:Functional Laterality / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data; D017397:Prefrontal Cortex / Q000502:physiology; D012007:Rectum / Q000294:innervation / Q000502:physiology*; D013788:Thalamus / Q000502:physiology
chemical_list: D002395:Catecholamines; D004837:Epinephrine