Infection-induced viscerosensory signals from the gut enhance anxiety: implications for psychoneuroimmunology

Brain Behav Immun. 2007 Aug;21(6):721-6. doi: 10.1016/j.bbi.2007.02.005. Epub 2007 Apr 10.


Infection and inflammation lead to changes in mood and cognition. Although the "classic" sickness behavior syndrome, involving fatigue, social withdrawal, and loss of appetites are most familiar, other emotional responses accompany immune activation, including anxiety. Recent studies have shown that gastrointestinal bacterial infections lead to enhanced anxiety-like behavior in mice. The bacteria-induced signal is most likely carried by vagal sensory neurons, and occurs early on (within 6h) during the infection. These signals induce evidence of activation in brain regions that integrate viscerosensory information with mood, and potentiate activation in brain regions established as key players in fear and anxiety. The findings underline the importance of viscerosensory signals arising from the gastrointestinal tract in modulation of behaviors appropriate for coping with threats, and suggest that these signals may contribute to affective symptoms associated with gastrointestinal disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Anxiety / complications
  • Anxiety / immunology*
  • Bacterial Infections / complications
  • Bacterial Infections / immunology
  • Bacterial Infections / psychology
  • Brain / physiology*
  • Ganglia, Autonomic / physiology
  • Gastrointestinal Diseases / complications
  • Gastrointestinal Diseases / immunology*
  • Gastrointestinal Diseases / psychology
  • Gastrointestinal Tract / immunology
  • Gastrointestinal Tract / innervation
  • Homeostasis / immunology
  • Humans
  • Infections / complications
  • Infections / immunology*
  • Mice
  • Neuroimmunomodulation / physiology
  • Psychoneuroimmunology*
  • Vagus Nerve / physiology