The Irritable Bowel Syndrome: How Stress Can Affect the Amygdala Activity and the Brain-Gut Axis

Abstract

The ANS is composed of the sympathetic (i.e. the splanchnic nerves) and parasympathetic nervous system (i.e. the vagus nerves and the sacral parasympathetic nucleus represented by the pelvic nerves) which are mixed systems.

Brain responses to uncertainty about upcoming rectal discomfort in quiescent Crohn's disease – a fMRI study

“…The amygdala, like the cingulate cortex, is involved in assigning emotional significance to environmental information and triggering adaptive physiological, behavioral, and affective responses . A large body of literature identifies the amygdala as a detector of potential threats, and a mediator of adaptive fear responses with a bias toward negative information .…”

Stress-Induced Visceral Pain: Toward Animal Models of Irritable-Bowel Syndrome and Associated Comorbidities

“…Numerous other pathways and systems feed into this complex network of communication, including the stress axis and immune system. The role of the amygdala in IBS has been extensively reviewed in the context of brain–gut axis communication ( 146 ) and numerous clinical and preclinical trials have also highlighted an important contribution of the amygdala to visceral pain processing and IBS ( 52 , 147 , 148 ). Here, we discuss the pathophysiology of visceral pain in terms of signaling along the microbiota–brain–gut axis, the hypothalamic–pituitary–adrenal (HPA) axis, and the immune system.…”

The Relationship Between Irritable Bowel Syndrome , Depression , Anxiety, and Stress among a Sample of Irritable Bowel Patients - Predictive Study

“…Extra-intestinal manifestations are also frequently described by the patients (e.g. headache, low back pain, chronic fatigue, interstitial cystitis…) (Bonaz et al 2012 The fact that so many people with IBS have anxiety and depression has led many to speculate that IBS is primarily a psychological, not a physical, disorder. However, the condition is complex and most likely results from an interplay between psychological and biological factors.…”

“…At the central level, stress inhibits the parasympathetic nervous system and activates the sympathetic nervous system through the effect of PVN projections on the DMNV and intermediolateral column cells of the spinal cord. ( Bonaz et al 2012) Acute stress and emotional arousal may induce the change of the colonic motilities. Colonic motilities show exaggerated patterns when IBS patients are under the stress.…”