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Stress increases descending inhibition in mouse and human colon
Author(s) -
Reed D. E.,
Zhang Y.,
Beyak M. J.,
Lourenssen S.,
Blennerhassett M. G.,
Paterson W. G.,
Vanner S. J.
Publication year - 2016
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1111/nmo.12755
Subject(s) - distension , myenteric plexus , stimulation , endocrinology , medicine , hormone , irritable bowel syndrome , chronic stress , inhibitory postsynaptic potential , chemistry , immunohistochemistry
Abstract Background A relationship between stress and the symptoms of irritable bowel syndrome ( IBS ) has been well established but the cellular mechanisms are poorly understood. Therefore, we investigated effects of stress and stress hormones on colonic descending inhibition and transit in mouse models and human tissues. Methods Stress was applied using water avoidance stress ( WAS ) in the animal model or mimicked using stress hormones, adrenaline (5 nM), and corticosterone (1 μ M). Intracellular recordings were obtained from colonic circular smooth muscle cells in isolated smooth muscle/myenteric plexus preparations and the inhibitory junction potential ( IJP ) was elicited by nerve stimulation or balloon distension oral to the site of recording. Key Results Water avoidance stress increased the number of fecal pellets compared to control ( p < 0.05). WAS also caused a significant increase in IJP amplitude following balloon distension. Stress hormones also increased the IJP amplitude following nerve stimulation and balloon distension ( p < 0.05) in control mice but had no effect in colons from stressed mice. No differences were observed with application of ATP between stress and control tissues, suggesting the actions of stress hormones were presynaptic. Stress hormones had a large effect in the nerve stimulated IJP in human colon (increased >50%). Immunohistochemical studies identified alpha and beta adrenergic receptor immunoreactivity on myenteric neurons in human colon. Conclusions & Inferences These studies suggest that WAS and stress hormones can signal via myenteric neurons to increase inhibitory neuromuscular transmission. This could lead to greater descending relaxation, decreased transit time, and subsequent diarrhea.