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Enteric glial cells are associated with stress‐induced colonic hyper‐contraction in maternally separated rats
Author(s) -
Fujikawa Y.,
Tominaga K.,
Tanaka F.,
Tanigawa T.,
Watanabe T.,
Fujiwara Y.,
Arakawa T.
Publication year - 2015
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.12577
Subject(s) - myenteric plexus , contraction (grammar) , irritable bowel syndrome , enteric nervous system , glial fibrillary acidic protein , endocrinology , medicine , pathophysiology , pathogenesis , chronic stress , cholinergic , chemistry , immunohistochemistry
Abstract Background Enteric glial cells ( EGC s) play important roles in enteric integrity and regulation of gastrointestinal function. However, whether EGC s undergo pathophysiological changes in stress‐associated gastrointestinal disorders is unknown. We investigated structural and functional alterations in colonic EGC s and their roles in colonic contraction in an irritable bowel syndrome ( IBS ) model. Methods As a chronic stress, male Wistar rats underwent 3‐h maternal separation during postnatal days 2–14. As an acute stress, we used water‐immersion stress (4 h) in adulthood (at 8 weeks). We quantitatively and morphologically evaluated enteric neurons and EGC s using whole‐mount longitudinal muscle‐myenteric plexus preparations. Colonic contraction was analyzed with electrical field stimulation ( EFS ). Key Results Glial fibrillary acidic protein ( GFAP ) expression and the number of total, cholinergic, and nitrergic neurons were unchanged in maternally separated rats with acute stress (combined stress: an IBS model) compared with controls. However, the density of GFAP ‐positive EGC processes that apparently overlapped with the neurons and the extent of bulbous swelling of terminals increased according to the stress intensity: control, acute stress, maternal separation, and combined stress. EFS ‐induced colonic contractions were significantly greater in the combined stress rats than in controls. Higher dose of fluorocitrate, a selective inhibitor of EGC metabolism, was required to inhibit both EFS ‐induced contraction and EGC s activation in the combined stress rats than in controls. Conclusions & Inferences Colonic EGC s exhibited structural alterations according to the stress intensity. EGC s were associated with stress‐induced colonic hyper‐contraction in the combined stress rats, which may underlie the pathogenesis of IBS .