Early‐life stress selectively affects gastrointestinal but not behavioral responses in a genetic model of brain–gut axis dysfunction. Issue 1 (2nd December 2014)

• Record Type: Journal Article
• Authors: Hyland, N. P.; O'Mahony, S. M.; O'Malley, D.; O'Mahony, C. M.; Dinan, T. G.; Cryan, J. F.
• Is Part Of: Neurogastroenterology & motility. Volume 27:Issue 1(2015:Jan.)
• Page Start: 105
• Page End: 113
• Publication Date: 2014-12-02
• Subjects: Gastrointestinal system -- Motility -- Periodicals; Gastrointestinal system -- Innervation -- Periodicals; 616.33
• DOI: 10.1111/nmo.12486
• Languages: English
• ISSNs: 1350-1925

Abstract

<abstract abstract-type="main" id="nmo12486-abs-0001"> <title>Abstract</title> <sec id="nmo12486-sec-0001" sec-type="section"> <title>Background</title> <p>Early‐life stress and a genetic predisposition to display an anxiety‐ and depressive‐like phenotype are associated with behavioral and gastrointestinal (GI) dysfunction. Animals exposed to early‐life stress, and those genetically predisposed to display anxiety or depressive behaviors, have proven useful tools in which to study stress‐related GI disorders, such as irritable bowel syndrome (IBS). IBS is a heterogeneous disorder, and likely a consequence of both genetic and environmental factors. However, the combined effects of early‐life stress and a genetic predisposition to display anxiety‐ and depression‐like behaviors on GI function have not been investigated.</p> </sec> <sec id="nmo12486-sec-0002" sec-type="section"> <title>Methods</title> <p>We assessed the effect of maternal separation (MS) on behavioral and GI responses in WKY animals relative to a normo‐anxious reference strain.</p> </sec> <sec id="nmo12486-sec-0003" sec-type="section"> <title>Key Results</title> <p>Both non‐separated (NS) WKY and WKY‐MS animals displayed anxiety‐like responses in the open‐field test and depressive‐like behaviors in the forced swim test relative to Sprague–Dawley rats. However, MS had no further influence on anxiety‐ and depressive‐like behaviors exhibited by this stress‐prone rat strain. Similarly, corticosterone levels measured after the OFT were insensitive to MS in WKY animals. However, WKY‐MS displayed significantly increased colonic visceral hypersensitivity, fecal output, and altered colonic cholinergic sensitivity.</p> </sec> <sec id="nmo12486-sec-0004" sec-type="section"> <title>Conclusions & Inferences</title> <p>Our data suggest that early‐life stress, on the background of a genetic predisposition to display an anxiety‐ and depressive‐like phenotype, selectively influences GI function rather than stress‐related behaviors. Thus, our findings highlight the importance of genetic predisposition on the outcome of early‐life adversity on GI function.</p> </sec> </abstract>