Immunohistochemical study on the rabbit intestinal nervous system involved in soft feces formation and transportation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K08121
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Integrative animal science
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Shibata Hideshi 東京農工大学, (連合)農学研究科(研究院), 教授 (50145190)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 大腸 / ウサギ / 腸神経系 / 腸壁 / 構造

Outline of Final Research Achievements

The present study clarified the structural features of the wall and nervous tissues in each segment of the rabbit large intestine. The fusus coli and rectum have the thickest intestinal wall, followed by the proximal colon and distal colon, and the cecum has the thinnest wall. The fusus coli has the thickest mucosa whereas the rectum has the thickest muscular layer. Furthermore, the fusus coli has the most numerous mucous cells whereas the cecum has the fewest. The enteric nervous tissue is the richest in the proximal colon, followed by the fusus coli, distal colon, and cecum. Some neurochemical substances are distributed in a similar fashion. These findings suggest that the proximal colon may control complex bowel motility with the most well-developed neuronal network, the fusus coli may secrete rich mucus that enwraps the soft feces, and the cecum may gently contract for fermentation of the cecal contents with the least developed wall and nerve plexus.

Free Research Field

獣医解剖学

Academic Significance and Societal Importance of the Research Achievements

本研究によって，盲腸糞の形成という特異な消化機構を有するウサギにおける大腸壁の構築と腸管運動を制御する腸神経系の構築が明らかになった．これらの結果は，近年，伴侶動物として飼育数が増加しているウサギに多発する消化管疾患の治療法の開発においても，その基盤となる基礎獣医学的知見となった．