Μηχανισμοί ελέγχου της κινητικότητας του πεπτικού σωλήνα των εντόμων
The present dissertation aims to further investigate the mechanisms of mobility of the insect digestive tract and focuses specifically on its last part, the posterior intestine, the rectum and the anus. For this purpose, the larva of Zophobas morio, the largest member of the Coleoptera (beetles), wa...
| Main Authors: | , |
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | Greek |
| Published: |
Aristotle University Of Thessaloniki (AUTH)
2021
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10442/hedi/49915 https://doi.org/10.12681/eadd/49915 |
| Summary: | The present dissertation aims to further investigate the mechanisms of mobility of the insect digestive tract and focuses specifically on its last part, the posterior intestine, the rectum and the anus. For this purpose, the larva of Zophobas morio, the largest member of the Coleoptera (beetles), was selected to be studied, which includes beetles with a huge zoogeographical distribution, in almost every part of the planet except Antarctica. The correct interpretation of the mechanisms of control of the mobility of the digestive tract of insects requires first the understanding of its structure. The structure of the digestive tract was investigated and was found to consist of anterior, middle and posterior intestine. It is innervated by the last abdominal ganglion of the Central Nervous System by the four sub-branches. The study of the mechanical activity of the isolated digestive tract (ex vivo) of the larva of Zophobas morio includes the characterization of the patterns of contraction of the muscles fibers of the esophagus and the posterior intestine, rectum and anus. The electrophysiological study focused on the posterior intestine, and the presence of pacemaker muscle cells in the areas of the rectum and anus was detected. These areas present spontaneous myogenic contraction. The determination of the role of the CNS in the control of the myogenic rhythm of the pacemaker regions of the posterior intestine has been extensively investigated. The systems of motor neurons that innervate the rectum and anus were identified. Also, the neural networks driving these motor neurons were identified as rectum and anus central pattern generators (CPG) and they are located in the last abdominal ganglion. The role of the mechano-receptors related with the rectum and anus was investigated. It appears that this sensory information has an important role in the control of the rectum and anus motor neurons affecting the force of the intestinal contraction. Also, our electrophysiological results indicate that the output of the CPG ... |
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