Abstract
Viscerofugal neurons in the myenteric plexus project out of the gut to the sympathetic neurons of the prevertebral ganglia and form the afferent arm of the intestino-intestinal inhibitory reflexes. In this study, we retrogradely labelled viscerofugal neurons in the middle and distal colon, and rectum which project to or through the inferior mesenteric ganglion and major pelvic ganglia. We found that 57–81 % of these neurons contained immunoreactivity to calbindin, 37–70% contained immunoreactivity to bombesin, and 22–37% contained immunoreactivity to nitric oxide synthase, irrespective of the ganglion to which they projected. However, only 0–12% of viscerofugal neurons labelled in the rectum from the inferior mesenteric ganglion or intermesenteric nerves contained immunoreactivity to vasoactive intestinal peptide (VIP). In contrast, about 45% of viscerofugal neurons labelled from the pelvic ganglia contained VIP. We also have utilised immunoreactivity to bombesin to demonstrate, for the first time, the presence of viscerofugal terminals surrounding some sympathetic neurons in the major pelvic ganglia. The enteric origin of these terminals was confirmed by their degeneration following severance of the connections between the pelvic ganglia and the lower bowel. Our observation that some pelvic neurons receive viscerofugal input suggests that they can integrate peripheral and central messages. However, the majority of pelvic neurons do not receive viscerofugal input and would be predicted simply to relay central messages.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.