Polarised innervation pattern of the mucosa of the guinea pig distal colon.
A neuronal retrograde tracing method with the dye DiI in combination with the immunohistochemical detection of vasoactive intestinal polypeptide (VIP) and choline acetyltransferase (ChAT) was used to characterise the mucosal projection of neurones located in the submucosal plexus of the guinea pig distal colon. VIP and ChAT immunoreactivity labelled separate populations. The mucosa was innervated by descending (59.7 +/- 7.4%), ascending (8.7 +/- 5.0%) and circumferential (31.7 +/- 6.1%) pathways. Descending neurones had longer projections than ascending ones. Descending DiI-labelled neurones were in their vast majority VIP-positive (88.4 +/- 3.6%) and only 3.5 +/- 4.8% of them were ChAT-positive. Conversely, the ascending pathways were predominantly ChAT-positive (90.9 +/- 20.3%) and only 7.8 +/- 20.6% of them were VIP-positive. A significantly larger proportion of DiI-neurones with circumferential projection were ChAT- than VIP-positive (70.9 +/- 15.6 vs. 27.8 +/- 15.7%). The proportion of ascending, descending and circumferential ChAT-positive DiI-neurones was 23:7:70%, respectively, whereas the proportion for VIP-positive DiI-neurones was 2:84:14%, respectively. The results suggest a conservation of the submucosal innervation pattern along the guinea pig colonic mucosa but also reveal differences in the mucosal enteric innervation of other regions of the gastrointestinal tract.
Neunlist
M
M
Department of Physiology, School of Veterinary Medicine, Hannover, Germany.
Schemann
M
M
D000818:Animals; D002452:Cell Count; D002795:Choline O-Acetyltransferase / Q000032:analysis; D003106:Colon / Q000166:cytology*; D006168:Guinea Pigs; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology; D007413:Intestinal Mucosa / Q000166:cytology* / Q000294:innervation*; D009474:Neurons / Q000145:classification / Q000166:cytology; D009475:Neurons, Afferent / Q000166:cytology; D009476:Neurons, Efferent / Q000166:cytology; D013368:Submucous Plexus / Q000166:cytology; D014660:Vasoactive Intestinal Peptide / Q000032:analysis
D014660:Vasoactive Intestinal Peptide; D002795:Choline O-Acetyltransferase