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Mucosa of the guinea pig gastric corpus is innervated by myenteric neurones with specific neurochemical coding and projection preferences

✍ Scribed by Reiche, Dania; Schemann, Michael


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
589 KB
Volume
410
Category
Article
ISSN
0021-9967

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✦ Synopsis


The present study identified and characterised myenteric neurones involved in the innervation of the gastric mucosa. We applied retrograde neuronal tracing methods by using the dye DiI (1,1Ј-didodecyl-3,3,3Ј,3Ј-tetramethylindocarbocyanine perchlorat) in combination with the immunohistochemical demonstration of choline acetyltransferase (ChAT), enkephalin (ENK), neuropeptide Y (NPY), nitric oxide synthase (NOS), substance P (SP), and vasoactive intestinal peptide (VIP). This method showed distinct neurochemical coding of DiI-labelled neurones with projections to the mucosa (mucosa neurones): ChAT/Ϫ (indicating the presence of ChAT only, 32%), ChAT/NPY/ϮVIP (22%), NOS/NPY/ϮVIP (19%), ChAT/SP/ϮENK (12%), NOS/Ϫ (indicating the presence of NOS only, 8%), or ChAT/ENK (4.6%). DiI-labelled mucosa neurones did not contain calretinin, serotonin, or somatostatin. All ChAT populations had primarily ascending projections, whereas the NOS populations had mainly descending projections. Both were further classified as longitudinally and circumferentially projecting neurones, the latter having projection preferences towards the lesser or greater curvature. All subpopulations exhibited projection preferences. Nitrergic projections primarily arose from cell bodies located at the lesser curvature. ChAT/Ϫ projections, which dominated the cholinergic pathway, mainly arose from cell bodies located at the greater curvature. The other major cholinergic pathway with the code ChAT/NPY/ϮVIP consisted of neurones located mainly at the lesser curvature. The results suggest specific coding of gastric myenteric neurones with projections to the mucosa. Polarised projections consisted of ascending cholinergic and descending nitrergic neurones; the additional presence of NPY/VIP was a prominent feature in both pathways. Chemical coding, polarity, and projection preferences of enteric pathways to the gastric mucosa are remarkably different from those of other regions in the gut.