Choline acetyltransferase-immunoreactive neurones in a prevertebral sympathetic ganglion, the inferior mesenteric ganglion.
Using immunohistochemical techniques a small population of choline acetyltransferase (ChAT) immunoreactive (IR) neurones has been identified in the inferior mesenteric ganglion (IMG) of guinea pig (4.6% of all neurones), ferret (6.4%) and rat (0.4%). A detailed study in the guinea-pig IMG revealed that the vast majority of cholinergic neurones did not express tyrosine hydroxylase (TH)-IR, indicating that they were non-catecholaminergic. The cholinergic neurones were significantly larger than the TH-positive neurones. The majority of the ChAT-IR cells (64%) was observed in small clusters which were consistently located in the caudal lobe of the IMG close to the entry of the hypogastric nerves. 83% of the ChAT-IR cells also contained neuropeptide Y (NPY). Since the vast majority of TH-negative cells were ChAT-positive (94%), the TH negativity was taken as an indirect indication for ChAT-IR. NPY-IR, somatostatin (SOM)-IR and vasoactive intestinal peptide (VIP)-IR were found in both the TH-IR cells (22, 84 and 1%, respectively) and the putative cholinergic population (95, 84 and 70, respectively). Thus the majority of cholinergic neurones in the IMG were likely to contain NPY, SOM and VIP. TH-IR cells exhibited an extensive innervation of fibers immunoreactive for ChAT, VIP, ENK and NOS. In contrast, only a sparse plexus of ChAT-, ENK-, NOS-, NPY- and SOM-positive fibres was found around the TH-negative cells. VIP-IR fibres did not appear to innervate ChAT neurones.
D000818:Animals; D002795:Choline O-Acetyltransferase / Q000276:immunology*; D005289:Ferrets; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008643:Mesentery / Q000201:enzymology*; D009474:Neurons / Q000276:immunology / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000201:enzymology*; D014446:Tyrosine 3-Monooxygenase / Q000276:immunology / Q000378:metabolism
D014446:Tyrosine 3-Monooxygenase; D002795:Choline O-Acetyltransferase