title: Enteric plexuses of two choline-acetyltransferase transgenic mouse lines: chemical neuroanatomy of the fluorescent protein-expressing nerve cells.
abstract: We studied cholinergic circuit elements in the enteric nervous system (ENS) of two distinct transgenic mouse lines in which fluorescent protein expression was driven by the choline-acetyltransferase (ChAT) promoter. In the first mouse line, green fluorescent protein was fused to the tau gene. This construct allowed the visualization of the fiber tracts and ganglia, however the nerve cells were poorly resolved. In the second mouse line (ChATcre-YFP), CRE/loxP recombination yielded cytosolic expression of yellow fluorescent protein (YFP). In these preparations the morphology of enteric neurons could be well studied. We also determined the neurochemical identity of ENS neurons in muscular and submucous layers using antibodies against YFP, calretinin (CALR), calbindin (CALB), and vasoactive intestinal peptide (VIP). Confocal microscopic imaging was used to visualize fluorescently-conjugated secondary antibodies. In ChATcre-YFP preparations, YFP was readily apparent in somatodendritic regions of ENS neurons. In the myenteric plexus, YFP/CALR/VIP staining revealed that 34% of cholinergic cells co-labeled with CALR. Few single-stained CR-positive cells were observed. Neither YFP nor CALR co-localized with VIP. In GFP/CALB/CALR staining, all co-localization combinations were represented. In the submucosal plexus, YFP/CALR/VIP staining revealed discrete neuronal populations. However, in separate preparations, double labeling was observed for YFP/CALR and CALR/VIP. In YFP/CALR/CALB staining, all combinations of double staining and triple labeling were verified. In conclusion, the neurochemical coding of ENS neurons in these mouse lines is consistent with many observations in non-transgenic animals. Thus, they provide useful tools for physiological and pharmacological studies on distinct neurochemical subtypes of ENS neurons.
authors.affiliation: Institute of Sport Sciences and Physical Education, University of Pécs, Pécs, Hungary.
authors.forename: Márta
authors.initials: M
authors.lastname: Wilhelm
authors.affiliation: COBRE Center for Structural and Functional Neuroscience; Department of Biomedical Sciences, University of Montana, Missoula, Montana, USA.
authors.forename: J Josh
authors.initials: JJ
authors.lastname: Lawrence
authors.affiliation: Department of Experimental Zoology and Neurobiology, University of Pécs, Pécs, Hungary. Electronic address: gabriel@gamma.ttk.pte.hu.
authors.forename: Robert
authors.initials: R
authors.lastname: Gábriel
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis; D064032:Calbindin 2 / Q000032:analysis; D064026:Calbindins / Q000032:analysis; D002795:Choline O-Acetyltransferase / Q000032:analysis*; D059329:Cholinergic Neurons / Q000378:metabolism; D017615:Enteric Nervous System / Q000166:cytology* / Q000378:metabolism*; D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins / Q000032:analysis; D007150:Immunohistochemistry / Q000379:methods*; D008164:Luminescent Proteins / Q000032:analysis; D051379:Mice; D008822:Mice, Transgenic; D056347:Neuroanatomical Tract-Tracing Techniques / Q000379:methods*; D009474:Neurons / Q000166:cytology* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014660:Vasoactive Intestinal Peptide / Q000032:analysis; D016875:tau Proteins / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D064032:Calbindin 2; D064026:Calbindins; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; C558298:Mapt protein, mouse; D016875:tau Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins; D014660:Vasoactive Intestinal Peptide; D002795:Choline O-Acetyltransferase
keywords: Calcium-binding proteins; Cholinergic neuron; Enteric motoneurons; Green and yellow fluorescent protein; Vasoactive intestinal polypeptide