title: The simultaneous presence of neuroepithelial cells and neuroepithelial bodies in the respiratory gas bladder of the longnose gar, Lepisosteus osseus, and the spotted gar, L. oculatus.
abstract: Anatomical and functional studies on the autonomic innervation as well as the location of airway receptors in the air-bladder of lepisosteids are very fragmentary. These water-breathing fishes share in common with the bichirs the presence of a glottis (not a ductus pneumaticus) opening into the esophagus. In contrast to a high concentration of neuroepithelial cells (NECs) contained in the furrowed epithelium in the lung of Polypterus, these cells are scattered as solitary cells in the glottal epithelium, and grouped to form neuroepithelial bodies (NEBs) in the mucociliated epithelium investing the main trabeculae in the air-bladder of Lepisosteus osseus and L. oculatus. The present immunohistochemical studies also demonstrated the presence of nerve fibers in the trabecular striated musculature and a possible relation to NEBs in these species, and identified immunoreactive elements of this innervation. Tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), 5-HT and neuropeptide immunoreactivities were detected in the intramural nerve fibers. 5-HT and VIP immunopositive nerve fibers are apparently associated with NEBs. TH, VIP and SP immunoreactivities are also present in nerve fibers coursing in the radially arranged striated muscle surrounding the glottis and its submucosa. 5-HT positive neurons are also found in submucosal and the muscle layers of the glottis. The physiological function of the adrenergic and inhibitory innervation of the striated muscle as well as the neurochemical coding and morphology of the innervation of the NEBs are not known. Future studies are needed to provide evidence for these receptors with the capacity of chemoreceptors and/or mechanoreceptors.
authors.affiliation: Department of Animal Biology and Marine Ecology, Faculty of Science, University of Messina, Italy. zacconed@unime.it
authors.forename: Daniele
authors.initials: D
authors.lastname: Zaccone
authors.forename: Konrad
authors.initials: K
authors.lastname: Dabrowski
authors.forename: Eugenia Rita
authors.initials: ER
authors.lastname: Lauriano
authors.forename: Angela
authors.initials: A
authors.lastname: de Pasquale
authors.forename: Daniele
authors.initials: D
authors.lastname: Macrì
authors.forename: Leszek
authors.initials: L
authors.lastname: Satora
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lanteri
mesh_terms: D000818:Animals; D002795:Choline O-Acetyltransferase / Q000096:biosynthesis; D005399:Fishes / Q000033:anatomy & histology*; D007150:Immunohistochemistry; D009092:Mucous Membrane / Q000378:metabolism / Q000648:ultrastructure; D054792:Muscle, Striated / Q000033:anatomy & histology / Q000294:innervation; D009412:Nerve Fibers / Q000378:metabolism / Q000648:ultrastructure; D046568:Neuroepithelial Bodies / Q000378:metabolism / Q000648:ultrastructure*; D046569:Neuroepithelial Cells / Q000378:metabolism / Q000648:ultrastructure*; D009479:Neuropeptides / Q000096:biosynthesis; D012137:Respiratory System / Q000033:anatomy & histology / Q000294:innervation; D012701:Serotonin / Q000096:biosynthesis; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis
chemical_list: D009479:Neuropeptides; D012701:Serotonin; D014446:Tyrosine 3-Monooxygenase; D002795:Choline O-Acetyltransferase