title: Confocal imaging of autonomic preganglionic neurons in the spinal cord of the caecilian Typhlonectes natans (Amphibia: Gymnophiona).
abstract: Little is known about the spinal sympathetic organization in the caecilian amphibians. We examined for the first time the location of sympathetic preganglionic neurons (SPNs) in the spinal cord using a panel of specific markers expressed in SPNs. The SPNs of anuran amphibians form two cell columns segregated mainly in the lateral and medial marginal areas of the central gray matter. In the caecilian Typhlonectes natans immunoreactivity for galanin and ChAT is found in most laterally arranged neurons lying in spinal segments 2-7. They are encircled by TH- and nNOS-immunoreactive nerve fibers. These neurons might project specifically to a population of adrenergic sympathetic postganglionic neurons in paravertebral ganglia and/or non-adrenergic sympathetic postganglionic neurons in the celiac ganglia. However the segmental restriction and target specificity of the neurons of the species studied are not known. As mucous and granular glands in the dermis may represent one of the peripheral targets of the adrenergic ganglion cells and reflect the prominent preganglionic cell columns, an immunohistochemical study was done also on these glands. Retrograde-tracing studies are, however, needed to study the segmental localization of the preganglionic neurons and their projections to the postganglionic neurons in sympathetic ganglia.
authors.affiliation: Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy. Electronic address: dzaccone@unime.it.
authors.forename: Daniele
authors.initials: D
authors.lastname: Zaccone
authors.affiliation: Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy. Electronic address: elauriano@unime.it.
authors.forename: Eugenia Rita
authors.initials: ER
authors.lastname: Lauriano
authors.affiliation: Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy. Electronic address: gcapillo@unime.it.
authors.forename: Gioele
authors.initials: G
authors.lastname: Capillo
authors.affiliation: Department of Comparative Anatomy, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Krakow, Poland. Electronic address: krystyna.zuwala@uj.edu.pl.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Zuwała
authors.affiliation: Department of Comparative Anatomy, Institute of Zoology, Jagiellonian University, Gronostajowa 9, 30-387 Krakow, Poland. Electronic address: karolina.budzik@uj.edu.pl.
authors.forename: Karolina Agata
authors.initials: KA
authors.lastname: Budzik
authors.affiliation: Poison Information Centre, Jagiellonian University Medical College, Śniadeckich 10, 31-531 Krakow, Poland. Electronic address: michalkuciel@gmail.com.
authors.forename: Michał
authors.initials: M
authors.lastname: Kuciel
authors.affiliation: Department of Environmental Sciences, Territorial, Food and Health Security (S.A.S.T.A.S.), University of Messina, Viale F. Stagno d'Alcontres 31, I-98166 Messina, Italy. Electronic address: gzaccone@unime.it.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Zaccone
mesh_terms: D000663:Amphibians / Q000378:metabolism*; D000818:Animals; D005728:Ganglia, Sympathetic / Q000166:cytology; D007150:Immunohistochemistry; D018613:Microscopy, Confocal / Q000379:methods*; D009474:Neurons / Q000166:cytology*; D013116:Spinal Cord / Q000166:cytology*
keywords: Caecilian amphibians; Confocal microscopy; Sympathetic preganglionic neurons