title: Ontogeny of choline acetyltransferase (ChAT) immunoreactivity in the brain of the urodele amphibian Pleurodeles waltl.
abstract: The ontogeny of cholinergic neurons has been studied in the brain of the urodele amphibian Pleurodeles waltl by means of choline acetyltransferase (ChAT) immunohistochemistry. Embryonic and larval stages were studied. The earliest ChAT immunoreactive (ChATi) cells were the primary motoneurons in the upper spinal cord, at embryonic stage 29. Slightly later, before hatching, the cranial nerve motor nuclei were immunopositive as well as non-motor populations in the developing inferior reticular nucleus, the nucleus of the solitary tract, the dorsal column nucleus and the retina. At initial larval stages, ChATi cells were located for the first time in the suprachiasmatic nucleus and the isthmic tegmentum. In addition, moderate immunoreactivity appeared in the Mauthner cells. During the period of active larval life the cholinergic systems maturated progressively and new ChATi cell groups were found in the caudal telencephalon and the habenula. Also extensive fiber labeling occurred at active larval stages. No transient ChAT expression was observed and even the Mauthner cells maintained their immunoreactivity after metamorphosis. A general caudorostral spatio-temporal sequence of appearance of cholinergic structures was found in the brain. Comparison of the results observed in the urodele with previous data available only in amniotes shows numerous similarities and suggests a conservative developmental pattern of cholinergic systems in vertebrates.
authors.affiliation: Departamento de Biología Celular, Facultad de Biología, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors.forename: Jesús M
authors.initials: JM
authors.lastname: López
authors.forename: Nerea
authors.initials: N
authors.lastname: Moreno
authors.forename: Agustín
authors.initials: A
authors.lastname: González
mesh_terms: D000375:Aging; D000818:Animals; D001921:Brain / Q000196:embryology / Q000201:enzymology* / Q000254:growth & development; D002795:Choline O-Acetyltransferase / Q000378:metabolism*; D004625:Embryo, Nonmammalian; D005306:Fertilization; D007150:Immunohistochemistry; D007814:Larva; D010999:Pleurodeles; D012160:Retina / Q000196:embryology / Q000201:enzymology / Q000254:growth & development
chemical_list: D002795:Choline O-Acetyltransferase