title: Contributions of developmental studies in the dogfish Scyliorhinus canicula to the brain anatomy of elasmobranchs: insights on the basal ganglia.
abstract: The basic anatomy of the elasmobranch brain has been previously established after studying the organization of the different subdivisions in the adult brain. However, despite the relatively abundant immunohistochemical and hodologic studies performed in different species of sharks and skates, the organization of some brain subdivisions remains unclear. The present study focuses on some brain regions in which subdivisions established on the basis of anatomical data in adults remain controversial, such as the subpallium, mainly the striatal subdivision. Taking advantage of the great potential of the lesser spotted dogfish, Scyliorhinus canicula, as a model for developmental studies, we have characterized the subpallium throughout development and postembryonic stages by analyzing the distribution of immunomarkers for GABA, catecholamines, and neuropeptides, such as substance P. Moreover, we have analyzed the expression pattern of regulatory genes involved in the regionalization of the telencephalon, such as Dlx2, Nkx2.1, and Shh, and followed their derivatives throughout development in relation to the distribution of such neurochemical markers. For further characterization, we have also analyzed the patterns of innervation of the subpallium after applying tract-tracing techniques. Our observations may shed light on postulate equivalences of regions and nuclei among elasmobranchs and support homologies with other vertebrates.
authors.affiliation: Department of Cell Biology and Ecology, CIBUS, University of Santiago de Compostela, Spain.
authors.forename: Idoia
authors.initials: I
authors.lastname: Quintana-Urzainqui
authors.forename: Catalina
authors.initials: C
authors.lastname: Sueiro
authors.forename: Ivan
authors.initials: I
authors.lastname: Carrera
authors.forename: Susana
authors.initials: S
authors.lastname: Ferreiro-Galve
authors.forename: Gabriel
authors.initials: G
authors.lastname: Santos-Durán
authors.forename: Sol
authors.initials: S
authors.lastname: Pose-Méndez
authors.forename: Sylvie
authors.initials: S
authors.lastname: Mazan
authors.forename: Eva
authors.initials: E
authors.lastname: Candal
authors.forename: Isabel
authors.initials: I
authors.lastname: Rodríguez-Moldes
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001479:Basal Ganglia / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D001931:Brain Mapping; D002395:Catecholamines / Q000378:metabolism; D004284:Dogfish / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development; D004625:Embryo, Nonmammalian; D005136:Eye Proteins / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D005968:Glutamate Decarboxylase / Q000378:metabolism; D053823:Hedgehog Proteins / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D002395:Catecholamines; C088334:Distal-less homeobox proteins; D005136:Eye Proteins; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D009479:Neuropeptides; D009687:Nuclear Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D005680:gamma-Aminobutyric Acid; D014446:Tyrosine 3-Monooxygenase; D005968:Glutamate Decarboxylase