title: Gustatory and general visceral centers and their connections in the brain of adult zebrafish: a carbocyanine dye tract-tracing study.
abstract: The central connections of the gustatory/general visceral system of the adult zebrafish (Danio rerio) were examined by means of carbocyanine dye tracing. Main primary gustatory centers (facial and vagal lobes) received sensory projections from the facial and vagal nerves, respectively. The vagal nerve also projects to the commissural nucleus of Cajal, a general visceral sensory center. These primary centers mainly project on a prominent secondary gustatory and general visceral nucleus (SGN/V) located in the isthmic region. Secondary projections on the SGN/V were topographically organized, those of the facial lobe mainly ending medially to those of the vagal lobe, and those from the commissural nucleus ventrolaterally. Descending facial lobe projections to the medial funicular nucleus were also noted. Ascending fibers originating from the SGN/V mainly projected to the posterior thalamic nucleus and the lateral hypothalamus (lateral torus, lateral recess nucleus, hypothalamic inferior lobe diffuse nucleus) and an intermediate cell- and fiber-rich region termed here the tertiary gustatory nucleus proper, but not to a nucleus formerly considered as the zebrafish tertiary gustatory nucleus. The posterior thalamic nucleus, tertiary gustatory nucleus proper, and nucleus of the lateral recess gave rise to descending projections to the SGN/V and the vagal lobe. The connectivity between diencephalic gustatory centers and the telencephalon was also investigated. The present results showed that the gustatory connections of the adult zebrafish are rather similar to those reported in other cyprinids, excepting the tertiary gustatory nucleus. Similarities between the gustatory systems of zebrafish and other fishes are also discussed. J. Comp. Neurol. 525:333-362, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Cell and Molecular Biology, Faculty of Sciences, University of A Coruña, A Coruña, Spain.|Neurover Group, Centro de Investigaciones Científicas Avanzadas (CICA), University of A Coruña, A Coruña, Spain.
authors.forename: Julián
authors.initials: J
authors.lastname: Yáñez
authors.affiliation: Department of Cell and Molecular Biology, Faculty of Sciences, University of A Coruña, A Coruña, Spain.
authors.forename: Yara
authors.initials: Y
authors.lastname: Souto
authors.affiliation: Department of Cell and Molecular Biology, Faculty of Sciences, University of A Coruña, A Coruña, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Piñeiro
authors.affiliation: Department of Cell and Molecular Biology, Faculty of Sciences, University of A Coruña, A Coruña, Spain.|Neurover Group, Centro de Investigaciones Científicas Avanzadas (CICA), University of A Coruña, A Coruña, Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Folgueira
authors.affiliation: Department of Cell Biology and Ecology, Faculty of Biology, University of Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Anadón
mesh_terms: D000344:Afferent Pathways / Q000166:cytology* / Q000502:physiology; D000818:Animals; D001921:Brain / Q000166:cytology* / Q000502:physiology; D002232:Carbocyanines; D013194:Staining and Labeling; D055697:Taste Perception / Q000502:physiology; D014781:Viscera / Q000294:innervation; D015027:Zebrafish / Q000033:anatomy & histology* / Q000502:physiology
chemical_list: D002232:Carbocyanines; C072024:carbocyanine dye DiIC12(3)
keywords: Danio rerio; RRID:SCR_003070; RRID:SCR_014235; cyprinids; hypothalamus; neural connections; taste; telencephalon