Research report Stem cells distribution, cellular proliferation and migration in the adult Austrolebias charrua brain Maximiliano Torres-Pérez a , Juan Carlos Rosillo a,e , Ines Berrosteguieta a , Silvia Olivera-Bravo b , Gabriela Casanova c , José Manuel García-Verdugo f , Anabel Sonia Fernández a,d,⇑ a Departamento NCIC, Neuroanatomía Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay b Neurobiología Celular y Molecular, Instituto de Investigaciones Biológicas ‘‘Clemente Estable” (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay c Unidad de Microscopia Electrónica, Facultad de Ciencias, Universidad de la República (UdelaR), Iguá 4225, 11400 Montevideo, Uruguay d Neuroanatomía Comparada, Unidad Asociada a la Facultad de Ciencias, Universidad de la República (UdelaR), Iguá 4225, 11400 Montevideo, Uruguay e Departamento de Histología y Embriología de la Facultad de Medicina UdelaR, Avda. General Flores 2125, 11800 Montevideo, Uruguay f Laboratorio de Neurobiología Comparada, Instituto Cavanilles, Universidad de Valencia, Paterna 46980, CIBERNED, Spain article info Article history: Received 8 March 2017 Received in revised form 27 July 2017 Accepted 3 August 2017 Available online 8 August 2017 Keywords: Stem cell Fish brain Cell proliferation Austrolebias abstract Our previous studies demonstrated that Austrolebias charrua annual fish is an excellent model to study adult brain cell proliferation and neurogenesis due to the presence of active and fast neurogenesis in sev- eral regions during its short lifespan. Our main goal was to identify and localize the cells that compose the neurogenic areas throughout the Austrolebias brain. To do this, we used two thymidine halogenated analogs to detect cell proliferation at different survival times: 5-chloro-2 0 -deoxyuridine (CldU) at 1 day and 5-iodo-2 0 -deoxyuridine (IdU) at 30 days. Three types of proliferating cells were identified: I – tran- sient amplifying or fast cycling cells that uptake CldU; II – stem cells or slow cycling cells, that were labeled with both CldU and IdU and did not migrate; and III – migrant cells that uptake IdU. Mapping and 3D-reconstruction of labeled nuclei showed that type I and type II cells were preferentially found close to ventricle walls. Type III cells appeared widespread and migrating in tangential and radial routes. Use of proliferation markers together with Vimentin or Nestin evidenced that type II cells are the putative stem cells that are located at the ventricular lumen. Double label cells with IdU+ and NeuN or HuC/D allowed us identify migrant neurons. Quantitation of labeled nuclei indicates that the proportion of puta- tive stem cells is around 10% in all regions of the brain. This percentage of stem cells suggests the exis- tence of a constant brain cell population in Austrolebias charrua that seems functional to the maintainance of adult neurogenesis. Ó 2017 Elsevier B.V. All rights reserved. 1. Introduction The study of proliferation in the adult brain in different verte- brate taxa, has shown the existence of important differences in relation to the proliferative and neurogenic capacities (Font et al., 2001; Nottebohm, 2002; Chapouton et al., 2007; Kaslin et al., 2008; Gould, 2007; Ming and Song, 2011; Maruska et al., 2012; Grandel and Brand, 2013). Proliferative capacity in the brain fulfill two essential objectives, first to generate new cells that support the structural growth and secondly, generate neurons that http://dx.doi.org/10.1016/j.brainres.2017.08.003 0006-8993/Ó 2017 Elsevier B.V. All rights reserved. Abbreviations: A, anterior thalamic nucleus; CC, crista cerebellaris; CCe, corpus cerebelli; Dc1, central zone of dorsal telencephalon; Dc2, central zone of dorsal telencephalon; Dd, dorsal zone of dorsal telencephalon; DIL, diffuse interior lobe of hypothalamus; DiV, diencephalic ventricle; Dm1-2-3-4, medial zone of dorsal telencephalon; Dp, posterior zone of dorsal zone of telencephalon; Dlv, ventro-lateral zone of dorsal telencephalon; Dld, dorso-lateral zone of dorsal telencephalon; gl, granular layer of cerebellum; ECL, external cellular layer; EG, eminentia granularis; GL, glomerular layer; H, hypothalamus; Hyp, hypophysis; ICL, internal cellular layer; IL, inferior lobe; OB, olfactory bulb; ON, optic nerve; OT, optic tectum; PGZ, periglomerular gray zone; PM, magnocellular preoptic nucleus; PoA, preoptic area; PPp, parvocellular portion of preoptic nucleus; RMS, rostral migratory stream; SC, suprachiasmatic nucleus; Tel-D, dorsal zone of telencephalon; Tel-V, ventral zone of telencephalon; TeV, tectal ventricle; TL, torus longitudinalis; TS, torus semicircularis; Va, valvula cerebelli; Vd, dorsal zone of ventral telencephalon; VL, ventricular lumen; VM, ventro-medial thalamic nucleus; Vs, supracommisural zone of ventral telencephalon; Vv, ventral zone of ventral telencephalon. ⇑ Corresponding author at: Instituto de Investigaciones Biológicas ‘‘Clemente Estable” (IIBCE), Avenida Italia 3318, Montevideo 11600, Uruguay. E-mail addresses: mtorres@iibce.edu.uy (M. Torres-Pérez), jrosillo@iibce.edu.uy (J.C. Rosillo), solivera@iibce.edu.uy (S. Olivera-Bravo), casanova@fcien.edu.uy (G. Casanova), j.manuel.garcia@uv.es (J.M. García-Verdugo), anabelsonia@gmail.com, afernandez@iibce.edu.uy (A.S. Fernández). Brain Research 1673 (2017) 11–22 Contents lists available at ScienceDirect Brain Research journal homepage: www.elsevier.com/locate/bres