Torres-Pérez Maximiliano, Rosillo Juan Carlos, Berrosteguieta Ines, Olivera-Bravo Silvia, Casanova Gabriela, García-Verdugo José Manuel, Fernández Anabel Sonia
Departamento NCIC, Neuroanatomía Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay.
Departamento NCIC, Neuroanatomía Comparada, Instituto de Investigaciones Biológicas Clemente Estable (IIBCE), Avenida. Italia 3318, 11600 Montevideo, Uruguay; Departamento de Histología y Embriología de la Facultad de Medicina UdelaR, Avda. General Flores 2125, 11800 Montevideo, Uruguay.
Brain Res. 2017 Oct 15;1673:11-22. doi: 10.1016/j.brainres.2017.08.003. Epub 2017 Aug 8.
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 several 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'-deoxyuridine (CldU) at 1day and 5-iodo-2'-deoxyuridine (IdU) at 30days. Three types of proliferating cells were identified: I - transient 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 putative stem cells is around 10% in all regions of the brain. This percentage of stem cells suggests the existence of a constant brain cell population in Austrolebias charrua that seems functional to the maintainance of adult neurogenesis.
我们之前的研究表明，由于奥氏南美肺鱼这种一年生鱼类在其短暂的生命周期中，几个脑区存在活跃且快速的神经发生现象，所以它是研究成体脑细胞增殖和神经发生的优秀模型。我们的主要目标是识别并定位构成奥氏南美肺鱼整个大脑神经发生区域的细胞。为此，我们使用了两种卤代胸腺嘧啶核苷类似物，在不同存活时间检测细胞增殖情况：1天时使用5-氯-2'-脱氧尿苷（CldU），30天时使用5-碘-2'-脱氧尿苷（IdU）。我们识别出了三种增殖细胞：I型——摄取CldU的瞬时扩增或快速循环细胞；II型——同时被CldU和IdU标记且不迁移的干细胞或慢循环细胞；III型——摄取IdU的迁移细胞。对标记细胞核的映射和三维重建显示，I型和II型细胞优先出现在脑室壁附近。III型细胞广泛分布，并以切线和径向路径迁移。增殖标记物与波形蛋白或巢蛋白一起使用表明，II型细胞是位于脑室腔的假定干细胞。IdU+与NeuN或HuC/D的双标记细胞使我们能够识别迁移神经元。标记细胞核的定量分析表明，假定干细胞在大脑所有区域的比例约为10%。这种干细胞比例表明，奥氏南美肺鱼中存在一个恒定的脑细胞群体，这似乎对维持成体神经发生具有功能性作用。
