CNRS, UMR6026, Interactions Cellulaires et Moléculaires, and Centre de Ressources Biologiques Xénope, Université de Rennes1, Campus deBeaulieu, Bat. 13, Avenue du Général Leclerc, 35042 Rennes, France.
Brain Res. 2011 Aug 8;1405:31-48. doi: 10.1016/j.brainres.2011.06.032. Epub 2011 Jul 13.
In contrast to mammals, the brain of adult non-mammalian vertebrates exhibits a higher proliferative and/or neurogenic activity. To provide new models on this issue, we have examined origin, distribution and fate of proliferating cells in the entire brain of juvenile and adult Xenopus laevis. Using immunohistochemistry for the Proliferation Cell Nuclear Antigen (PCNA), and/or the thymidine analog, 5-Bromo-2' deoxyUridine (BrdU), the labeled cells are located in ventricular zones of the olfactory bulbs, cerebral hemispheres, preoptic region, ventral hypothalamus and cerebellum. Qualitatively, the highest level of proliferative cells was found in the telencephalic ventricles. By using in situ hybridization/immunocytochemistry double-labeling techniques, we demonstrate for the first time in post-metamorphic frog brain that the proliferative cells are localized in very close vivinity to the radial glial cells, progenitor cells that we have also identified in the ventricular layer using classical molecular markers (BLBP, Vimentin). In addition, after long post-BrdU administration survival times ranging between 14 and 28days, BrdU labeling combined with immunohistochemistry for markers of cell migration (DoubleCortin) or radial glial cells (BLBP), reveals that the proliferative cells are able to migrate from the ventricular zone into the brain parenchyma, most likely by migrating along the radial processes. Finally, at survival time of 28days and by using a combination of BrdU labeling and in situ hybridization for markers of differentiation states (Neuro-β-tubulin, Proteolipid Protein), we demonstrate that newborn cells can differentiate in large portion into either neurons or oligodendrocytes.
与哺乳动物相反，成年非哺乳动物的大脑表现出更高的增殖和/或神经发生活性。为了在这个问题上提供新的模型，我们检查了幼年和成年非洲爪蟾（Xenopus laevis）整个大脑中增殖细胞的起源、分布和命运。使用增殖细胞核抗原（PCNA）和/或胸苷类似物 5-溴-2'-脱氧尿苷（BrdU）的免疫组织化学，标记细胞位于嗅球、大脑半球、视前区、腹侧下丘脑和小脑的脑室区。从定性上看，增殖细胞的最高水平出现在端脑的脑室中。通过使用原位杂交/免疫细胞化学双重标记技术，我们首次在变态后青蛙大脑中证明，增殖细胞位于与放射状胶质细胞非常接近的位置，我们也使用经典的分子标记物（BLBP、Vimentin）在脑室层中鉴定出了祖细胞。此外，在 BrdU 给药后长达 14 到 28 天的存活时间内，BrdU 标记与细胞迁移标志物（DoubleCortin）或放射状胶质细胞标志物（BLBP）的免疫组织化学相结合，表明增殖细胞能够从脑室区迁移到脑实质中，最有可能通过沿着放射状突起迁移。最后，在 28 天的存活时间内，通过 BrdU 标记与分化状态标志物（Neuro-β-tubulin、Proteolipid Protein）的原位杂交相结合，我们证明新生细胞可以大部分分化为神经元或少突胶质细胞。
