Quintana-Urzainqui Idoia, Sueiro Catalina, Carrera Ivan, Ferreiro-Galve Susana, Santos-Durán Gabriel, Pose-Méndez Sol, Mazan Sylvie, Candal Eva, Rodríguez-Moldes Isabel
Department of Cell Biology and Ecology, CIBUS, University of Santiago de Compostela, Spain.
Brain Behav Evol. 2012;80(2):127-41. doi: 10.1159/000339871. Epub 2012 Sep 13.
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.
先前在研究成年脑不同亚区的组织结构后，已确定了板鳃亚类脑的基本解剖结构。然而，尽管对不同种类的鲨鱼和鳐鱼进行了相对丰富的免疫组织化学和神经通路学研究，但一些脑亚区的组织结构仍不清楚。本研究聚焦于一些脑区，在这些脑区中，基于成体解剖数据确定的亚区仍存在争议，比如大脑皮质下区域，主要是纹状体亚区。利用小斑猫鲨（Scyliorhinus canicula）作为发育研究模型的巨大潜力，我们通过分析γ-氨基丁酸（GABA）、儿茶酚胺和神经肽（如P物质）免疫标记物的分布，对整个发育过程和胚后阶段的大脑皮质下区域进行了特征描述。此外，我们分析了参与端脑区域化的调控基因（如Dlx2、Nkx2.1和Shh）的表达模式，并在整个发育过程中追踪它们的衍生物与这些神经化学标记物分布的关系。为了进一步进行特征描述，我们还应用神经束追踪技术分析了大脑皮质下区域的神经支配模式。我们的观察结果可能有助于揭示板鳃亚类中各区域和核团的假定等效性，并支持与其他脊椎动物的同源性。
