Luis de la Iglesia J A, Lopez-Garcia C
Neurobiología, Biología Celular, Facultad de Ciencias Biológicas, Universidad de Valencia, Spain.
J Comp Neurol. 1997 Sep 8;385(4):528-64. doi: 10.1002/(sici)1096-9861(19970908)385:4<528::aid-cne4>3.0.co;2-5.
The medial cortex of lizards is a simple three-layered brain region displaying many characteristics that parallel the hippocampal fascia dentata of mammals. Its principal neurons form a morphologically diverse population, partly as a result of the prominent continuous growth of this nervous center. By using the classic Golgi impregnation method, we describe here the morphology of the principal neurons populating the medial cortex of Podarcis hispanica. These were projection neurons giving off descending axons. These axons displayed deep collateral branches provided with prominent axonal boutons, while the main axonal branch reached adjacent cortical areas and the bilateral septum. According to three main classification criteria, dendritic tree pattern, dendritic spine covering, and soma size, we have distinguished eight different types of projection neurons. Five of them, "heavily spiny granular" (monotufted, medium-sized), "heavily spiny bitufted" (large), "spiny bitufted" (medium-sized), "sparsely spiny bitufted" (small), and "superficial multipolar" (small), were found in the cell layer, whereas the three others lay outside this layer and were regarded as ectopic types ("outer plexiform ectopic bitufted," "inner plexiform ectopic bitufted", and "inner plexiform monotufted"). Additional secondary criteria, soma position and shape, allowed us to further classify bitufted neurons into three distinct subtypes each: "superficial-round," "intermediate-fusiform," and "deep-pyramidal." Moreover, a variety of small impregnated cells were observed; they probably represented newly generated immature neurons that had not yet completed their development. These cell types were compared with those reported previously in Golgi, immunocytochemical, and electron-microscopy studies, both in the reptilian medial cortex and in the mammalian dentate area. Presumably age-related changes and synaptic relationships of these projection cells in the medial cortex circuitry were analyzed.
蜥蜴的内侧皮质是一个简单的三层脑区，具有许多与哺乳动物海马齿状回相似的特征。其主要神经元构成了一个形态多样的群体，部分原因是这个神经中枢持续显著生长。通过使用经典的高尔基浸染法，我们在此描述了西班牙壁蜥内侧皮质中主要神经元的形态。这些是发出下行轴突的投射神经元。这些轴突具有深侧支，其上有明显的轴突终扣，而主要轴突分支延伸至相邻的皮质区域和双侧隔膜。根据树突树模式、树突棘覆盖情况和胞体大小这三个主要分类标准，我们区分出了八种不同类型的投射神经元。其中五种，“多棘颗粒型”（单簇状，中等大小）、“多棘双簇状”（大）、“棘状双簇状”（中等大小）、“少棘双簇状”（小）和“浅层多极型”（小），位于细胞层，而另外三种位于该层之外，被视为异位类型（“外丛状异位双簇状”、“内丛状异位双簇状”和“内丛状单簇状”）。额外的次要标准，胞体位置和形状，使我们能够将双簇状神经元进一步细分为三种不同的亚型：“浅层圆形”、“中间梭形”和“深层锥形”。此外，还观察到了多种小的浸染细胞；它们可能代表尚未完成发育的新生成的未成熟神经元。我们将这些细胞类型与先前在爬行动物内侧皮质和哺乳动物齿状区的高尔基染色、免疫细胞化学和电子显微镜研究中报道的细胞类型进行了比较。推测分析了内侧皮质回路中这些投射细胞可能与年龄相关的变化及突触关系。
