• • 上一篇    下一篇

牦牛海马的形态特征及成体神经发生的初探

许文强,徐鑫佳,范力,邵虹,刘兵峰,邵宝平,王建林,赵善廷   

  1. 兰州大学生命科学学院
  • 出版日期:2012-05-24 发布日期:2012-05-20

Morphological characteristics and the first examination of adult neurogenesis of the hippocampus in yak

  • Online:2012-05-24 Published:2012-05-20

摘要: 采用传统H.E 染色和Golgi-Cox 染色方法观察成年牦牛海马结构的形态和细胞构筑,并通过DCX - DAB免疫组化染色和DCX/ NeuN、GFAP / NeuN 双重免疫荧光标记等技术观察齿状回颗粒下层中的新生神经元和放射状胶质细胞。结果表明,牦牛海马结构主要包括齿状回和海马本部,二者分层清晰。海马的主要细胞为颗粒细胞、苔藓细胞和锥体细胞。CA3 区的锥体细胞胞体较CA1 区的大,但其顶树突的平均长度较短。CA1 区的锥体细胞明显分为两层,而CA3 区的则为一层。DCX 阳性细胞的胞体主要集中在齿状回颗粒下层靠近门区处,沿颗粒层内侧单个或少数聚集分布。沿齿状回颗粒下层分布着一层GFAP 阳性的放射状胶质细胞样细胞,其胞质和单极性的细长突起均呈GFAP 阳性,而胞核为阴性。在整个海马结构中均有大量星形GFAP 阳性细胞散在分布,特别是海马分子层和门区内靠近颗粒层部分的密度较其它部位大。牦牛海马的形态结构与绵羊的相似,而与大鼠、小鼠、家猫、兔子等小型哺乳动物有一定差别。两种DCX 免疫组化实验结果表明在牦牛海马中存在着新生神经元。GFAP 免疫荧光标记表明,牦牛海马结构中分布有星形胶质细胞;特别是放射状胶质细胞。

关键词: 牦牛, 齿状回, 双皮质素, 成体神经发生

Abstract: The morphology and cell types of the hippocampus in adult yak were examined by the traditional staining of H. E and Golgi-Cox,and the neural stem cells and newborn neurons which located in Subgranular zone (SGZ)of the dentate gyrus were observed with Diaminobenzidine (DAB)immunoperoxidase staining and immunofluorescence double-labeling
for Doublecortin and Neuronal Nuclei (DCX/ NeuN),Glial fibrillary acid protein and Neuronal Nuclei (GFAP/ NeuN). Our data indicate that the yak’s hippcampus mainly contains dentate gyrus and hippocampus proper,and both of them stratify clearly. Granular cells,mossy cells and pyramidal cells are the three major cell types of the hippocampus formation. The soma of pyramidal cells in the CA3 region is much bigger than in the CA1 region,while the latter has an average length of apical dendrites longer than the former. The pyramidal cells contain distinctive sublayers in the CA1 regions,but form a close uniform layer in the CA3 region. The somas of most DCX-positive cells,which distribute individually or in clusters,mainly locate in the deepest part of the granule cell layer closing to the hilus. A layer of GFAP-expressing radial glia-like cells is observed in the subgranular zone of the dentate gyrus,and its cytoplasms and single polarity processes,but not nucleus,are GFAP-positive. A large number of star GFAP-positive cells is scattered throughout the hippocampus. Specially, the densities of GFAP-positive cells in the molecular layer and the boundary of the hilus closing to the granular layer are much higher than those in other zones. The morphological characteristics of the hippocampus in yak is similar to those observed in sheep,but differ from those reported in small mammals,such as rats,mice,cats,and rabbits. Finally,the DCX immunostaining indicates the presence of the newborn neurons in yak’s hippocampus. The immunofluorescence labeling for GFAP also indicates the astrocytes,especially radial glia,in the yak’s hippocamous.