妊娠20～24周人脑室管膜下区神经细胞组成

Composition of subventricular zone cells in the embryonic human brain at 20-24 midgestational weeks

目的:研究妊娠20～24周人胎脑室管膜下区(SVZ)神经细胞分化。方法:收集胎龄为20～24周的正常胚胎6例。快速解离SVZ并行即刻培养,4 h后应用特异免疫标记识别各类型神经细胞。结果:大约50%左右SVZ细胞为神经元[MAP2]细胞为(50.9±4.6)%,β-Ⅲ-tubulin细胞为(51.7±3.8)%],其中皮质神经元亚型calretinin中间神经元占(3.5±0.3)%;约1/3 SVZ细胞具有早形胶质细胞特性[vimentin]细胞为(32.7±1.5)%,GFAP细胞占(31.9+3.0)%];少突神经胶质前体细胞(PDGFR_α细胞)为(6.7±0.6)%,小胶质细胞(lectin细胞)占(1.1±0.1)%,神经干佯细胞(nestin细胞)为(14.6±0.9)%。大约有1/10 SVZ细胞正处于细胞分裂期[BrdU细胞占(11.0±0.02)%]。结论:妊娠20～24周,人类SVZ增殖活跃,包含有神经元、星形胶质细胞、少突神经胶质前体细胞、多潜能干细胞在内的各种细胞亚群。

Objective： To understand the differentiation of subventricular zone （SVZ） cells in the embryonic human brain at 20-24 midgestational weeks. Methods： Six normal embryoes with gestational ages of 20 24 weeks （g. w. ） were enrolled in this study. To determine the contribution of particular cell types to the entire population present in the SVZ, we did a quantitative study using acutely dissociated cell culture and immunostained within 4 hrs by different cell specific antibodies. Results： High viability （98.7%±0.4 %） was found in the dissociated cells, among which the approximately 500/00 of SVZ cells were neurons, and were labeled with MAP2 （50.9%±4.6） % or β- Ⅲ -tubulin （51.7%± 3.8%）. Subtypes of cortical neurons,such as calretinin interneurons represented 3.5%±0.3%. One third of SVZ cells were astroglia characterized with vimentin （32.7%±1.5%） or GFAP （31.90%±3.0%）. Other cell types, such as oligodendrocyte progenitor cells （PDGFR-a^＋ ） accounted for 6.7 % ± 0.6 %, microglia/macrophages （lectin-labeled） 1.1%±0. 1%, and stem-like cells （nestin^＋ ） 14.6%±0.9%. Approximately, one-tenth cells presented in SVZ were dividing, as shown by their BrdU incorporation （11.0 ± 0.2 %）. Conclusion： Various cell classes including neurons, astrocytes, oligodendroeyte progenitors, and muhipotential progenitors are proliferating in human SVZ at 20- 24 g. w.