Objective:To characterize the proliferation, migration and layer formation of neurons in chicken optic tectum by BrdU-labeling. Methods:The fertilized eggs were incubated in ovo for three days and one window was open upside. BrdU (1 mg/ml) was dropped from 4 to 18 incubation days, and five eggs were selected from each group when incubated at day 18. All samples were collected and fixed with 4% paraformaldehyde and sliced with vibratome. Newborn neurons were stained by thionin and immunohistochemistry to show BrdU labeled neurons. To comprehensively compare the differences in various stages of newborn neurons, six different visual areas were selected by bio-statistics software to analyze the number of proliferating cells, the total area, the average gray level, the average optical density and the average integral optical density in stratum griseum et fibrosum superficiale layer. Results:The chick embryo optic tectum structure was clearly divided into six layers. The stage of cell proliferation was at 4 d-8 d during embryonic development, the number of new cells was significantly higher than that in other stages, and newborn cells was significantly reduced after 12 d. Conclusion:During the chick embryo development, the development of optic tectum begins at 4 d and ends at 12 d, and the structure of 6 layers is formed after 12 d. The newborn neurons are decreased significantly after 12d and the the six-layer structure formation is arranged from the inside to outside.%目的:采用5-溴脱氧尿嘧啶核苷(BrdU)标记鸡胚发育过程巾视顶新生神经元,阐明鸡胚发育过程巾视顶盖神经元增殖、迁移规律.方法:采用鸡胚开窗带壳培养的方式,在培养过程巾,分别在胚胎发育的第E4天至E18.5 d滴加1 mg/ml浓度的BrdU各10μl,每组5个胚胎,滴加BrdU后密封开口,继续培养,当培养到胚胎发育的E18.5 d时,取材、甲醛固定、震荡切片,采用硫堇染色,观察视顶盖层的结构,免疫组织化学显示BrdU标记的新生细胞；显微拍照,分析不同时期表面灰质纤维层增殖细胞的数量、总面积、灰度平均值、平均光密度和平均积分光密度等参数,综合分析各阶段新生神经元的差异.结果:鸡胚视顶结构通过硫堇染色可以明显分成6层,在胚胎发育的E4 d～8 d是细胞大量增殖阶段,新生细胞数明显高于其他阶段；新生细胞在胚胎发育的E12 d后明显减少.结论:鸡胚发育过程中,视顶从胚胎发育的E4 d开始到E12 d时,6层结构已经基本形成,新生神经元E12 d后明显减少,其视顶盖6层结构的形成规律是从内向外.
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