出生前山羊大脑皮质的形成和发育

The Histogenesis and Development of Cerebral Cortex in Goat Fetus

对山羊胚胎大脑皮质形成及其神经元发育的形态学变化进行了研究,结果表明:(1)山羊胚胎不同类型大脑皮质的皮质板形成时间顺序为旧皮质、新皮质→海马皮质,与种系发生规律相反,提示神经系统内部结构的形成并非完全符合种系进化,而与动物个体组织结构自身的发展相关。不同类型大脑皮质皮质板的分化顺序为古皮质→旧皮质→新皮质,与种系发生的顺序相符。(2)山羊胚胎海马皮质锥体细胞的发育较早,按由深到浅的次序发育,而海马皮质中的非锥体细胞于第19周开始发育。梨状叶皮质锥体细胞发育的较早,最先出现在深层,颗粒层第18周出现。大脑新皮质各层神经元发育顺序依次为:内锥体层→外锥体层、多形层→内颗粒层→外颗粒层。各种类型皮质的神经元在出生前都未发育成熟。

The histogenesis and development of cerebral cortex were observed in goats fetus by using HE staining. The results showed：（1）The forming sequence of the cortex plate in different types cortex in goat fetus is from paleocortex and neocortex to archicortex,which is contray to the law of phylogeny. The differentiating sequence of the cortex plate in different types cortex in goat fetus is from archicortex to paleocortex and to neocortex,which is similar to the law of phylogeny. （2）The hippocampus cortex pyramidal cells develop very early and they develop from inner to the outer side,whereas those nonpyramidal cells develop from the nineteenth week in goat fetus. The pyriform lobe cortex pyramidal cells develop very early too and it appears in the inner side ,the granular cells begin to develop from the eighteenth week. The developing sequence of nerve cells is in order of medial pyramidal layer,lateral pyramidal layer and multiform lamina,medial granular layer and lateral granular layer. Varietis of neurons in cerebral cortex are all under matured before blrth,which need to go on develop after birth ,some may even have a longer developing time.