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本文对大鼠出生前、后的大脑皮质神经元发育进行了光镜和电镜的研究。妊娠11天胚胎(E_(11))端脑泡由充满游离的单个或多聚核蛋白体的神经上皮细胞组成。其呈放射状紧密排列,近神经管腔处有分裂细胞存在。E_(15)时,脑泡壁细胞排列出现四层结构。在E_1,尤其明显,从内向外为室管膜层、套层、皮质板和边缘层。除室管膜层外,均存有分化不一的迁移细胞。核染色质由分布不均的细颗粒组成,核质密度低,含1—2个核仁,胞质含大量多聚核蛋白体。可见粗面内质网、线粒体、少数光面小泡。出现轴突而树突正在形成。出生后5天(P_5),皮质内未成熟神经元胞质内粗面内质网池增多,偶见3—4行排列。细胞开始散开,突触正在形成。从P_(12)到P_(19),神经元逐渐成熟。核染色质很细,核质电子密度低,大多含一个核仁。细胞质内见成行排列的粗面内质网,多个发达的高尔基复合体,丰富的多聚核蛋白体及微管、神经微丝、膜下囊等。并见多个轴体突触。细胞之间被神经毡充满。P_(34)到P_(51),神经元发育更完善。本文提示在神经元发育的不同阶段,细胞的不同组合排列和细胞核、核蛋白体、粗面内质网、高尔基复合体和神经突起等的超微结构变化,在作为细胞分化、成熟的标志中,均有特殊意义。此外,对形态结构的变化与功能关系进行了讨论。
In this paper, the development of rat cerebral cortex neurons before and after the birth were studied by light and electron microscopy. The 11-day-old embryo (E_ (11)) endoblasts consisted of neuroepithelial cells filled with free single or multi-nucleoprotein. The radial arrangement closely, near the neural tube at the presence of dividing cells. E_ (15), the arrangement of four cells in the parietal cells. It is especially evident at E_1, from the inside out to the ependymal layer, sheathing, cortical plate and edge layer. In addition to ependymal layer, there are differentiated migration of cells. Nuclear chromatin consists of uneven distribution of fine particles, nuclear density is low, containing 1-2 nucleoli, the cytoplasm contains a large number of polyribosomes. Visible rough endoplasmic reticulum, mitochondria, a few smooth vesicles. Axons appear and dendrites are forming. Five days after birth (P_5), the immature neurons within the cortex increased rough endoplasmic reticulum cytoplasm, occasionally arranged in rows of 3-4. Cells begin to spread and synapses are forming. From P_ (12) to P_ (19), neurons gradually matured. Nuclear chromatin is very fine, nuclear electron density is low, mostly contains a nucleolus. See the cytoplasm arranged in rows of rough endoplasmic reticulum, a number of developed Golgi complex, rich in polyribosomes and microtubules, neurofilament, subcapsular and so on. And see a number of axons synapses. Between the cells are filled with nerve felts. P_ (34) to P_ (51), neuronal development more perfect. This article suggests that in different stages of neuronal development, different combinations of cells and ultrastructural changes such as nucleus, nucleoprotein, rough endoplasmic reticulum, Golgi complex and neurite are the hallmarks of cell differentiation and maturation , Have special meaning. In addition, the morphological changes and functional relationships are discussed.