人胎大脑额叶一氧化氮合酶阳性神经元发育的免疫组化研究

An immunohistochemical study on the deveploment of the nitire oxide synthase positive neurons in the lobus frontial of cerebrum of human fetus

目的:探讨人胎大脑额叶一氧化氮合酶(NOS)阳性神经元发育的规律。方法:用免疫组化法观察第3～6个月胎龄人胎大脑额叶NOS阳性神经元的表达。结果:第3～4个月龄时,中间层可见到NOS阳性神经元,胞体较小,呈圆形、椭圆形或梭形,核大,胞质极少,呈散在分布。神经元的一端或两端有短小的突起,有的神经元突起较长,在神经元之间有细小的膨体神经纤维分布,其他各层未见到NOS阳性神经元。第5～6个月龄时,中间层NOS阳性神经元形态各异,有的胞体较大,在胞质和伸长的突起内出现明显的NOS阳性颗粒,有的神经突起形成分支,并延伸到小血管管壁上,膨体纤维分布密度增加。结论:大脑额叶NOS阳性神经元的生长发育对其他多种神经元和神经胶质细胞的分化、增殖、迁移等具有重要作用,而且对大脑的血管和NOS阳性神经元自身的生长发育亦具有重要作用。

Objective To explore the development regularity of nitire oxide synthase（NOS） positive neurons in the lobus frontalis of the cerebrum of human fetus. Methods The expression of the NOS positive neurons in the lobus frontalis of the cerebrum of human fetus from the third to sixth month of gestation was observed by using the immunohistochemical methods. Results At the third to fourth mouth of gestation, the NOS positive neurons were seen in the central layer. Bodies of the neurons were small, being in the shape of a round, a oval or a fusiform. The nucleus of the cell was bigger, while there was only a little cytoplasm, the distribution of the cell was scattered. An end or both ends of the neurons had a short and small processes, of which some was lengthened. There were the fine beaded nerve fibers between the neurons. The nerve tissue of other layers did not detect NOS positive neurons. At the fifth to sixth month, the shape of NOS positive neurons were different in the central layer. The bodies of some neuron were bigger, the cytoplasm and lengthened processes contained obviously NOS positive granules, some of the processes formed tree branches being extended to the wall of small blood vessels. The density of the distribution of the beaded nerve fibers were increased. Conclusion It is suggested that the growth and development of NOS positive neurons in the lobus frontalis of the cerebrum plays an important role in the differentiation, multiplication, migration, etc of other kind of neurons and neuroglioeytes and in the growth and development of the cerebral blood vessels and NOS positive neurons themselves.