兔外膝体的生后发育

THE POSTNATAL DEVELOPMENT OF THE LATERAL GENICULATE BODY OF THE RABBIT

外膝体是动物视觉系统的中间站,以前学者对其形态结构曾作过大量的工作,但关于它发育过程的研究却很少。Rose(1942)[1]曾作过兔间脑的个体发育,Cooper(1945)[2]曾有人类外膝体发育的研究,Левын(1957)[3]有爬行类和哺乳类外膝体的胚胎发育,Преображенская(1961)[4]有视分析器结构的发育,和Сухецкая(1961)的个体发育研究中的人外膝体的结构和联系等少数几篇报导而已。

The postnatal morphological development of the lateral geniculate body was studiedon the basis of Nissl and Golgi-Cox preparations.Fifty-five rabbits ranging in agefrom newborn to adult were used in the present investigation.The following resultswere obtained.In the course of postnatal development of the lateral geniculate body in rabbitstwo successive stages can be distinguished.In the first stage which last for about 15 daysafter birth,the volume of pars dorsalis and pars ventralis of this nucleus increasesrapidly and the cell concentration of the nucleus decreases correspondingly.Differentia-tion of the neurons also attained its climax at the end of this stage.In the secondstage,i.e.from the 15th day on,the growth of nerve cells slows down abruptly,exceptthat the length of their dendrites continue to grow until the 30th day.From the results of this and of our previous investigations it is concluded that thedevelopment of the cortical and the subcortical structures of the visual system in therabbit all approach their matured conditions at about the same time.