Narayanan C H, Narayanan Y
J Embryol Exp Morphol. 1978 Apr;44:53-70.
Following transplantation of an additional optic primordium into the orbital mesenchyme of chick embryos of approximately 2 days of incubation age, the changes in cell number in the ciliary ganglion, accessory oculomotor and trochlear nuclei were studied at various stages of development. Cell counts were made at 1-day intervals from days 9 through 15 for ciliary ganglion, and from days 13 through 15 for the accessory oculomotor and trochlear nuclei. Cell counts for the ciliary ganglion on days 9 and 11 were similar on the operated and control sides which suggests that grafting of an additional optic primordium, and thus enlarging the periphery, is not involved in the control of proliferation. Comparison of the number of cells for the ciliary ganglia and the accessory oculomotor nuclei at days 13 and 15 showed an increase on the affected side ranging from 8 to 27%, and 9 to 33% respectively. We interpret this increase on the experimental side as a reduction in the number of degenerating cells that occur in normal development, as a result of an enlargement of the peripheral field of innervation. Three cases showed an increase in the number of cells in the trochlear nucleus ranging from 9 to 29%. This increase was attributed to an increase in the size of the superior oblique muscle of the operated side as determined by volumetric measurements. On the basis of the evidence we conclude that an enlarged periphery acts by regulating the level of naturally occurring cell death by reducing the amount of cell loss, leading to a corresponding increase in final cell number.
在将额外的视原基移植到孵化约2天的鸡胚眼眶间充质中后，研究了睫状神经节、动眼神经副核和滑车神经核在不同发育阶段的细胞数量变化。从第9天到第15天，每隔1天对睫状神经节进行细胞计数，从第13天到第15天对动眼神经副核和滑车神经核进行细胞计数。第9天和第11天，手术侧和对照侧睫状神经节的细胞计数相似，这表明移植额外的视原基从而扩大外周区域，并不参与增殖的控制。比较第13天和第15天睫状神经节和动眼神经副核的细胞数量，发现受影响侧分别增加了8%至27%和9%至33%。我们将实验侧的这种增加解释为由于神经支配外周区域扩大，正常发育过程中发生的退化细胞数量减少。3例滑车神经核细胞数量增加了9%至29%。这种增加归因于通过体积测量确定的手术侧上斜肌大小的增加。根据这些证据，我们得出结论，扩大的外周区域通过减少细胞损失来调节自然发生的细胞死亡水平，从而导致最终细胞数量相应增加。
