Straznicky C, Rush R A
Anat Embryol (Berl). 1985;171(3):357-63. doi: 10.1007/BF00347024.
In chick embryos, on the 3rd day of incubation, the developing right wing bud was removed. One group of the operated embryos was treated with a daily dose of 20 micrograms purified nerve growth factor (NGF) from the 5th day of incubation and sacrificed on the 12th day. The other group was sacrificed on the 12th day of incubation and served as control. NGF was also administered to intact, unoperated embryos for comparison. The size of the dorsal root ganglia in segments 13-16 innervating the wings, were estimated and the number of surviving dorsal root ganglion cells counted both on the right (operated) and left (intact) sides. Although NGF brought about an increase in the size of the ganglia and an increase in the number of dorsal root ganglion cells bilaterally, it was not able to prevent excessive cell death of dorsal root ganglion cells on the operated side. The number of surviving neurons in the dorsal root ganglia on the operated side in embryos with or without NGF administration was only about 30-50% of the number of the intact side. These results show that cell death induced by target removal cannot be offset by NGF administration. It is concluded that NGF may act as a growth promoting agent for developing sensory neurons but other peripheral trophic factor/s are also needed for the maintenance and survival of dorsal root ganglion cells.
在鸡胚孵化的第3天，切除发育中的右翼芽。一组手术胚胎从孵化第5天开始每天给予20微克纯化的神经生长因子（NGF），并在第12天处死。另一组在孵化第12天处死作为对照。也对完整未手术的胚胎给予NGF以作比较。估计支配翅膀的第13 - 16节段背根神经节的大小，并对右侧（手术侧）和左侧（完整侧）存活的背根神经节细胞数量进行计数。尽管NGF使双侧神经节大小增加且背根神经节细胞数量增多，但它无法阻止手术侧背根神经节细胞的过度死亡。无论是否给予NGF，手术侧胚胎背根神经节中存活神经元的数量仅为完整侧的约30 - 50%。这些结果表明，去除靶组织诱导的细胞死亡不能通过给予NGF来抵消。结论是，NGF可能作为发育中感觉神经元的生长促进剂，但背根神经节细胞的维持和存活还需要其他外周营养因子。
