组织外植块对培养的鸡胚背根节神经突起生长的影响

为了解神经元的发育和周围组织的关系,本文分别用:(1) 10天鸡胚背根节与10天鸡胚心脏、皮肤、角膜、骨骼肌、肠、大脑、脊髓外植块联合培养;(2) 不同时期的鸡角膜与不同胚龄的鸡胚背根节联合培养;(3) 10天鸡胚背根节与雏鸡角膜内、外层联合培养。用于联合培养的背根节和组织外植块均按Maximow双盖片法种植在涂有鼠尾胶原的盖玻片上,两者相距1.5mm。外植块大小约0.5×1×1mm~3。培养48小时后取出固定,用改良的Bodian蛋白银法浸镀染色,在低倍镜下对神经突起进行半定量计数。 实验结果表明鸡胚心脏,皮肤和角膜外植块对背根节神经突起生长具较强的促进作用且对生长方向有明显诱导作用;骨骼肌、肠和大脑对神经突起生长也有不同程度促进作用,但脊髓却无明显作用。14、16、18天鸡胚角膜对8、10、12、14天鸡胚背根节神经突起生长有明显促进作用;12、14天鸡胚背根节在各时期角膜作用下神经突起生长都较丰富。含上皮层的雏鸡角膜外植块促进背根节神经突起生长的作用比含内皮层的角膜外植块要强。

Tissue Explants Affecting Neurite Outgrowth of Chick Embryonic Dorsal Root Ganglia in Culture

In order to know the relationship between the development of neurons and the peripheral tissues, three sets of experiments were conducted. (1) A number of tissue explants were cocultured with dorsal root ganglia (DRG) both dissected from 10 day old chick embryo. (2) Chick cornea of different developmental stages and embryonic DRG were cocultured. (3) Chick inner and outerlayer cornea from posthatching day 3 were cocultured with 10 day old chick embryonic DRG.The Maximow double-coverslip method was used for assay. Individual ganglia were explanted onto collagen-coated coverslips to face a piece of tissue placed at a distance of about 1.5mm. After 43 hours incubation, specimens were fixed and impregnated by modified Bodian's silver proteinate method. The extent of neurite outgrowth was counted (semi-quantitative)under the microscope.The results expressed that heart, skin and cornea explants not only possessed strong neurite promoting action on chick embryo DRG but also directed the orientation of neurites. Skeletal muscle, gut and cerebral tissue explants had in turn decreasingly stimulative influence on DRG, whereas spinal cord explants had no obvious neurite promoting activity. The cornea of 14, 16, 18 day chick embryo could elicit obvious neurite outgrowth from 8, 10, 12, 14 day chick embryo DRG, also 12 and 14 day chick embryo DRG showed obvious enhanced neurite outgrowth as a result of coculture with chick cornea explants of different developmental stages. The explants of posthatched chick cornea which contain epithelium had stronger neurite promoting action on chick embryo DRG than those contained endothelium.