Zhou X, Hossain W A, Rutledge A, Baier C, Morest D K
Department of Anatomy, University of Connecticut Health Center, Farmington 06030, USA.
Hear Res. 1996 Apr;93(1-2):147-66. doi: 10.1016/0378-5955(95)00222-7.
The effects of basic fibroblast growth factor (FGF-2) on presumptive auditory and vestibular neurons from the medulla were studied in primary cell cultures. The part of the rhombic lip that forms nucleus magnocellularis (homologue of the mammalian anteroventral cochlear nucleus) was explanted from white leghorn chicken embryos at Hamburger-Hamilton stage 28 (E5.5), the time when precursors of the magnocellularis bushy cells migrate and begin to differentiate in situ. In vitro the neuroblasts migrated onto 2-D substrates of purified collagen, differentiated, and expressed neuronal markers. One-half of the cultures were supplemented with human recombinant FGF-2 (10 ng/ml daily) for 5-7 days; the others, with fetal bovine serum. FGF-2 more than doubled the length of neurite outgrowth during the first 3 day treatment compared to serum, but the number of migrating neuroblasts was unaffected. Although neurites attained greater lengths in FGF-2, they usually degenerated after 4-5 days; in serum their growth continued for several weeks. Differentiation of neuronal structure, including axons and dendrites, began within 1-2 days in bFGF but required at least 5-7 days in serum. Histochemical observations in vitro and in situ with antibodies to FGF receptor demonstrated immunopositive patches on acoustico-vestibular neuroblasts at stage 28, when they are migrating and first forming their axons. The findings suggest that FGF-2 stimulates neurite outgrowth in the cochlear and vestibular nuclei. FGF-2 may accelerate cell death by overstimulating neuroblasts, but other factors are needed to sustain their further development.
在原代细胞培养中研究了碱性成纤维细胞生长因子（FGF-2）对延髓中假定的听觉和前庭神经元的影响。在汉伯格-汉密尔顿28期（E5.5）从白来航鸡胚胎中取出形成大细胞性核（哺乳动物前腹侧耳蜗核的同源物）的菱形唇部分，此时大细胞性浓密细胞的前体细胞正在原位迁移并开始分化。在体外，神经母细胞迁移到纯化胶原蛋白的二维基质上，分化并表达神经元标记物。一半的培养物补充人重组FGF-2（每天10 ng/ml），持续5 - 7天；另一半补充胎牛血清。与血清相比，在最初3天的处理中，FGF-2使神经突生长长度增加了一倍多，但迁移的神经母细胞数量未受影响。虽然在FGF-2中神经突达到了更长的长度，但它们通常在4 - 5天后退化；在血清中它们的生长持续数周。包括轴突和树突在内的神经元结构的分化在bFGF中1 - 2天内开始，但在血清中至少需要5 - 7天。用FGF受体抗体进行的体外和原位组织化学观察表明，在28期的听-前庭神经母细胞上有免疫阳性斑块，此时它们正在迁移并首次形成轴突。研究结果表明，FGF-2刺激耳蜗核和前庭核中的神经突生长。FGF-2可能通过过度刺激神经母细胞加速细胞死亡，但需要其他因素来维持它们的进一步发育。
