DeHamer M K, Guevara J L, Hannon K, Olwin B B, Calof A L
Department of Biological Sciences, University of Iowa, Iowa City 52242.
Neuron. 1994 Nov;13(5):1083-97. doi: 10.1016/0896-6273(94)90047-7.
Olfactory receptor neurons are produced continuously in mammalian olfactory epithelium in vivo, but in explant cultures neurogenesis ceases abruptly. We show that in vitro neurogenesis is prolonged by fibroblast growth factors (FGFs), which act in two ways. FGFs increase the likelihood that immediate neuronal precursors (INPs) divide twice, rather than once, before generating neurons; this action requires exposure of INPs to FGFs by early G1. FGFs also cause a distinct subpopulation of explants to generate large numbers of neurons continually for at least several days. The data suggest that FGFs delay differentiation of a committed neuronal transit amplifying cell (the INP) and support proliferation or survival of a rare cell, possibly a stem cell, that acts as a progenitor to INPs.
嗅觉受体神经元在哺乳动物体内的嗅觉上皮中持续产生，但在体外培养物中神经发生会突然停止。我们发现，成纤维细胞生长因子（FGFs）可延长体外神经发生，其作用方式有两种。FGFs增加了直接神经元前体细胞（INPs）在生成神经元之前分裂两次而非一次的可能性；这种作用需要INPs在G1早期暴露于FGFs。FGFs还会使一个独特的外植体亚群持续产生大量神经元，至少持续数天。数据表明，FGFs延迟了定向神经元过渡增殖细胞（INP）的分化，并支持一种罕见细胞（可能是干细胞）的增殖或存活，该细胞作为INP的祖细胞。
