Coughlin M D, Collins M B
Dev Biol. 1985 Aug;110(2):392-401. doi: 10.1016/0012-1606(85)90098-3.
Although ganglia from neonatal mouse sympathetic ganglia require nerve growth factor (NGF) for survival in culture, explanted sympathetic ganglia from early embryonic stages do not require added NGF for survival and growth. To determine whether the change in growth factor requirement is due to changes in the neurons themselves, to variations in neuronal populations, or to changes in nonneuronal cells, we examined the response to growth factors by dissociated sympathetic neurons at various stages of development. Results indicate that neurons from the 14-day gestational (E14) superior cervical ganglion (SCG) do not require NGF for initial survival and neurite extension, but do require the conditioned medium neurite extension factor, CMF. By 2 to 3 days thereafter, whether in vivo or in culture, most neurons have developed a requirement for NGF for survival in culture. During the same period, there is a concomitant increase in responsiveness to NGF alone as a trophic agent. Changes in response to NGF are not due to changes in NGF content of ganglia, to interactions in culture with nonneuronal cells, or to age-related differences in NGF requirements for maximum survival. The changes in growth factor requirements may be related to mechanisms regulating specificity of nerve-target connections.
虽然新生小鼠交感神经节的神经节在培养中需要神经生长因子（NGF）来维持存活，但早期胚胎阶段移出的交感神经节在存活和生长时不需要添加NGF。为了确定生长因子需求的变化是由于神经元自身的变化、神经元群体的差异还是非神经元细胞的变化，我们检测了不同发育阶段解离的交感神经元对生长因子的反应。结果表明，来自妊娠14天（E14）颈上神经节（SCG）的神经元在初始存活和神经突延伸时不需要NGF，但确实需要条件培养基神经突延伸因子CMF。此后2至3天，无论在体内还是在培养中，大多数神经元在培养中存活都对NGF产生了需求。在同一时期，作为一种营养因子，对单独NGF的反应性也随之增加。对NGF反应的变化不是由于神经节中NGF含量的变化、培养中与非神经元细胞的相互作用，也不是由于与最大存活所需NGF的年龄相关差异。生长因子需求的变化可能与调节神经-靶标连接特异性的机制有关。
