Campenot R B
Proc Natl Acad Sci U S A. 1977 Oct;74(10):4516-9. doi: 10.1073/pnas.74.10.4516.
A three-chamber culture system was devised in which neurites growing from small clusters of somas of sympathetic neurons penetrated a virtually fluid-impermeable barrier; thus the local fluid environment of the distal portions of the neurites could be controlled independently of the local fluid environment of the somas and proximal portions of the neurites. Neurites regularly penetrated the barriers if a high concentration of nerve growth factor was present on both sides, but never penetrated into chambers to which no nerve growth factor had been added. After neurites crossed the barrier, local removal of nerve growth factor from the distal portions of the neurites caused the growth of these portions to stop, and they eventually appeared to degenerate even though nerve growth factor was continuously present in the chamber that contained their somas and proximal portions. In contrast, local nerve growth factor was not required at the somas and proximal portions of the neurites; many neurons survived its withdrawal provided their somas were associated with neurite bundles that crossed into a chamber containing nerve growth factor. These results show that the growth, and probably the survival, of neurites depends upon nerve growth factor in their local environment, regardless of the nerve growth factor concentrations to which other portions of the neuron are exposed. This is entirely consistent with the notion that nerve growth factor released by sympathetic target tissues promotes the establishment and maintenance of appropriate neuron-target connections during development.
设计了一种三室培养系统，在该系统中，从交感神经元小细胞团生长出的神经突穿透了几乎不透液的屏障；因此，神经突远端部分的局部液体环境可以独立于细胞体以及神经突近端部分的局部液体环境进行控制。如果两侧都存在高浓度的神经生长因子，神经突会定期穿透屏障，但从不穿透到未添加神经生长因子的腔室中。神经突穿过屏障后，从神经突远端部分局部去除神经生长因子会导致这些部分的生长停止，即使含有细胞体和近端部分的腔室中持续存在神经生长因子，它们最终似乎也会退化。相比之下，神经突的细胞体和近端部分不需要局部神经生长因子；如果它们的细胞体与穿过进入含有神经生长因子的腔室的神经突束相关联，许多神经元在去除神经生长因子后仍能存活。这些结果表明，神经突的生长以及可能的存活取决于其局部环境中的神经生长因子，而与神经元其他部分所接触的神经生长因子浓度无关。这与交感靶组织释放的神经生长因子在发育过程中促进建立和维持适当的神经元 - 靶连接的观点完全一致。
