Ard M D, Morest D K, Hauger S H
Neuroscience. 1985 Sep;16(1):151-70. doi: 10.1016/0306-4522(85)90053-3.
The effect of the availability of synaptic targets on neuronal survival was tested by explanting the cochleovestibular ganglion from embryonic day 3-1/2 chick embryos and maintaining it in the presence or absence of appropriate synaptic target tissues for 14 days in culture. The targets were the inner ear, peripherally, and the myelencephalon, centrally. Light and electron microscopic observations showed that the ganglion cells in the explants with targets present had generally achieved a degree of differentiation comparable to that of their counterparts in embryonic day 14 embryos. The variety of cell types seen in the normal embryonic day 14 ganglia was also evident in vitro. In ganglia explanted without peripheral or central targets, few neurons survived. Ganglia explanted with either peripheral or central target intact showed considerably better survival than those explanted without any target. Ganglia explanted with only the peripheral target (the inner ear) survived equally as well as those with both central and peripheral targets. Ganglia cultured with the central target (myelencephalon) did not survive as well as those with peripheral targets. The effect of the peripheral target on the ganglion was less clear-cut when ganglia were first dissected from their targets and then recombined in culture. However, the results of such experiments in which nerve fascicles were traced in serial sections from ganglia to target areas, suggest that the actual innervation of target cells, as well as proximity of ganglia to target tissues, could influence neuronal survival. Establishment of innervation appeared to be selective, in that the closest available target area was not always the one contacted by the ganglionic fibers. The present findings are consistent with a role of neuron-target cell interactions in supporting neuronal survival in the cochleovestibular ganglion of the chick embryo. Both the central and the peripheral targets are implicated in trophic interactions with the sensory neurons.
通过移植来自胚胎第3.5天鸡胚的耳蜗前庭神经节，并将其在有或没有合适突触靶组织的情况下培养14天，来测试突触靶标的可用性对神经元存活的影响。外周的靶标是内耳，中枢的靶标是延髓。光镜和电镜观察表明，有靶标的外植体中的神经节细胞通常已达到与胚胎第14天胚胎中的对应细胞相当的分化程度。正常胚胎第14天神经节中可见的各种细胞类型在体外也很明显。在没有外周或中枢靶标的外植神经节中，很少有神经元存活。有完整外周或中枢靶标的外植神经节的存活率明显高于没有任何靶标的外植神经节。仅移植外周靶标（内耳）的神经节与同时移植中枢和外周靶标的神经节存活情况相同。用中枢靶标（延髓）培养的神经节不如用外周靶标培养的神经节存活得好。当神经节首先从其靶标中分离出来然后在培养中重新组合时，外周靶标对神经节的影响不太明确。然而，在这些实验中，从神经节到靶标区域的连续切片中追踪神经束的结果表明，靶细胞的实际神经支配以及神经节与靶组织的接近程度可能影响神经元的存活。神经支配的建立似乎是有选择性的，因为最接近的可用靶标区域并不总是神经节纤维接触的区域。目前的研究结果与神经元-靶细胞相互作用在支持鸡胚耳蜗前庭神经节神经元存活中的作用一致。中枢和外周靶标都参与了与感觉神经元的营养相互作用。
