Collins F, Lee M R
J Neurosci. 1982 Apr;2(4):424-30. doi: 10.1523/JNEUROSCI.02-04-00424.1982.
From stages 35 to 40 in the chicken embryo, ciliary ganglion neurons undergo a developmental change which is detected in our assay system as a marked decline in the ability to extend neurites when placed in culture. This developmental loss is observed when the neurons are placed in culture as single, dissociated cells or as undissociated ganglion explants. The loss of the ability to extend neurites in culture is not a transitory phenomenon, for no recovery of this ability is observed during the rest of embryonic development or posthatching. There is a close temporal correlation between the embryonic period during which the ability of ciliary ganglion neurons to extend neurites declines and the period (stages 35 to 40) when these neurons form functional peripheral synapses in the embryo. The ability to extend neurites rapidly is not recovered during normal development as long as the ganglion and its connections within the organism remain intact. However, if the ciliary ganglia are removed from a stage 40 embryo and cultured for 3 to 4 days before being dissociated, the neurons have largely recovered their ability to initiate neurite outgrowth rapidly. This recovery after removal from the embryo is also presumably responsible for the eventual dense outgrowth of neurites from stage 40 ganglion explants after a 3- to 4-day delay in culture. Our results, in conjunction with similar results from other systems, suggest a cause and effect relationship between the establishment or disruption of peripheral connections and the loss or recovery, respectively, of the ability to extend neurites rapidly.
在鸡胚发育的第35至40阶段，睫状神经节神经元经历了一种发育变化，在我们的检测系统中，这种变化表现为当置于培养环境中时，其延伸神经突的能力显著下降。当将这些神经元作为单个解离细胞或未解离的神经节外植体置于培养环境中时，均可观察到这种发育性丧失。培养环境中延伸神经突能力的丧失并非短暂现象，因为在胚胎发育的其余阶段或孵化后均未观察到这种能力的恢复。睫状神经节神经元延伸神经突的能力下降的胚胎期与这些神经元在胚胎中形成功能性外周突触的时期（第35至40阶段）之间存在密切的时间相关性。只要神经节及其在机体内的连接保持完整，在正常发育过程中快速延伸神经突的能力就不会恢复。然而，如果从第40阶段的胚胎中取出睫状神经节并在解离前培养3至4天，神经元在很大程度上恢复了它们快速启动神经突生长的能力。从胚胎中取出后的这种恢复可能也是造成第40阶段神经节外植体在培养3至4天延迟后最终神经突密集生长的原因。我们的结果，结合其他系统的类似结果，表明外周连接的建立或破坏分别与快速延伸神经突能力的丧失或恢复之间存在因果关系。
