STUDY ON THE MECHANISM OF MUTUAL RECOGNITION BETWEEN NEURONS OF THE PERIPHERAL NERVOUS SYSTEM.

将WGA-HRP大量注入颈上神经节(SCG)，引起SCG内节后神经元的强烈标记，随后WGA-HRP顺着轴突被携带到神经末梢并最终释放。它被其他神经元的轴突重新摄取，并在它们的体细胞内运输和积累。这一机制可称为WGA-HRP的前-后-跨神经元标记。利用这一机制，我们研究了头颈部交感、副交感和感觉神经元之间的联系。WGA-HRP注入右侧SCG后3~4d，左侧SCG和星状神经节内可见大量重标记神经元。而在副交感植物神经节如睫状神经节、翼腭神经节和耳神经节，以及在感觉神经节如三叉神经节和C2-C8脊神经节，仅观察到少数弱标记神经元。这些结果表明，交感节后神经元在中线和纵切段之间形成了很强的神经元联系，但没有建立起副交感神经元和感觉神经元之间的具体联系。WGA-HRP跨神经元交换的事实表明，交感神经元可能交换一种特定的特征物质，使相邻神经元识别它们的存在。交感神经节后神经元向同类型神经元发出的信号比副交感神经元和声波神经元的信号更强。信号物质的性质及其对神经元功能的影响有待进一步研究。

A large amount of WGA-HRP injection into the superior cervical ganglion (SCG) induced a strong labeling of the postganglionic neurons in the SCG.Thereafter WGA-HRP was anterogradely carried along their axons to the nerve terminals and finally released. It was taken up agoin by the axon of the other neurons and transported and accumulated within their somata. This mechanism can be called as an antero-retro-transneuronal labeling of WGA-HRP.By using this mechanism the connection between the sympathetic, parasympathetic and sensory neurons in the craniocervical region was examined. Three to four days after the WGA-HRP injection into the right SCG,many heavily labeled neurons were observed in the SCG and the stellate ganglia in the left side. However, in the parasympathetic autonomic ganglia, such as the ciliary, pterygopalatine and otic ganglia, as well as in the sensory ganglia, such as the trigeminal and C2-C8 spinal ganalia, only a few slightly labeled neurons were observed. These results suggested that the sympathetic postganglionic neurons form a strong neuronal connection each other over the midline and over the longitudinal segmentation, but did not make so concrete relationship between the parasympathetic and sensory neurons. The fact of transneuronal exchange of WGA-HRP suggests that the sympathetic neurons may exchange a spesific characteristic substance which makes the neighboring neuurons to recognize their existance. The sympathetic postganglionic neurons give a signal to the same sorts of neurons stronger than the parasympathetic and sonsory of neurons. Further investigation concerning the property of signal substance and its effect on the neuronal functions should be done in the future.