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

向颈上神经节（SCG）注射大量WGA-HRP，可引起SCG中节后神经元的强烈标记。随后，WGA-HRP沿轴突顺行传递至神经末梢并最终释放。它再次被其他神经元的轴突吸收，并在它们的体细胞中运输和积累。该机制可称为WGA-HRP的前-后-跨神经元标记。利用这一机制，研究了颅颈区交感、副交感和感觉神经元之间的联系。向右侧SCG注射WGA-HRP后3 ~ 4天，在左侧SCG和星状神经节中可见大量重标记神经元。然而，在副交感神经自主神经节，如睫状神经节、翼腭神经节和耳神经节，以及感觉神经节，如三叉神经节和C2-C8脊髓神经节中，只观察到少数轻微标记的神经元。这些结果表明，交感神经节后神经元之间在中线和纵向分割上形成了很强的神经元连接，而副交感神经元和感觉神经元之间并没有如此具体的联系。WGA-HRP的跨神经元交换表明，交感神经元可能交换了一种特定的特征物质，使相邻神经元能够识别它们的存在。交感神经节后神经元向同类神经元发出的信号比副交感和感觉神经元强。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.