以交感神经节为中心的中枢外反射弧的研究

用免疫组织化学ABC法和辣根过氧化物酶（HRP）法研究了感觉神经节和交感神经节中P物质（SP）样免疫反应物的分布及其两种神经节之间的相互联系。在所有背根节出现大量SP免疫阳性神经元胞体，但在胸交感干神经节以及腹腔-前肠系膜神经节中有大量的SP阳性纤维和终未．均无SP阳性胞体。分组切断与腹腔-前肠系膜神经节相联系的神经支后．该神经节内的SP仅在切断与背根节的联系后明显减少或消失。将HRP注入胸7-9（T7-9）背根节，在相应的胸交感干神经节和腹腔-前肠系膜神经节发现少量标记细胞。以上结果表明，交感节中的SP纤维来自背根节初级传入神经元的轴突侧支，交感节主细胞发出节后纤维投射于感觉节．感觉与交感节之间存在双向纤维联系。提示由初级传入神经元与交感节后神经元直接形成中枢外短反射环路．以调节自主神经的活动，且交感神经对外周一级传入信息有反馈调节作用。上述结果为阐明针刺机理提供了部分形态学证据。

A Study on the Reflex Arc Outside the Central Nervous System with Sympathetic Ganglia as the Centre

The distribution of SP-like immunoreactivity in the sensory and syrnpathetic ganglia, as well as the fiber connection between sensory ganglia and sympathetic ganglia (SG) were studied by the immunohistochemical ABC and HRP methods. A large numberpf SP-like neurons were found in all dorsal root ganglia (DRG), and a large nurnber of SP-like fibers and terminals were found in both thoracic SG and coeliac-cranial rnesenteric ganglion complex (CCMG), but no SP positive perikaryons were seen in those ganglia. The various nerves connected with the CCMG have been cut, the results demonstrate that the SP immunoreactive material in the ganglion were only decreased obviously or disappeared by cutting the DRG associatd with the CCMG. After injecting HRP into T7-9 DRG, a few of labelled neurons were found in thoracic SG of the relative segments and CCMG. The results mentioned above revealed that SP-Containing fibers and terminals present in the SG come from collateral branches of primary sensory neurons in the DRG, the postganglionic fibers from principal ganglion neurons in the SG projecting to the DRG f the connection of reciprocal fibers are present between the DRG and the SG. It is suggested that a reflex shortloop outside the central nervous system may be formed directly by primary afferent neuron and sympathetic postganglidnic neuron for the purpose of regulating the activity of autonomic nervous system and, moreover the sympathetic nerve may have a feedback regulation function to the primary afferent. The results mentioned above offer the partial morphological testimony for the expoundity of acupuncture mechanism.