【摘要】 <正> P物质在中枢神经系统内起着神经递质的作用已经是公认的事实。然而,要彻底明瞭其作用机制则必须在超微结构水平上进行研究。这方面的工作在文献上虽有一些报道, 但对其在神经细胞各种超微结构中的分布则研究很少,尤其对感觉性核团的轴轴突触(这种突触被认为是突触前抑制的形态学基础)中P物质的分布缺乏详细的资料。本文试图通过特异性的超微免疫细胞更多还原

【Abstract】 The ultrastructural localization of substance P in the spinal trigeminal nucleus of the rat has been studied by means of immuno-electronmicroscopic method. Besides identifying substance P immunoreaction occurred in large granular vesicles and surrounding small lucent vesicles and the outer membrane of mitochondrion, the results showed mainly the distribution of substance P immunoreaction in different types of synapse, i.e., the presynaptic terminals of Gray type-1 axodendritic synapse, the presynaptic terminals of AA, type axoaxonic synapse and the postsynaptic terminals of AA2 type axoaxonic synapse as well as the granular type axoaxonic synapse, including pre- and postsynaptic terminals.On the basis of the experimental results mentioned above and scientific data, the authors suggest that substance P- containing Gray type-i axodendritic synapse might belong to excitatory one; substance P- containing AAt axoaxonic synapse might be the relay stop of primary pain impulse; substance P-containing AAZ axoaxonic synapse may be considered as morphological basis of presynaptic inhibition; and substance P contained in the granular type axoaxonic synapse seems likely to have dual algesic and analgesic actions.更多还原