大鼠弓状核内神经紧张素能和P物质能阳性结构的免疫电镜双标记研究

A DOUBLE LABELED IMMUNOELECTRON MICROSCOPIC STUDY OF NEUROTENSINERGIC AND SUBSTANCE P-ERGIC STRUCTURES IN THE RAT ARCUATE NUCLEUS

用包埋前免疫电镜双标记技术研究大鼠下丘脑内的神经紧张素(NT)和P物质(SP)分布的超微结构。证实在弓状核内存在NT样和SP样免疫反应阳性的胞体、树突和轴突。NT样和SP样免疫反应阳性的树突和轴突均可接受免疫反应阴性结构的非对称性传入突触。SP样免疫反应阳性轴突终末除可与免疫反应阴性的树突和胞体形成对称性传出突触外, 还可与NT样免疫反应阳性胞体形成对称性轴-体突触。本研究首次直接证实大鼠弓状核内的NT能神经元接受SP能神经的支配。

The distributions of neurotensin(NT) and substance P(SP) in the arcuate nucleus of rat hypothalamus have been studied by means of double labeled pre-embedding immunoelectron microscopic technique. It was observed that there were SP- and NT-containing dendrites, perikarya and axons in the arcuate nucleus. SP- and NT-containing dendrites and axons received asymmetric afferent synapses from immunonegative axons. SP-positive axonal terminals established symmetric axo-somatic and axo-dendritic synapses with immunonegative perikarya and dendrites as well as symmetric axo-somatic synapses with NT-positive perikarya. The results of this study directly indicate for the first time that the NT-ergic neurons in rat arcuate nucleus receive innervation from SP-ergic neurons, and provided an ultrastructural evidence for the synaptic regulation of the neuroendocrine of the hypothalamus.