三叉神经脊束核内SP神经的单胺神经支配——化学损毁及免疫细胞化学电镜研究

本文应用化学损毁与免疫细胞化学相结合的方法在亚细胞水平研究了SP神经的单胺神经支配。结果证实在大鼠三叉神经脊束核尾侧亚核内广泛存在着因5,7—DHT损毁所致的变性单胺(主要是5-HT)神经纤维和SP样免疫反应的树突和轴突。单胺能神经和SP样神经结构可分别与未标记的结构形成突触联系。而且,在这两种不同化学性质的神经结构之间存在着轴—树和轴—轴突触。在所有这些突触结构中,单胺能神经末梢均为突触前成分,SP终扣则为突触后成分。突触前、后膜大多呈对称性。以上实验结果可以为解释单胺(主要是5-HT)帮SP在三叉神经脊束核尼侧亚核中参与疼痛和镇痛的机制提供超微结构依据。

THE MONOAMINERGIC INNERVATION OF SUBSTANCE P NERVE IN THE SPINAL NUCLEUS OF TRIGEMINAL NERVE—COMBINED CHEMICAL LESION AND IMMUNOCYTOCHEMISTRY WITH ELECTRON MICROSCOPIC STUDY

The monoaminergic innervation of substance P nerve was studied by combined method of chemical lesion and immunocylochemistry at subcellular level. The results showed that the degenerated monoaminergic (mainly serotonergic) nerve fibers induced by 5, 7-dihydroxytryptamine (5, 7-DHT) and substance P(SP)-like immtunoreactive dendrites and axons distributed widely in the caudal spinal nucleus of trigeminal nerve. The monoaminergic and SP-LI nervous structures formed synaptic connections with unlabeled structures respectively. Meanwhile, the axodendritic and axo-axonic synapses existed between the above chemically identified two kinds of nervous structures. In all these cases, the monoaminergic nerve terminals served as presynaptic elements, whereas the SP-LI boutons postsynaptic elements. The pre-and postsynaptic membrane are mainly symmetrical. The experimental results mentioned above might provide ultrastructure evidence to explain the mechanism of monoamine (mainly serotonin) and SP in pain and analgesia in the caudal spinal nucleus of trigeminal nerve