皮质—脑桥核—小脑通路的HRP结合溃变电镜法研究

目的：观察大鼠脑桥核内皮质纤维终末的溃疡变型及其与脑桥核小脑投射神经元的突触联系方式，方法：采用HRP逆行标记结合溃变电镜技术。结果：（1）皮质纤维终末出现电子致密和微丝增生两种溃变类型。以电子致密型为主。后者终末又有两种不同形态，即含圆形清亮型小泡和多形清亮型小泡者，以圆形清亮型小泡终末占优势。（2）皮质纤维终末与脑桥核小脑投射神经元形成轴－树和少量轴－体突触，部分溃变终末与HRP标记的投射神经元形成单突触联系，结论：皮质纤维与脑桥核小脑投射神经元间存在的单突触联系构成了皮持－脑桥核－小脑通路。

AN ELECTRON-MICROSCOPIC STUDY USING HORSERADISH PEROXIDASE TRACING COMBINED WITH DEGENERATIONS METHOD ON THE CEREBRO PONTO CEREBELLAR PATHWAY

Objective:To observe the the degenerating mode of cortical fiber terminals and their synaptic connections with cerebellar projection neurons in pontine nucleus (PN).Methods:The HRP tracing and degenerating methods comibined with electron microscopic technique were used in the preeset study .Results:(1)It was seen in PN that the degenerated cortical fiber terminals had different amount,shape and distribution,most of them belong to electron dense degeneration,a few were filamentous.The electron dense degenerating terminals contained round clear vesicles or pleomorphic vesicles.For most part of them were the terminals contained round vesicles.(2)The degenerated terminals formed axo dendritic or axo somatic synapses with PN.A part of the degenerated terminals formed monosynaptic contacted with HRP labelled dendrites.Conclusion:The cortico pn cerebellar system includes 2 projections:corticopontine and pontocerebellar projections.A part of them form cortico pn cerebellar pathway by monosynaptic connectin.