猫后索核内后根初级传入终末与丘脑投射神经元间的突触联系

The Synaptic Relationships Between the Primary Afferent Terminals and Thalamic Projecting Neurons in the Cat Dorsal Column Nuclei

为确立后索核内初级传入终末与丘脑投射神经元间的突触联系,本文采用顺行溃变与 HRP 逆行追踪相结合的方法,在电镜水平对后索核内初级传入终末与丘脑投射神经元间的突触联系组合形式进行了研究。结果表明,后索核内有6种突触联系形式:(1)溃变轴突终末与 HRP 标记树突形成轴—树突触;(2)溃变轴突终末与 HRP 标记胞体形成轴—体突触;(3)溃变轴突终末及正常轴突终末与标记的中央树突形成汇聚型突触复合体;(4)轴—轴—树连续性突触;(5)溃变轴突终末与非标记树突形成轴—树突触;(6)非溃变的含扁平小泡或多形态小泡轴突终末与 HRP 标记的神经元胞体形成轴—体突触.本研究首次报道了猫后根初级传入终末与后索核丘脑投射神经元间的直接突触联系。突触形式计有轴—树和轴—体突触及以树突为中心的突触复合体.本研究结果为阐明后索核内非伤害性信息传递与整合的作用方式提供了直接的突触学基础。

In order to establish the Synaptic relationship between the primary afferent terminals and thalamic projecting neurons inthedorsal column nuclei(DCN),the combined retrograde transport of horseradish peroxidase(HRP)and experimentaldegeneration,have been applied in the cats.The results showed that six types synapses were observed in the DCN by electron microscope.(1)degenerating axonalterminals made axo—dendritic synapses with cabelled dendrites;(2)degenerating axonal terminals made axo—somatic synapses with labelled newronal perikarya;(3)degenerating axonal terminals and normal axonal terminals together Constitute Synaptic cmplex with the central Labelled dendrite;(4)degenerating terminals were presynaptic to dendrites,and were themselves postsynaptic to small axon terminals con- taining flattened vesicles;(5)degenerating terminals made axo—dendritic synapses with un- labelled dendrites;(6)normal axonal terminals containing flattened made axo—somatic synapses with labelled newronal perikaryon.