猫孤束核胶状质亚核的突触构筑学研究

THE STUDY OF SYNAPSOARCHITECTURE OF THE SUBNUCLEUS GELATINOSUS OF THE SOLITARY NUCLEUS IN THE CAT

用透射电镜对猫的孤束核胶状质亚核(SNG)的突触型式进行了观察,除看到已报导的轴—树突触、轴—体突触、树—树突触外,还发现该核内含有轴—轴突触及突触球等结构。SNG内轴—树突触最常见,而轴—体突触、轴—轴突触和树—树突触则较少。各类突触中的突触囊泡多为圆形清亮囊泡,而扁平清亮囊泡和大颗粒囊泡较少。扁平清亮囊泡多与圆形清亮囊泡共存于同一轴—轴突触终末内。轴—轴突触均为对称型突触,有时与树突或胞体相连形成轴—轴—树突触或轴—轴—体突触。突触球多为以树突和棘为中心的中心树突型突触球。此外在SNG内还观察到嵴突触,并联突触等连接形式。SNG内突触的复杂性表明传入冲动在该核中可能经过扩散、汇聚和突触前抑制等多种复杂的整合过程调节内脏活动。

The ultrastructure of the synapses in cat subuncleus gelatinosus of solitary nucleus(SNG)was studied under electron microscope.Axoaxonic synapses and synaptic glomeruli are seen in SNG besides the axodendritic,axosomatic and dendrodendritic synapses,as reported before.The number of axodendritic synapses in SNG is much larger than that of axosomatic,axoaxonic,and dendrodendritic synapses.More round trasparent vesicles are found in various types of synapses,less flat transparent and large granular ones.The flat transparent and round transparent vesicles usually coexist in axonic terminals.Almost all of the axoaxanic synapses appear to be of symmetrical type,the postsynaptic elements of which sometimes synapse with another dendrite or soma to form an axoaxodendritic or axoaxosomatic synapse.There are synaptic glomeruli with central dendrite cr spine.At the same time,crest er parallel synapses are also found in SNG.The complexity of the ultrastructure and types of synapse in SNG implies that integration in SNG might include diffusion,convergence and presynaptic inhibition of afferent impulses,and also reflects that the regulations of visceral activity by the solitary nucleus are complicated.