REGIONAL SPECIALIZATION IN SYNAPTIC INPUT AND OUTPUT IN AN IDENTIFIED LOCAL NONSPIKING INTERNEURON OF THE CRAYFISH REVEALED BY LIGHT AND ELECTRON-MICROSCOPY
REGIONAL SPECIALIZATION IN SYNAPTIC INPUT AND OUTPUT IN AN IDENTIFIED LOCAL NONSPIKING INTERNEURON OF THE CRAYFISH REVEALED BY LIGHT AND ELECTRON-MICROSCOPY
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DOI：
10.1002/cne.902510305
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发表时间：
1986-09-15
影响因子：
2.5
通讯作者：
HISADA, M
中科院分区：
文献类型：
--
作者：
KONDOH, Y;HISADA, M
小龙虾末端神经节中几个机械感觉中间神经元的侧向抑制是由一对被称为局部定向选择(LDS)中间神经元的局部非尖峰中间神经元介导的。用辣根过氧化物酶细胞内标记技术对这些中间神经元的超微结构和突触分布进行了电子显微镜观察。LDS中间神经元有双侧的不对称分支。它们由粗大的横状突起连接，上面没有形成突触。胞体同侧的突起光滑，几乎接受全部的输入突触。另一方面，对侧神经突起有明显的大量肿胀或曲张，从中长出许多短而细的棘突，输入和输出突触交织在一起。然而，这两种突触并不总是与精索静脉曲张和脊椎相关。LDS中间神经元的突触前突触在突触特化附近仅含有圆形无颗粒突触小泡。这些形态发现与这个中间神经元的生理学很好地相关：它在功能上两极分化，在神经节的一侧(与细胞体同侧)接受输入，并将其传送到另一侧。
Lateral inhibition of several mechanosensory interneurons in the crayfish terminal ganglion is mediated by a pair of identified local nonspiking interneurons called local directionally selective (LDS) interneurons. The ultrastructure and synaptic distribution of these interneurons were investigated by using intracellular labeling with horseradish peroxidase for electron microscopy. The LDS interneuron has bilateral, asymmetric arborizations. They are connected by thick transverse neurite on which no synapses are made. The neurites on the side ipsilateral to the cell body are smooth and receive almost entirely input synapses. On the other hand, the contralateral neurites have prominent numerous swellings or varicosites from which many short fine spines arise, with intermingled input and output synapses. Both synapses, however, are not always associated with varicosites and spines. Presynaptic neurites of the LDS interneuron contain only round agranular synaptic vesicles in the vicinity of synaptic specializations. These morphological findings correlate well with the physiology of this interneuron: it is functionally polarized to receive input on one side (ipsilateral to the cell body) of the ganglion and convey it to the other side.