SYNAPTIC TARGETS OF HRP-FILLED LAYER-III PYRAMIDAL CELLS IN THE CAT STRIATE CORTEX
SYNAPTIC TARGETS OF HRP-FILLED LAYER-III PYRAMIDAL CELLS IN THE CAT STRIATE CORTEX
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DOI：
10.1007/bf00340492
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发表时间：
1986-01-01
影响因子：
2
通讯作者：
SOMOGYI, P
中科院分区：
文献类型：
--
作者：
KISVARDAY, ZF;MARTIN, KAC;SOMOGYI, P
关于锥体细胞轴突侧支的作用有多种假设。大多数假设预测锥体细胞激活特定类别的突触后细胞。我们研究了两层 III 锥体细胞的突触后靶标，这些靶标特别令人感兴趣，因为它们的丛集轴突树状结构靠近细胞体，并且距离细胞体 0.4-1.0 nm，在 III 层和 V 层中都对齐。通过电子显微镜分析了来自四个位点（III 层和 V 层，在细胞柱中和远处团块中）的 191 个末端。只有一个按钮接触了细胞体，并且对 GABA 具有免疫反应。主要目标是树突棘（84％和87％），其余是树突轴。其中13个被分类为锥体状(P)，8个被分类为光滑细胞状(S)，并且无法分类。五种 S 型中的四种，但所测试的七种 P 型中没有一种对 GABA 具有免疫反应性，支持了精细结构分类。因此，假定的抑制细胞形成的突触后靶标不超过 5%，并且它们的激活只能通过锥体细胞汇聚到选定的 GABA 细胞群上来实现。结果表明，这里研究的具有丛集轴突的锥体细胞类型主要与其他锥体细胞接触。因此，柱内和柱间侧支系统的主要作用是激活其他兴奋性细胞。
There are numerous hypotheses for the role of the axon collaterals of pyramidal cells. Most hypotheses predict that pyramidal cells activate specific classes of postsynaptic cells. We have studied the postsynaptic targets of two layers III pyramidal cells, that were of special interest because of their clumped axon arborization near, and also 0.4-1.0 nm from the cell body, in register in both layers III and V. 191 terminations from four sites (layers III and V, both in the column of the cell and in distant clumps) were analysed by electron microscopy. Only one bouton contacted a cell body and that was immunoreactive for GABA. The major targets were dendritic spines (84 and 87%), and the remainder were dendritic shafts. Of these 13 were classed as pyramidal-like (P), 8 smooth cell-like (S) and there could not be classified. Four of five S types, but none of the seven P types tested were immunoreactive for GABA, supporting the fine structural classification. The putative inhibitory cells therefore formed not more than 5% of the postsynaptic targets, and their activation could only take place through the convergence of pyramidal cells onto a select population of GABA cells. The results show that the type of pyramidal cells with clumped axons studied here make contacts predominantly with other pyramidal cells. Thus the primary role of both the intra and intercolumnar collateral systems is the activation of other excitatory cells.