Chandelier cells in rat visual cortex
Chandelier cells in rat visual cortex
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大鼠视觉皮层的吊灯细胞
DOI：
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发表时间：
1982
期刊：
影响因子：
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通讯作者：
C. Ribak
中科院分区：
文献类型：
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作者：
A. Peters;C. C. Proskauer;C. Ribak
用光镜和电子显微镜观察了大鼠视皮质内高尔基体染色的枝形吊灯细胞。所有受孕的枝形吊灯细胞的细胞体都在II/III层内，尽管它们出现在整个第17区，但在17/18a区边界的数量增加，在17/18区边界的数量较少。大多数枝形吊灯细胞是被咬伤的神经元，有成群的树突从细长细胞体的上下两极延伸，但一些细胞具有更多的多极配置。核周细胞质中含有丰富的粗面内质网，胞体和疏松的棘状树突接受轴突终末，形成对称性和非对称性突触。这些神经元的轴突要么来自细胞体的下极，要么来自下丛中一个树突的底部，轴突形成横向扩展的神经丛，终止于垂直的突起串。每条线的胞突与第II/III层锥体细胞的轴突起始段发生突触，最上面的胞体距离锥体7~14μm。一些II/III层锥体细胞似乎接受来自多个枝形吊灯细胞的突起，另一些来自单个枝形吊灯细胞，还有一些似乎没有接受枝形吊灯细胞终末。枝形吊灯细胞的轴突末端形状不规则，含有多形性突触小泡，形成对称性突触。有证据表明，具有与吊灯细胞相同的形态特征和突触终止位置的轴突终末含有谷氨酸脱羧酶(GAD)，GAD是合成GABA的酶。因此，吊灯细胞可能是GABA能的抑制性神经元。其他GAD阳性轴突终末与胞体、轴突丘和II/III层锥体细胞轴突起始段的近端突触，这些终末可能来自光滑疏松的棘状星状细胞。
Golgi‐impregnated chandelier cells in rat visual cortex have been examined by both light and electron microscopy. All of the chandelier cells impregnated have their cell bodies within layer II/III and although they occur throughout area 17, there are increased numbers at the area 17/18a border and to a lesser extent at the area 17/18 border. Most of the chandelier cells are bitufted neurons, with groups of dendrites extending from the upper and lower poles of an elongate cell body, but some cells have a more multipolar configuration. The perikaryal cytoplasm is rich in rough endoplasmic reticulum and both the cell body and the sparsely spinous dendrites receive axon terminals forming symmetric and asymmetric synapses. The axons of these neurons arise from either the lower pole of the cell body or the base of one of the dendrites in the lower tuft, and the axons form laterally spread plexuses which terminate in vertical strings of boutons. The boutons in each string synapse with axon initial segments of layer II/III pyramidal cells, the uppermost bouton in each string being 7 to 14 μm distant from the pyramidal cell body. Some layer II/III pyramidal cells seem to receive boutons from more than one chandelier cell, others from a single chandelier cell, and still others appear to receive no chandelier cell terminals. The axon terminals of the chandelier cells are irregular in shape, contain pleomorphic synaptic vesicles, and form symmetric synapses. Evidence is presented to show that axon terminals exhibiting the same morphological features and site of synaptic termination as those of the chandelier cells contain glutamic acid decarboxylase (GAD), the enzyme which synthesizes GABA. Hence the chandelier cells are probably GABAergic, inhibitory neurons. Other GAD‐positive axon terminals synapse with the cell bodies, axon hillocks, and proximal portions of the axon initial segments of the layer II/III pyramidal cells, and these terminals are probably derived from the smooth and sparsely spinous stellate cells.