Distribution of chloride channel-2-immunoreactive neuronal and astrocytic processes in the hippocampus
Distribution of chloride channel-2-immunoreactive neuronal and astrocytic processes in the hippocampus
复制标题
DOI：
10.1016/s0306-4522(00)00360-2
复制
发表时间：
2000-01-01
期刊：
影响因子：
3.3
通讯作者：
Freund, TF
中科院分区：
文献类型：
--
作者：
Sík, A;Smith, RL;Freund, TF
神经元和非神经元细胞的氯稳态部分地通过氯通道-2的电压敏感性内向整流氯电导来维持。该通道被超极化和细胞外低渗激活。在本研究中，海马切片的氯离子通道-2免疫染色，锥体和非锥体细胞的胞体和树突被发现是免疫反应。此外，在小血管附近的神经胶质细胞的过程也进行了免疫染色，而神经鞘的层间质和腔隙-moleculare含有氯离子通道-2阳性点状结构。电子显微镜和双重免疫染色，使用抗氯离子通道-2，和胶质细胞酸性蛋白的抗体证实，密集的网络的氯离子通道-2-阳性过程对应于星形胶质细胞的端足。氯离子通道-2免疫反应阳性星形胶质细胞的分布是不均匀的整个海马：层oriens，cerebellale和腔隙-分子的CA 1-CA 3和齿状回的外分子层包含了大部分的免疫反应性尾足，而其他层显示稀疏的标记。亚细胞研究表明，除星形胶质细胞外，氯离子通道2还定位于树突、树突棘、细胞体和神经元轴突起始段的细胞膜上，经常靠近或位于对称性突触的活动区内，因此，氯离子通道2似乎参与了与GABA能突触传递相关的跨膜氯离子运动。氯离子通道-2阳性星形胶质细胞过程的特定层状分布与GABA能轴突终末的分布一致，表明星形胶质细胞网络可能能够虹吸并将Cl-离子输送到具有强烈GABA能传递的层。从而增加GABAA受体介导的抑制的功效。(C)2000 IBRO。由爱思唯尔科技有限公司出版。保留所有权利。
The chloride homeostasis of neurons and non-neuronal cells is maintained in part by a voltage-sensitive inwardly rectifying chloride conductance through the chloride channel-2. This channel is activated by hyperpolarization and extracellular hypotonicity. In the present study, hippocampal sections were immunostained for chloride channel-2, and somata and dendrites of both pyramidal and non-pyramidal cells were found to be immunoreactive. In addition, glial processes in the vicinity of small blood vessels were also immunostained, whereas the neuropil of strata pyramidale and lacunosum-moleculare contained chloride channel-2-positive punctate structures. Electron microscopy and double immunostaining using antibodies against chloride channel-2, and glial fibrillary acidic protein confirmed that the dense network of chloride channel-2-positive processes corresponds to the end feet of astrocytes. The distribution of chloride channel-2-immunoreactive astrocytes was inhomogeneous throughout the hippocampus: strata oriens, pyramidale and lacunosum-moleculare of CA1-CA3 and the outer molecular layer of the dentate gyrus contained the majority of immunoreactive end feet, whereas the other layers showed sparse labeling. Subcellular studies demonstrated that, in addition to astrocytes, chloride channel-2 was localized in the membrane of dendrites, dendritic spines, cell bodies and axon initial segments of neurons, frequently close to, or within active zones of, symmetrical synapses.Thus, chloride channel-2 appears to be involved in transmembrane chloride movements associated with GABAergic synaptic transmission. The specific laminar distribution of chloride channel-2-positive astroglial processes coinciding with that of GABAegic axon terminals suggests that the network of astrocytes may be able to siphon and deliver Cl- ions to layers with intense GABAergic transmission. thereby increasing the efficacy of GABAA receptor-mediated inhibition. (C) 2000 IBRO. Published by Elsevier Science Ltd. All rights reserved.