Selective localization of high concentrations of F-Actin in subpopulations of dendritic spines in rat central nervous system: A three-dimensional electron microscopic study
Selective localization of high concentrations of F-Actin in subpopulations of dendritic spines in rat central nervous system: A three-dimensional electron microscopic study
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DOI：
10.1002/cne.1199
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发表时间：
2001-06-25
影响因子：
2.5
通讯作者：
Ellisman, MH
中科院分区：
文献类型：
--
作者：
Capani, F;Martone, ME;Ellisman, MH
树突棘在大脑不同区域的大小、形状和内部组织都有很大的不同。我们利用一种基于phalloidin对丝状肌动蛋白(F)高亲和力的新型高分辨率光转换方法，在光镜和电子显微镜水平上检测了海马（CA1、CA3和齿状回区域）、新纹状体和小脑树突棘中的肌动蛋白细胞骨架。在所有脑区，标记在树突棘的头部最强，在脊柱颈部减弱。标记棘的数量因区域而异。小脑分子层和CA3区几乎所有树突棘都被标记，而CA1区、齿状回区和新纹状体区标记的棘不到一半。对这些区域棘的连续切片重建表明，phalloidin标记仅限于最大和形态最多样化的树突棘。光转换技术的分辨率使我们能够检查脊柱中肌动蛋白丝的定位和组织。肌动蛋白染色最强烈的部位是突触后密度，与脊髓内膜系统有关。在蘑菇状的脊柱中，f -肌动蛋白染色在脊柱器官的片层之间特别强烈。利用电子断层扫描对标记后的脊髓进行三维重建，发现标记后的致密物质与突触后的致密物质具有连续性。这些结果突出了不同脊柱种群之间肌动蛋白细胞骨架的差异，并为体内肌动蛋白细胞骨架的组织提供了新的信息。(C) 2001 Wiley-Liss, Inc。
Dendritic spines differ considerably in their size, shape, and internal organization between brain regions. We examined the actin cytoskeleton in dendritic spines in hippocampus (areas CA1, CA3, and dentate gyrus), neostriatum, and cerebellum at both light and electron microscopic levels by using a novel high-resolution photoconversion method based in the high affinity of phalloidin for filamentous (F)-actin. In all brain regions, labeling was strongest in the heads of dendritic spines, diminishing in the spine neck. The number of labeled spines varied by region. Compared with the cerebellar molecular layer and area CA3, where nearly every dendritic spine was labeled, less than half the spines were labeled in CA1, dentate gyrus, and neostriatum. Serial section reconstructions of spines in these areas indicated that phalloidin labeling was restricted to the largest and most morphologically diverse dendritic spines. The resolution of the photoconversion technique allowed us to examine the localization and organization of actin filaments in the spine. The most intense staining for actin was found in the postsynaptic density and associated with the spines internal membrane system. In mushroom-shaped spines, F-actin staining was particularly strong between the lamellae of the spine apparatus. Three-dimensional reconstruction of labeled spines by using electron tomography showed that the labeled dense material was in continuity with the postsynaptic density. These results highlight differences in the actin cytoskeleton between different spine populations and provide novel information on the organization of the actin cytoskeleton in vivo. (C) 2001 Wiley-Liss, Inc.