F-actin at identified synapses in the mushroom body neuropil of the insect brain
F-actin at identified synapses in the mushroom body neuropil of the insect brain
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DOI：
10.1002/cne.20165
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发表时间：
2004-07-26
影响因子：
2.5
通讯作者：
Schürmann, FW
中科院分区：
文献类型：
--
作者：
Frambach, I;Rössler, W;Schürmann, FW
本文研究了荧光鬼笔藻素染色的f-肌动蛋白在几种昆虫脑中的分布，特别是蘑菇体。用于本地化。F-肌动蛋白在已鉴定的神经元和突触处，采用右旋糖苷荧光染色和抗突触素I免疫组织化学染色。在蘑菇体的突触复合体(肾盏微球[MG])中可见较强的f-肌动蛋白染色。这些MG含有突触前突触的中央核心，主要属于中脑胆碱能兴奋性投射神经元，其周围环绕着大量的Kenyon细胞(KC)树突尖端。高分辨率激光共聚焦扫描成像显示，在蟋蟀双斑羚体内，f-肌动蛋白与KC树突棘部分共定位于MG内。尽管突触前突触前突触主要缺乏f-肌动蛋白-鬼臼蛋白荧光，但在与突触突触接触的KC树突棘中，似乎有大量的f-肌动蛋白聚集。电子显微镜下观察到KC树突的突触前和突触后的位置，其中KC是严格意义上的突触后成分。它们的突触下膜对位被认为与f-肌动蛋白有关。如蟋蟀、蜜蜂、蚂蚁和果蝇的蘑菇体一样，肌动蛋白在树突顶端的局灶性聚集是MG的一个普遍特征，有大小不一的球状或锯齿状。比较分析了KC树突和小脑微球中肾盏MG和f-肌动蛋白积聚的结构相似性。从蘑菇体的可塑性及其在学习和记忆形成中的潜在作用的角度，讨论了f-肌动蛋白在KC树突中的积累。(C)2004年Wiley-Liss公司
The distribution of f-actin stained by fluorescent phalloidin was investigated in the brain of several insect species, with a special focus on the mushroom body. For localizing. f-actin in identified neurons and at synapses, additional staining with fluorescent dextrans and anti-synapsin I inummostaining was employed. Intense f-actin, staining was consistently found in synaptic complexes of the mushroom body calyces (calycal microglomeruli [MG]). These MG contain a central core of presynaptic boutons, predominantly belonging to deutocerebral cholinergic excitatory projection neurons, which are surrounded by a shell of numerous Kenyon cell (KC) dendritic tips. In the cricket Gryllus bimaculatus, high-resolution confocal laser scanning imaging revealed colocalization of f-actin with KC dendritic spine parts within MG. Although presynaptic boutons appear to be mainly devoid of f-actin-phalloidin fluorescence, there appears to be an accumulation of f-actin in KC dendritic spines synaptically contacting the boutons. Electron microscopy of boutons and dextran-stained KC dendrites revealed their pre- and postsynaptic sites, with KCs being strictly postsynaptic elements. Their subsynaptic membrane appositions are considered to be associated with f-actin. Focal accumulation of f-actin in the dendritic tips of KCs was found to be a general feature of MG, with either spheroidal or indented boutons of different sizes, as encountered in the mushroom bodies of the cricket, honey bee, ant, and fruit fly. The structural similarities of calycal MG and f-actin accumulation in KC dendrites with cerebellar microglomeruli are considered comparatively. The accumulation of f-actin in KC dendrites is discussed in view of mushroom body plasticity and its potential role in learning and memory formation. (C) 2004 Wiley-Liss, Inc.