Developmental relocation of presynaptic terminals along distinct types of dendritic filopodia
Developmental relocation of presynaptic terminals along distinct types of dendritic filopodia
复制标题
DOI：
10.1016/j.ydbio.2006.05.012
复制
发表时间：
2006-09-01
影响因子：
2.7
通讯作者：
Duch, C.
中科院分区：
文献类型：
--
作者：
Evers, J. F.;Muench, D.;Duch, C.
树突状丝状伪足是主要发生在发育中的神经元上的细长突起。来自不同系统的数据表明丝状伪足在中枢神经回路形成中的一系列重要功能，包括引导树突生长、分支形成、突触发生和棘发生。是否同一丝状伪足有能力调节所有这些过程，是否丝状伪足通过发育获得不同的功能，或者是否存在具有不同功能的不同丝状伪足类型？在这项研究中，从共聚焦图像堆栈的三维重建表明存在两种形态和功能不同类型的丝状伪足位于树突尖端与树突轴相同的发展中运动神经元。在树枝状生长过程中，两种丝状伪足类型都经历了特定阶段的形态发生过程。使用新的量化策略的三维共定位分析免疫细胞化学标记的突触前专业化沿着突触后丝状伪足，我们发现，突触前终端积累沿着丝状伪足向树突在两个稳定的树突轴和不断增长的树突尖端。在尖端，这可能反映了树突的突触营养生长。在稳定的轴，然而，突触前网站成为重新定位沿着丝状伪足向树突状分支。这表明在突触发生过程中，以丝状伪足为向导，突触前和突触后的伙伴相互作用。(c)2006年爱思唯尔公司All rights reserved.
Dendritic filopodia are long thin protrusions occurring predominantly on developing neurons. Data from different systems suggest a range of crucial functions for filopodia in central circuit formation, including steering of dendritic growth, branch formation, synaptogenesis, and spinogenesis. Are the same filopodia competent to mediate all these processes, do filopodia acquire different functions through development, or do different filopodial types with distinct functions exist? In this study, 3-dimensional reconstructions from confocal image stacks demonstrate the existence of two morphologically and functionally distinct types of filopodia located on the dendritic tips versus the dendritic shafts of the same developing motoneuron. During dendritic growth, both filopodial types undergo a process of stage-specific morphogenesis. Using novel quantification strategies of 3-dimensional co-localization analysis for immunocytochemically labeled presynaptic specializations along postsynaptic filopodia, we find that presynaptic terminals accumulate along filopodia towards the dendrites at both stable dendritic shafts and on growing dendritic tips. On tips, this is likely to reflect synaptotrophic growth of the dendrite. At stable shafts, however, presynaptic sites become relocated along filopodia towards dendritic branches. This indicates the interactive growth of both pre- and postsynaptic partner towards one another during synaptogenesis, using filopodia as guides. (c) 2006 Elsevier Inc. All rights reserved.