Ultrastructural analysis of climbing fiber-Purkinje cell synaptogenesis in the rat cerebellum
Ultrastructural analysis of climbing fiber-Purkinje cell synaptogenesis in the rat cerebellum
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DOI：
10.1016/s0306-4522(01)00433-x
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发表时间：
2001-01-01
期刊：
影响因子：
3.3
通讯作者：
Rosina, A
中科院分区：
文献类型：
--
作者：
Morara, S;Van der Want, JJL;Rosina, A
以前的报告已经描述了短暂的表达的神经肽降钙素基因相关肽和神经肽Y在选定的子集大鼠橄榄小脑车厢在胚胎和出生后的发展。使用这些神经肽作为橄榄小脑纤维的内源性标记物，该电子显微镜分析的目的是揭示从胚胎第19天到出生后第16天，在此期间浦肯野细胞经历树突的强烈发射和收缩，本研究首次提供了直接证据，证明爬行纤维突触发生始于胚胎第19天，且这些突触主要涉及浦肯野细胞膜细胞胚树突而不是浦肯野细胞索马。在相同的年龄，存在类似降钙素基因相关肽标记的突触在浦肯野细胞板的未标记的突触，使人们有可能得出结论，攀缘纤维形成一个主要的突触投资胚胎浦肯野细胞，这一发现，强烈支持的假说的早期分化作用的攀缘纤维小脑发育。此外，在强烈的浦肯野细胞的树突重塑期间，'髓鞘数字'经常检测到浦肯野细胞树突表明，他们可能至少部分代表真实的超微结构标记膜营业额确定的网站浦肯野细胞树突重排正在发生。最后，发现攀援纤维终端并列退化树突一般没有表现出退化的迹象，我们认为，攀援纤维易位从perisomatic树突的位置可能是驱动：浦肯野细胞树突重塑。(C)2001年IBRO。由爱思唯尔科技有限公司出版。保留所有权利。
Previous reports have described the transient expression of the neuropeptides calcitonin gene-related peptide and neuropeptide Y in selected subsets of rat olivocerebellar compartments during embryonic and postnatal development. Using these neuropeptides as endogenous markers for olivocerebellar fibers, the aim of this electron microscopic analysis was to reveal the synaptogenetic processes occurring between climbing fibers and their target Purkinje cells, from embryonic day 19 to postnatal day 16, the period during which Purkinje cells undergo intense emission and retraction of dendrites, and climbing fibers translocate their synapses along Purkinje cell membrane surfaces.The present findings provide the first direct evidence that climbing fiber synaptogenesis starts on embryonic day 19 and that these first synapses mainly involve the Purkinje cell embryonic dendrite rather than the Purkinje cell soma. At the same age, the presence of unlabeled synapses resembling calcitonin gene-related peptide-labeled synapses in the Purkinje cell plate makes it possible to conclude that climbing fibers form a major synaptic investment on embryonic Purkinje cells, a finding that strongly supports the hypothesis of an early differentiating role of climbing fibers on cerebellar development. Furthermore, during the period of intense dendritic remodeling of Purkinje cells, 'myelin figures' were often detected in Purkinje cell dendrites suggesting that they may at least in part represent real ultrastructural markers of membrane turnover that identifies the sites where Purkinje cell dendritic rearrangement is taking place. Finally the finding that the climbing fiber terminals apposed to degenerating dendrites did not generally show signs of degeneration leads us to suggests that climbing fiber translocation from a perisomatic to a dendritic location may be driven: by the Purkinje cell dendritic remodeling. (C) 2001 IBRO. Published by Elsevier Science Ltd. All rights reserved.