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SYNAPSE FORMATION AND GROWTH IN AN AUTONOMIC GANGLION

自主神经节中突触的形成和生长

基本信息

批准号：
3408437
负责人：
PETER B. SARGENT
金额：
$ 6.33万
依托单位：
UNIVERSITY OF CALIFORNIA RIVERSIDE
依托单位国家：
美国
项目类别：
财政年份：
1986
资助国家：
美国
起止时间：
1986-03-01 至 1989-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3408437
关键词：
Xenopus acetylcholinesterase autonomic ganglion cell growth regulation innervation larva mature animal metamorphosis neural information processing neuroanatomy neurogenesis neurophysiology preganglionic fiber synapses tissue mosaicism

项目摘要

The long-range objective of my research is to understand the mechanisms that underlie the formation of synapses between neurons during embryogenesis. The specific objectives of this proposal are 1) to complete an analysis of synaptic growth in the cardiac ganglion of postmetamorphic Xenopus laevis and 2) to study the initial formation and the growth of synapses on developing cardiac ganglion cells in larval animals. In mature animals the innervation of individual neurons is dominated by a preganglionic axon which supplies all the synaptic boutons found on the ganglion cell body. During postmetamorphic life the total area of synaptic contact grows by an increase in bouton number, and the increase in bouton number is exactly matched by an increase in ganglion cell size. By studying transmitter release from the principal synaptic input to ganglion cells and by counting boutons on physiologically characterized cells, we shall determine whether boutons represent equivalent amounts of transmitter release and whether they represent the functional unit of synaptic growth. By studying the innervation of both diploid and larger tetraploid ganglion cells in chimeric animals, we hope to determine the basis of the compensatory growth of cell size and bouton number in postmetamorphic animals. The arrival of preganglionic axons in the developing cardiac ganglion will be visualized by filling techniques, and nascent synapses will be studied both anatomically and physiologically. How do the structure and release properties of newly formed boutons compare with those of mature ones? The growth of synapses in larval animals will be analyzed to learn whether boutons are the units of synaptic growth from the very onset of synaptogenesis. Synapse elimination will be investigated by physiological techniques, and we shall ask whether the ganglion cell body is ever innervated by more than one preganglionic axon. Finally, we shall search for transient connections between ganglion cells. Such connections are ordinarily suppressed by preganglionic innervation but may appear early in development. These studies will increase our understanding of how synapses between neurons form and grow during development. They will also identify the stages when the process of synapse formation may go awry.

我的研究的长期目标是了解这些机制这是神经元之间突触形成的基础胚胎发生。本提案的具体目标是：1)完成变态后心脏神经节内突触生长的分析 2)研究非洲爪哇的初始形成和生长。幼年动物心脏神经节细胞发育中的突触。成熟期动物单个神经元的神经支配由一种节前轴突，它提供了在神经节细胞体。在变性后生命中，突触的总面积联系随着Bouton数量的增加和Bouton数量的增加而增长这一数字与神经节细胞大小的增加完全匹配。通过主要突触传入神经节的递质释放研究通过对具有生理特征的细胞进行计数，我们发现应确定波顿是否代表等量的发射机释放以及它们是否代表突触生长的功能单位。二倍体和较大四倍体神经节的神经支配在嵌合动物中的细胞，我们希望确定基础变质后细胞大小和数量的补偿性生长动物。神经节前轴突到达发育中的心脏神经节将通过填充技术进行可视化，并将研究新生突触解剖学和生理学上都是如此。如何构建和发布新形成的粒子的性质与成熟粒子的性质作了比较？这个将对幼年动物的突触生长进行分析，以了解突触是突触生长的单位，从突触开始突触发生。突触消除将通过生理学研究技术，我们将问神经节细胞体是否曾经由不止一个节前轴突支配。最后，我们将搜索用于神经节细胞之间的瞬时连接。这样的联系是通常由节前神经支配抑制，但可能出现在早期发展。这些研究将增加我们对突触是如何神经元在发育过程中形成和生长。他们还将确定突触形成过程可能出错的阶段。