Clonal unit architecture of the adult fly brain
Clonal unit architecture of the adult fly brain
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DOI：
10.1007/978-0-387-78261-4_9
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发表时间：
2008-01-01
期刊：
影响因子：
--
通讯作者：
Awasaki, Takeshi
中科院分区：
文献类型：
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作者：
Ito, Kei;Awasaki, Takeshi
在幼虫的神经发生过程中，神经母细胞重复不对称的细胞分裂，产生克隆相关的后代。当单个神经母细胞的后代在幼虫脑中可见时，它们的细胞体形成簇，它们的神经突形成紧密的束。这种结构在成年人的大脑中仍然存在。从这一簇细胞中衍生出来的神经突形成神经束，支配大脑的不同区域。这种克隆单位结构首先在蘑菇体中发现;蘑菇体由四个几乎相同的克隆单位形成，每个克隆单位由不同类型的神经元组成。大脑其他区域的组织结构，如中央复合体和触角叶投射神经元，也由不同的克隆单位组成。在大脑的其他部分也可以观察到许多克隆相关的神经回路，这些神经回路通常被称为弥散神经堆，因为它们明显缺乏明确划分的结构。因此，克隆单位很可能是成年人大脑回路的重要组成部分。然而，克隆单位的分支并不相互排斥。相反，几个克隆单位一起形成不同的神经回路单位，其他克隆的贡献相对较小。在发育和进化过程中，通过组合这些克隆相关单位来构建大脑，是构建复杂神经回路的一种简单而有效的策略。
During larval neurogenesis, neuroblasts repeat asymmetric cell divisions to generate clonally related progeny. When the progeny of a single neuroblast is visualized in the larval brain, their cell bodies form a cluster and their neurites form a tight bundle. This structure persists in the adult brain. Neurites deriving from the cells in this cluster form bundles to innervate distinct areas of the brain. Such clonal unit structure was first identified in the mushroom body; which is formed by four nearly identical clonal units each of which consists of diverse types of neurons. Organised structures in other areas of the brain, such as the central complex and the antennal lobe projection neurons, also consist of distinct clonal units. Many clonally related neural circuits are observed also in the rest of the brain, which is often called diffused neuropiles because of the apparent lack of clearly demarcated structures. Thus, it is likely that the clonal units are the building blocks of a significant portion of the adult brain circuits. Arborisations of the clonal units are not mutually exclusive, however. Rather, several clonal units contribute together to form distinct neural circuit units, to which other clones contribute relatively marginally. Construction of the brain by combining such groups of clonally related units would have been a simple and efficient strategy for building the complicated neural circuits during development as well as during evolution.