Organization of descending neurons in Drosophila melanogaster
Organization of descending neurons in Drosophila melanogaster
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DOI：
10.1038/srep20259
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发表时间：
2016-02-03
影响因子：
4.6
通讯作者：
Bhandawat, Vikas
中科院分区：
文献类型：
--
作者：
Hsu, Cynthia T.;Bhandawat, Vikas
大脑中的神经处理通过下行神经元(DNS)控制行为--这些神经元将信号从大脑传递到脊髓(或昆虫的胸神经节)。因为糖尿病起源于大脑中的多个回路，遗传工具的简单性和可用性使果蝇成为理解下行运动控制的一个容易处理的模型。作为全面研究下行运动控制的第一步，我们在这里估计了果蝇大脑中神经元的数量和分布。我们通过将葡聚糖染料回填到颈部连接处来标记Dns，并估计在果蝇中有类似于1100个Dns分布在6个簇中。为了评估神经递质对神经递质的分布，我们标记了果蝇中表达主要神经递质的神经元。我们发现Dns属于我们测试的每一类神经递质：乙酰胆碱、GABA、谷氨酸、5-羟色胺、多巴胺和章鱼胺。主要的兴奋性神经递质(乙酰胆碱)和主要抑制性神经递质(GABA)都被同等使用；这与脊椎动物的神经递质形成对比，后者主要是兴奋性的。通过比较Dns在果蝇中的分布和以前在其他昆虫中的分布，我们得出结论：Dns在昆虫中的组织是高度保守的。
Neural processing in the brain controls behavior through descending neurons (DNs) - neurons which carry signals from the brain to the spinal cord (or thoracic ganglia in insects). Because DNs arise from multiple circuits in the brain, the numerical simplicity and availability of genetic tools make Drosophila a tractable model for understanding descending motor control. As a first step towards a comprehensive study of descending motor control, here we estimate the number and distribution of DNs in the Drosophila brain. We labeled DNs by backfilling them with dextran dye applied to the neck connective and estimated that there are similar to 1100 DNs distributed in 6 clusters in Drosophila. To assess the distribution of DNs by neurotransmitters, we labeled DNs in flies in which neurons expressing the major neurotransmitters were also labeled. We found DNs belonging to every neurotransmitter class we tested: acetylcholine, GABA, glutamate, serotonin, dopamine and octopamine. Both the major excitatory neurotransmitter (acetylcholine) and the major inhibitory neurotransmitter (GABA) are employed equally; this stands in contrast to vertebrate DNs which are predominantly excitatory. By comparing the distribution of DNs in Drosophila to those reported previously in other insects, we conclude that the organization of DNs in insects is highly conserved.