The Drosophila larval visual system: high-resolution analysis of a simple visual neuropil.
The Drosophila larval visual system: high-resolution analysis of a simple visual neuropil.
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果蝇幼虫视觉系统：简单视觉神经纤维的高分辨率分析。
DOI：
10.1016/j.ydbio.2011.07.006
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发表时间：
2011
影响因子：
2.7
通讯作者：
Hartenstein,Volker
中科院分区：
文献类型：
--
作者：
Sprecher,SimonG;Cardona,Albert;Hartenstein,Volker
视觉系统的任务是将光转化为神经元编码的信息。这种将光子转化为神经元信号的过程是由位于眼睛中的感光神经元（PR），即专门的感觉神经元实现的。当感知到光时，PR将向目标神经元发送信号，这代表视觉处理的第一站。视觉处理的日益复杂性源于不同PR亚型的数量及其接触的各种类型的靶神经元。果蝇幼虫的视觉系统代表了一个简单的视觉系统（幼虫视神经元，LON），其由12个PR组成，分为两类：表达视紫红质5（Rh5）的蓝色敏感PR和表达视紫红质6（Rh6）的绿色敏感PR。这些传入神经接触少量的靶神经元，包括视叶先驱神经元（OLP）和外侧时钟神经元（LN）。我们结合联合收割机使用遗传标记来标记PR亚型和不同的，可识别的靶神经元与一系列EM重建，以产生高分辨率的地图的幼虫视神经元。我们发现，幼虫的视神经元显示出一个明确的二分组织由一个域支配的PR和一个没有PR轴突。PR投射的拓扑结构，特别是Rh5和Rh6传入之间的关系，是从进入大脑的神经到轴突终末维持的。靶神经元可以根据它们使用的神经递质或神经肽以及在大脑中的位置进行细分。我们进一步跟踪幼虫的视神经元，通过发展从第一龄幼虫到其在成人大脑中的位置作为副髓质。
The task of the visual system is to translate light into neuronal encoded information. This translation of photons into neuronal signals is achieved by photoreceptor neurons (PRs), specialized sensory neurons, located in the eye. Upon perception of light the PRs will send a signal to target neurons, which represent a first station of visual processing. Increasing complexity of visual processing stems from the number of distinct PR subtypes and their various types of target neurons that are contacted. The visual system of the fruit fly larva represents a simple visual system (larval optic neuropil, LON) that consists of 12 PRs falling into two classes: blue-senstive PRs expressing Rhodopsin 5 (Rh5) and green-sensitive PRs expressing Rhodopsin 6 (Rh6). These afferents contact a small number of target neurons, including optic lobe pioneers (OLPs) and lateral clock neurons (LNs). We combine the use of genetic markers to label both PR subtypes and the distinct, identifiable sets of target neurons with a serial EM reconstruction to generate a high-resolution map of the larval optic neuropil. We find that the larval optic neuropil shows a clear bipartite organization consisting of one domain innervated by PRs and one devoid of PR axons. The topology of PR projections, in particular the relationship between Rh5 and Rh6 afferents, is maintained from the nerve entering the brain to the axon terminals. The target neurons can be subdivided according to neurotransmitter or neuropeptide they use as well as the location within the brain. We further track the larval optic neuropil through development from first larval instar to its location in the adult brain as the accessory medulla.