The color-vision circuit in the medulla of Drosophila
The color-vision circuit in the medulla of Drosophila
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DOI：
10.1016/j.cub.2008.02.075
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发表时间：
2008-04-22
期刊：
影响因子：
9.2
通讯作者：
Desplan, Claude
中科院分区：
文献类型：
--
作者：
Morante, Javier;Desplan, Claude
背景：色觉需要对不同光波长敏感的光感受器之间进行比较。在果蝇中，这是通过含有不同视紫红质的内部光感受器（R7和R8）实现的。果蝇的色觉中可能出现两种比较类型：在一个小眼（单眼单元）内的R7（对紫外线敏感）和R8（对蓝色或绿色敏感）光感受器细胞之间，或者在含有不同光谱特性内部光感受器的不同小眼之间。光感受器投射到视叶：参与运动检测的R1 - R6投射到神经纤维网，而R7和R8则深入到髓质。本文分析了色觉进入髓质的神经网络。
结果：我们重建了髓质中的神经网络，重点关注可能参与色觉处理的神经元。我们确定了髓质中神经元的全部组成，包括与单个小眼的R7和R8都有接触，或者与不同小眼的R7和/或R8有接触的二级神经元。我们还研究了三级神经元和可能调节二级神经元信息的局部神经元。最后，我们展示了高度特异性的工具，这些工具将使我们能够对网络进行功能性操作，并测试其活性和行为。
结论：对髓质回路的这种精确描述将使我们能够理解果蝇视叶中色觉是如何被处理的，为脊椎动物中更复杂的系统提供了范例。
Background: Color vision requires comparison between photoreceptors that are sensitive to different wavelengths of light. In Drosophila, this is achieved by the inner photoreceptors (R7 and R8) that contain different rhodopsins. Two types of comparisons can occur in fly color vision: between the R7 (UV sensitive) and R8 (blue- or green sensitive) photoreceptor cells within one ommatidium (unit eye) or between different ommatidia that contain spectrally distinct inner photoreceptors. Photoreceptors project to the optic lobes: R1-R6, which are involved in motion detection, project to the lamina, whereas R7 and R8 reach deeper in the medulla. This paper analyzes the neural network underlying color vision into the medulla.Results: We reconstruct the neural network in the medulla, focusing on neurons likely to be involved in processing color vision. We identify the full complement of neurons in the medulla, including second-order neurons that contact both R7 and R8 from a single ommatidium, or contact R7 and/or R8 from different ommatidia. We also examine third-order neurons and local neurons that likely modulate information from second-order neurons. Finally, we present highly specific tools that will allow us to functionally manipulate the network and test both activity and behavior.Conclusions: This precise characterization of the medulla circuitry will allow us to understand how color vision is processed in the optic lobe of Drosophila, providing a paradigm for more complex systems in vertebrates.