Photic input pathways that mediate the Drosophila larval response to light and circadian rhythmicity are developmentally related but functionally distinct
Photic input pathways that mediate the Drosophila larval response to light and circadian rhythmicity are developmentally related but functionally distinct
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DOI：
10.1002/cne.20383
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发表时间：
2005-01-17
影响因子：
2.5
通讯作者：
Campos, R
中科院分区：
文献类型：
--
作者：
Hassan, J;Iyengar, B;Campos, R
介导对光反应的果蝇幼虫感光器官由两侧对称的12个光感受器组成。这些基于视紫红质Rh 5和Rh 6的表达来区分。Rh 6-表达细胞对应于Hofbauer-Buchner（H-B）神经元，后来在成年复眼的后缘发现，最近被证明在成年果蝇昼夜节律的夹带中起输入途径的作用。此外，幼虫光感受器的轴突被发现与位于发育中的副髓质中的主要昼夜节律起搏神经元的子集，小腹侧神经元（LNv）密切相关。观察到的昼夜节律电路，输入通路，起搏神经元和幼虫的视觉器官的组件之间的空间重叠表明这两个感光输入通路之间的功能关系。在这项研究中，我们确定了特定的视紫红质表达的光感受器，包括推定的H-B神经元和起搏神经元的幼虫运动反应的视觉刺激的需求。我们的研究结果表明，两个最重要的组成部分的神经元电路的昼夜节律在果蝇，即视网膜外的H-B集群和昼夜节律的起搏器，而在密切相关的幼虫视觉系统是不需要的幼虫运动响应光。(C)2004 Wiley-Liss，Inc.
The Drosophila melanogaster larval photosensory organ that mediates the response to light consists of bilaterally symmetrical clusters of 12 photoreceptors. These are distinguished on the basis of expression of the rhodopsins Rh5 and Rh6. The Rh6-expressing cells correspond to the Hofbauer-Buchner (H-B) eyelet found later in the posterior margin of the adult compound eye and recently shown to function as an input pathway in the entrainment of circadian rhythmicity in adult Drosophila. In addition, the axons of the larval photoreceptors are found in intimate association with a subset of the main circadian pacemaker neurons located in the developing accessory medulla, the small ventral lateral neurons (LNv). The observed spatial overlap between components of the circadian circuitry, input pathway, and pacemaker neurons-and the larval visual organ-suggest a functional relationship between these two photosensory input pathways. In this study we determined the requirement of specific rhodopsin-expressing photoreceptors including the presumptive H-B eyelet and pacemaker neurons in the larval locomotory response to visual stimuli. Our results demonstrate that two of the most important components of the neuronal circuitry underlying circadian rhythmicity in Drosophila, namely, the extraretinal H-B cluster and the circadian pacemakers, while in intimate association with the larval visual system are not required for the larval motor response to light. (C) 2004 Wiley-Liss, Inc.