Neural Circuit Components of the Drosophila OFF Motion Vision Pathway
Neural Circuit Components of the Drosophila OFF Motion Vision Pathway
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DOI：
10.1016/j.cub.2014.01.006
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发表时间：
2014-02-17
期刊：
影响因子：
9.2
通讯作者：
Borst, Alexander
中科院分区：
文献类型：
--
作者：
Meier, Matthias;Serbe, Etienne;Borst, Alexander
背景：检测视觉运动的方向是早期视觉系统的一项基本任务。Reichardt检测器已被证明是昆虫底层计算的忠实描述。最近的一系列研究讨论了果蝇中Reichardt检测器的神经实现，揭示了平行的ON和OFF通道的总体布局，其输入神经元来自板层（L1 -> ON，L2 -> OFF），以及各自的输出神经元到小叶板（ON -> T4，OFF -> T5）。虽然解剖学研究表明T4细胞通过Mi 1和Tm 3细胞接收来自L1的输入，但迄今为止尚未确定连接L2和T5细胞的神经元。然而，它是已知的，L2接触，除其他外，两个神经元，称为Tm 2和L4，这表明在他们的wiring.Results的一个明显的方向性：我们的特点Tm 2和L4神经元的视觉反应特性通过钙离子成像。我们发现，Tm 2和L4细胞的活动增加，以方向非选择性的方式移动关闭边缘。为了研究它们在运动视觉中的参与，我们阻断了它们的输出，同时从小叶板中的下游切向细胞记录。沉默的Tm 2和L4完全废除的响应移动OFF的edge.Conclusions：我们的研究结果表明，这两种细胞类型的果蝇OFF运动视觉通路的重要组成部分，在T5细胞的树突的方向性的计算之前。
Background: Detecting the direction of visual motion is an essential task of the early visual system. The Reichardt detector has been proven to be a faithful description of the underlying computation in insects. A series of recent studies addressed the neural implementation of the Reichardt detector in Drosophila revealing the overall layout in parallel ON and OFF channels, its input neurons from the lamina (L1 -> ON, and L2 -> OFF), and the respective output neurons to the lobula plate (ON -> T4, and OFF -> T5). While anatomical studies showed that T4 cells receive input from L1 via Mi1 and Tm3 cells, the neurons connecting L2 to T5 cells have not been identified so far. It is, however, known that L2 contacts, among others, two neurons, called Tm2 and L4, which show a pronounced directionality in their wiring.Results: We characterized the visual response properties of both Tm2 and L4 neurons via Ca2+ imaging. We found that Tm2 and L4 cells respond with an increase in activity to moving OFF edges in a direction-unselective manner. To investigate their participation in motion vision, we blocked their output while recording from downstream tangential cells in the lobula plate. Silencing of Tm2 and L4 completely abolishes the response to moving OFF edges.Conclusions: Our results demonstrate that both cell types are essential components of the Drosophila OFF motion vision pathway, prior to the computation of directionality in the dendrites of T5 cells.