Diverse Food-Sensing Neurons Trigger Idiothetic Local Search in Drosophila
Diverse Food-Sensing Neurons Trigger Idiothetic Local Search in Drosophila
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DOI：
10.1016/j.cub.2019.03.004
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发表时间：
2019-05-20
期刊：
影响因子：
9.2
通讯作者：
Dickinson, Michael H.
中科院分区：
文献类型：
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作者：
Corfas, Roman A.;Sharma, Tarun;Dickinson, Michael H.
觅食动物在继续探索附近时可能会受益于记住新发现的食物块的位置 [1, 2]。例如，在遇到一滴酵母或糖后，饥饿的苍蝇通常会进行局部搜索 [3, 4]。也就是说，苍蝇不是停留在食物上或简单地走开，而是执行一系列探索性的旅行，在此期间它们反复离开并返回资源。果蝇（Drosophila melanogaster）可以在没有外部标志的情况下执行这种以食物为中心的搜索行为，而不是依赖内部（愚蠢的）线索[5]。这种路径整合行为可能代表了昆虫中高度保守的导航能力 [6, 7]，但其潜在的神经基础仍然未知。在这里，我们使用光遗传学激活来筛选候选细胞类别，发现局部搜索可以由不同的感觉神经元发起。光遗传学诱导的搜索类似于由实际食物触发的搜索，受饥饿状态调节，并表现出路径整合的关键特征。即使在有限的迷宫内，苍蝇也会在虚构的食物地点周围进行紧密集中的搜索，并且它们可以在长途旅行后返回虚构的食物地点。总之，这些结果表明，果蝇会根据各种与食物相关的线索进行局部搜索，并且这些感觉通路可能会汇聚到一个共同的神经系统上进行导航。使用虚拟现实系统，我们证明可以在球形跑步机上行走的系留果蝇中通过光遗传学诱导局部搜索，为未来研究在路径整合过程中对大脑进行成像奠定了基础。
Foraging animals may benefit from remembering the location of a newly discovered food patch while continuing to explore nearby [1, 2]. For example, after encountering a drop of yeast or sugar, hungry flies often perform a local search [3, 4]. That is, rather than remaining on the food or simply walking away, flies execute a series of exploratory excursions during which they repeatedly depart and return to the resource. Fruit flies, Drosophila melanogaster, can perform this food-centered search behavior in the absence of external landmarks, instead relying on internal (idiothetic) cues [5]. This path-integration behavior may represent a deeply conserved navigational capacity in insects [6, 7], but its underlying neural basis remains unknown. Here, we used optogenetic activation to screen candidate cell classes and found that local searches can be initiated by diverse sensory neurons. Optogenetically induced searches resemble those triggered by actual food, are modulated by starvation state, and exhibit key features of path integration. Flies perform tightly centered searches around the fictive food site, even within a constrained maze, and they can return to the fictive food site after long excursions. Together, these results suggest that flies enact local searches in response to a wide variety of food-associated cues and that these sensory pathways may converge upon a common neural system for navigation. Using a virtual reality system, we demonstrate that local searches can be optogenetically induced in tethered flies walking on a spherical treadmill, laying the groundwork for future studies to image the brain during path integration.