Luminance Changes Drive Directional Startle through a Thalamic Pathway
Luminance Changes Drive Directional Startle through a Thalamic Pathway
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DOI：
10.1016/j.neuron.2018.06.013
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发表时间：
2018-07-25
期刊：
影响因子：
16.2
通讯作者：
Scott, Ethan K.
中科院分区：
文献类型：
--
作者：
Heap, Lucy A. L.;Vanwalleghem, Gilles;Scott, Ethan K.
隐约可见的视觉刺激会导致从昆虫到人类的逃避反应。尽管它们对生存很重要，但介导视觉惊吓的回路直到最近才在脊椎动物中被探索。在这里，我们表明，斑马鱼丘脑是一个亮度检测器视觉逃避的关键。丘脑投射神经元向视顶盖传递特定的信息，这些投射的消融破坏了视顶盖对织机的正常反应。如果没有这些信息，幼虫就不太可能逃离黑暗的若隐若现的刺激，并失去逃离织机的能力。值得注意的是，当与对侧眼的等亮度织机刺激配对时，调暗足以增加惊吓概率，并逆转逃跑的方向，使其朝向织机。我们认为，从丘脑到顶盖的亮度双边比较有助于逃避反应，并且对其方向性至关重要。
Looming visual stimuli result in escape responses that are conserved from insects to humans. Despite their importance for survival, the circuits mediating visual startle have only recently been explored in vertebrates. Here we show that the zebrafish thalamus is a luminance detector critical to visual escape. Thalamic projection neurons deliver dim-specific information to the optic tectum, and ablations of these projections disrupt normal tectal responses to looms. Without this information, larvae are less likely to escape from dark looming stimuli and lose the ability to escape away from the source of the loom. Remarkably, when paired with an isoluminant loom stimulus to the opposite eye, dimming is sufficient to increase startle probability and to reverse the direction of the escape so that it is toward the loom. We suggest that bilateral comparisons of luminance, relayed from the thalamus to the tectum, facilitate escape responses and are essential for their directionality.