Classification of Object Size in Retinotectal Microcircuits
Classification of Object Size in Retinotectal Microcircuits
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DOI：
10.1016/j.cub.2014.09.012
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发表时间：
2014-10-20
期刊：
影响因子：
9.2
通讯作者：
Bollmann, Johann H.
中科院分区：
文献类型：
--
作者：
Preuss, Stephanie J.;Trivedi, Chintan A.;Bollmann, Johann H.
背景：视觉系统的主要任务是检测和分类视觉环境中的移动物体。有关物体大小的信息对于选择适当的行为反应至关重要。物体大小由视网膜神经节细胞 (RGC) 活动编码。然而，关于来自多种 RGC 亚型的输入如何分布到更高的视觉中心以及如何从这些特征选择性输入中组合信息，人们知之甚少。结果：在这里，我们表明，在斑马鱼视顶盖中，猎物或捕食者样的移动目标会根据目标尺寸在不同的 RGC 纤维组中引起活动，这证明了顶盖尺寸分类的视网膜起源。小尺寸选择性视网膜输入在顶盖神经纤维的最表层相对更频繁，而大尺寸选择性输入在更深的层中占主导地位。单层浅层中间神经元（SIN）根据其树突目标层处理大尺寸和小尺寸选择性信号，与视网膜输入组织一致。再往下游，小型和大型物体被编码在不同顶盖神经元组的群体活动中。结论：与行为学相关的尺寸类别优先在顶盖神经元的不同层中进行处理。顶盖根据视网膜计算的尺寸信息对视觉目标进行分类，这表明在视觉引导的反应选择中发挥着关键作用。
Background: A principal task of the visual system is to detect and classify moving objects in the visual environment. Information about the size of an object is critical for selecting appropriate behavioral responses. Object size is encoded in retinal ganglion cell (RGC) activity. Little is known, however, about how inputs from the multitude of RGC subtypes are distributed to higher visual centers and how information is combined from these feature-selective inputs.Results: Here we show that in the zebrafish optic tectum, prey- or predator-like moving targets evoke activity in distinct groups of RGC fibers dependent on target size, demonstrating a retinal origin of tectal size classification. Small-size-selective retinal inputs are relatively more frequent in the most superficial layer of the tectal neuropil, whereas large-size-selective inputs predominate in deeper layers. Monostratified superficial interneurons (SINs) process large-size- and small-size-selective signals dependent on their dendritic target layer, consistent with the retinal input organization. Further downstream, small- and large-sized objects are encoded in population activity of separate sets of tectal neurons.Conclusions: Ethologically relevant size classes are preferentially processed in different layers of the tectal neuropil. The tectum categorizes visual targets on the basis of retinally computed size information, suggesting a critical role in visually guided response selection.