Chromatic information processing in the first optic ganglion of the butterfly Papilio xuthus
Chromatic information processing in the first optic ganglion of the butterfly Papilio xuthus
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DOI：
10.1007/s00359-019-01390-w
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发表时间：
2020-03-01
影响因子：
2.1
通讯作者：
Arikawa, Kentaro
中科院分区：
文献类型：
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作者：
Chen, Pei-Ju;Belusic, Gregor;Arikawa, Kentaro
凤蝶（Papilio xuthus）具有敏锐的四色色觉。它的眼睛配备了八个光谱类的感光器，位于三种类型的小眼，随机分布在视网膜马赛克。在这里，我们研究了早期的彩色信息处理记录光谱，角度和偏振感光细胞和板单极细胞（LMCs）的敏感性。我们确定了三个光谱类的LMCs的光谱灵敏度对应于加权线性总和的感光细胞的光谱灵敏度存在于三个小眼类型。在~ 25%的感光轴突中，光谱灵敏度与感光细胞体处记录的光谱灵敏度不同。这些轴突表现出光谱反射，最有可能介导的氯离子电流通过组胺能感光器间突触。在延髓的长视纤维突起中，这种变化最为明显。我们重新计算的波长歧视功能，使用噪声限制的双折射模型，以反映新的光谱灵敏度数据，发现它匹配以及与行为确定的功能。我们的研究结果揭示了在第一阶段的凤蝶的视觉系统，表明光谱信息预处理的信号从光感受器内的每个小眼在薄板，然后被传送下游的长视觉纤维和LMCs。
The butterfly Papilio xuthus has acute tetrachromatic color vision. Its eyes are furnished with eight spectral classes of photoreceptors, situated in three types of ommatidia, randomly distributed in the retinal mosaic. Here, we investigated early chromatic information processing by recording spectral, angular, and polarization sensitivities of photoreceptors and lamina monopolar cells (LMCs). We identified three spectral classes of LMCs whose spectral sensitivities corresponded to weighted linear sums of the spectral sensitivities of the photoreceptors present in the three ommatidial types. In ~ 25% of the photoreceptor axons, the spectral sensitivities differed from those recorded at the photoreceptor cell bodies. These axons showed spectral opponency, most likely mediated by chloride ion currents through histaminergic interphotoreceptor synapses. The opponency was most prominent in the processes of the long visual fibers in the medulla. We recalculated the wavelength discrimination function using the noise-limited opponency model to reflect the new spectral sensitivity data and found that it matched well with the behaviorally determined function. Our results reveal opponency at the first stage of Papilio's visual system, indicating that spectral information is preprocessed with signals from photoreceptors within each ommatidium in the lamina, before being conveyed downstream by the long visual fibers and the LMCs.