Visual adaptations in a diurnal rodent, Octodon degus
Visual adaptations in a diurnal rodent, Octodon degus
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DOI：
10.1007/s00359-003-0408-0
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发表时间：
2003-05-01
影响因子：
2.1
通讯作者：
Williams, GA
中科院分区：
文献类型：
--
作者：
Jacobs, GH;Calderone, JB;Williams, GA
德古（学名：Degu degus）是一种昼行性啮齿动物，原产于智利。通过一系列解剖、电生理和行为实验研究了该物种视觉和视觉组织的基本特征。德古眼的透镜选择性地吸收短波长的光，并显示出作为年龄的函数的光密度的逐渐增加。使用闪烁光度法记录的视网膜电图揭示了三种光谱机制：具有约500 nm的峰值灵敏度的视杆和具有约362 nm和507 nm的各自的光谱峰值的两种类型的视锥。用视蛋白抗体标记法测定三种受体在视网膜的分布。在德古视网膜的大约900万个光感受器中，总共约三分之一是两种类型（507 nm/ 362 nm）以约13：1的比例表示的视锥。在一系列的行为实验中检查了所有三种受体类型对视觉的贡献。电生理和行为结果的一致特征是，需要相对高水平的光适应来实现从基于视杆的视觉到基于视锥的视觉的完全过渡。在行为测试中，degus被证明能够区分紫外线和可见光的颜色。
The degu (Octodon degus) is a diurnal rodent, native to Chile. Basic features of vision and visual organization in this species were examined in a series of anatomical, electrophysiological and behavioral experiments. The lens of the degu eye selectively absorbs short-wavelength light and shows a progressive increase in optical density as a function of age. Electroretinograms recorded using a flicker-photometric procedure reveal three spectral mechanisms: a rod with peak sensitivity of about 500 nm and two types of cone having respective spectral peaks of about 362 nm and 507 nm. Opsin antibody labeling was used to determine the retinal distributions of the three receptor types. A total of about one-third of the approximately 9 million photoreceptors of the degu retina are cones with the two types (507 nm/ 362 nm) represented in a ratio of about 13:1. The contributions to vision of all three receptor types were examined in a series of behavioral experiments. A consistent feature of both the electrophysiological and behavioral results is that relatively high levels of light adaptation are required to effect the full transition from rod-based to cone-based vision. In behavioral tests degus were shown to be able to make color discriminations between ultraviolet and visible lights.