Comparative visual function in elasmobranchs: Spatial arrangement and ecological correlates of photoreceptor and ganglion cell distributions
Comparative visual function in elasmobranchs: Spatial arrangement and ecological correlates of photoreceptor and ganglion cell distributions
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DOI：
10.1017/s0952523808080693
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发表时间：
2008-07-01
影响因子：
1.9
通讯作者：
Collin, Shaun P.
中科院分区：
文献类型：
--
作者：
Litherland, Lenore;Collin, Shaun P.
视网膜神经节和感光细胞分布的地形分析为评估脊椎动物的视觉能力和行为生态学提供了有价值的信息。本研究探讨了四个板鳃类物种，华丽的wobbegong，Orectolobus ornatus;白鳍礁鲨，Triaenodon obesus;肩章鲨的整个安装的视网膜。眼斑半萼藓;和东澳大利亚铲鼻鳐，Aptychotrema rostrata，为区域专业化调解区的改善视觉能力。这些物种代表了一系列的生活方式：海底、中层水。白天和夜间。在视网膜中的光感受器（可视化使用差分干涉对比光学）和神经节细胞（用甲酚紫染色）被广泛采样，发现它们的空间分布是不均匀的。表现出区域或“视觉条纹”。“一般来说，两种细胞群的地形分布，都与高密度区域的位置相匹配。然而，视杆细胞和视锥细胞密度峰值的位置在视网膜内可能不同，这表明在明视觉和暗视觉中可能发生视野不同区域的优先采样。解析力光学极限的解剖测量。由锥间间距表示，范围为3.8至13.1周/度。从神经节细胞间距计算的分辨力的空间限制范围为2.6至4.3周期/度。通过直接比较视网膜上150多个不同位点的光感受器（输入细胞）和神经节细胞（输出细胞）的细胞密度来评估的总和比显示出信号会聚的地形差异（范围从25：1到70：1以上）。
The topographic analysis of retinal ganglion and photoreceptor cell distributions yields valuable information for assessing the visual capabilities and behavioral ecology of vertebrates. This study examines whole-mounted retinas of four elasmobranch species, the ornate wobbegong, Orectolobus ornatus; the whitetip reef shark, Triaenodon obesus; the epaulette shark. Hemiscyllium ocellatum; and the east Australia shovelnose ray, Aptychotrema rostrata, for regional specializations mediating zones of improved visual ability. These species represent a range of lifestyles: benthic, mid-water. diurnal, and nocturnal. Both photoreceptors (visualized using differential interference contrast optics) and ganglion cells (stained with cresyl violet) in the retina are extensively sampled, and their spatial distribution is found to be nonuniform. exhibiting areae or "visual streaks." In general, the topographic distribution,; of both cell populations are in register and match well with respect to the location of regions of high density. However, the location of peaks in rod and cone densities can vary within a retina, indicating that preferential sampling of different regions of the visual field may Occur in photopic and scotopic vision. Anatomical measures of the optical limits of resolving power. indicated by intercone spacing, range from 3.8 to 13.1 cycles/deg. Spatial limits of resolving power, calculated from ganglion cell spacing, range from 2.6 to 4.3 cycles/deg. Summation ratios, assessed by direct comparison of cell densities of photoreceptors (input cells) and ganglion cells (output cells), at more than 150 different loci across the retina, show topographic differences in signal convergence (ranging from 25:1 to over 70:1 Species-specific retinal specializations strongly correlate to the habitat and feeding behavior of each species.