Avian cone photoreceptors tile the retina as five independent, self-organizing mosaics.
Avian cone photoreceptors tile the retina as five independent, self-organizing mosaics.
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DOI：
10.1371/journal.pone.0008992
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发表时间：
2010-02-01
期刊：
影响因子：
3.7
通讯作者：
Corbo JC
中科院分区：
文献类型：
--
作者：
Kram YA;Mantey S;Corbo JC
鸟类视网膜拥有脊椎动物中最复杂的视锥细胞感光系统之一。鸟类有五种类型的视锥细胞，包括四种单视锥细胞（支持四色色视觉）和一种双视锥细胞（被认为可以调节消色差运动感知）。尽管如此丰富，但人们对鸟类视锥细胞的空间组织及其适应性意义知之甚少。在这里，我们展示了鸡的五种视锥细胞类型独立地将视网膜平铺为高度有序的马赛克，同一类型的视锥细胞之间具有特征间距。拓扑顺序的测量表明，双锥体比单锥体具有更高的有序性，这可能反映了它们在运动检测中的既定作用。尽管视锥细胞显示出细胞类型特异性的间距相互作用，但所有视锥细胞类型都使用相同的密度依赖性尺度来测量视锥细胞间的距离。我们提出了一个简单的发展模型来解释这些观察结果。我们还表明，单个参数（全局规律性指数）定义了所有五个锥体马赛克的规律性。最后，我们在另外三种鸟类中展示了类似的锥体分布，这表明这些图案原理在鸟类中是普遍存在的。由于规则的感光器间距对于视觉空间的均匀采样至关重要，因此鸟类视网膜的锥形马赛克代表了一个优雅的例子，说明继发于个体感光器之间简单的局部相互作用之后出现的自适应全局图案。我们的结果表明，进化压力导致鸟类视网膜产生各种增强颜色辨别力的适应，也起到了微调其颜色和亮度空间采样的作用。
The avian retina possesses one of the most sophisticated cone photoreceptor systems among vertebrates. Birds have five types of cones including four single cones, which support tetrachromatic color vision and a double cone, which is thought to mediate achromatic motion perception. Despite this richness, very little is known about the spatial organization of avian cones and its adaptive significance. Here we show that the five cone types of the chicken independently tile the retina as highly ordered mosaics with a characteristic spacing between cones of the same type. Measures of topological order indicate that double cones are more highly ordered than single cones, possibly reflecting their posited role in motion detection. Although cones show spacing interactions that are cell type-specific, all cone types use the same density-dependent yardstick to measure intercone distance. We propose a simple developmental model that can account for these observations. We also show that a single parameter, the global regularity index, defines the regularity of all five cone mosaics. Lastly, we demonstrate similar cone distributions in three additional avian species, suggesting that these patterning principles are universal among birds. Since regular photoreceptor spacing is critical for uniform sampling of visual space, the cone mosaics of the avian retina represent an elegant example of the emergence of adaptive global patterning secondary to simple local interactions between individual photoreceptors. Our results indicate that the evolutionary pressures that gave rise to the avian retina's various adaptations for enhanced color discrimination also acted to fine-tune its spatial sampling of color and luminance.
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DOI：
10.1007/s00359-001-0240-3
发表时间：
2001-11-01
影响因子：
2.1
作者：
Hart, NS
通讯作者：
Hart, NS
影响因子：
1.9
作者：
CURCIO, CA;SLOAN, KR
通讯作者：
SLOAN, KR
DOI：
10.1016/s0022-5320(66)80013-8
发表时间：
1966-01-01
期刊：
JOURNAL OF ULTRASTRUCTURE RESEARCH
影响因子：
--
作者：
DUNN, RF
通讯作者：
DUNN, RF
影响因子：
3.4
作者：
Galli-Resta, L;Novelli, E;Reese, BE
通讯作者：
Reese, BE
影响因子：
1.9
作者：
Eglen, Stephen J.;Wong, James C. T.
通讯作者：
Wong, James C. T.