Journal ArticleDOI
Symmetry in a receptor mosaic demonstrated in the chick from the frequencies, spacing and arrangement of the types of retinal receptor
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A statistical analysis showed that each type of receptor was evenly spaced in the receptor mosaic, but single cone type I tended to occur in pairs.Abstract:
The mean percentages of receptors in the central retina were 14% rods, 32% double cones and 54% single cones. The mean percentages in the periphery were 33% rods, 30% double cones and 37% single cones. Single cones were classified into type I, type II and type III and the ratio of these types was about 5:2:1, respectively, in both central and peripheral retina. A statistical analysis showed that each type of receptor was evenly spaced in the receptor mosaic, but single cone type I tended to occur in pairs. The types of receptor were arranged in a pattern which was in the form of a hexagonal lattice. The pattern in the mosaic is regarded as the outcome of an evenly spaced distribution of the types of receptor. Perhaps pattern in the receptor mosaics of other vertebrate retinae should be interpreted as evenly spaced distributions of the types of receptor present. A method for detecting pattern in receptor mosaics, in which pattern is obscure, is described. A scheme accounting for the formation of the pattern in the chick retina during development is proposed.read more
Citations
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Chemistry and metabolism of lipids in the vertebrate retina
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Development of the Drosophila retina, a neurocrystalline lattice
TL;DR: Genetic mosaics show that the cells of each ommatidium are not derived from a single mother cell; the cells appear to be recruited at random at the morphogenetic front.
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The mosaic of nerve cells in the mammalian retina.
Heinz Wässle,H J Riemann +1 more
TL;DR: All four cell types were - independent of density - more regularly arranged in the centre of the retina than in the periphery and the advantages of a regular arrangement compared with a random distribution and mechanisms which could generate a regular mosaic are discussed.
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Ultraviolet Vision in Birds
Innes C. Cuthill,Julian C. Partridge,Andrew T. D. Bennett,Stuart C. Church,Nathan S. Hart,Sarah Hunt +5 more
TL;DR: This chapter discusses a range of behavioral experiments, from several species, which show that UV information is utilized in behavioral decisions, notably in foraging and signaling, and emphasizes that avian and human color perceptions are different and that the use of human color standards, and even artificial lighting, may produce misleading results.
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TL;DR: Using cumulative labeling method, cytogenesis of chick retina was studied by H3-thymidine autoradiography and the followings were concluded.
Journal ArticleDOI
An electron microscope study of types of receptor in the chick retina.
Valerie B. Morris,C. D. Shorey +1 more
TL;DR: Rods, double cones which comprise a principal and an accessory cone, and two types of single cones occur in the chick retina, and another type of synaptic body, which is not that of a receptor, occurs in the outer plexiform layer.