• Title/Summary/Keyword: Retinal mosaic

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Populations of Rod and Cone Photoreceptors in the Hamster Retina (햄스터 망막에서의 광수용체 분포)

  • Yu, Song-Hee;Kim, Hyun-Jin;Lee, Kyoung-Pil;Lee, Eun-Shil;Lee, Jea-Young;Jeon, Chang-Jin
    • Applied Microscopy
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    • v.39 no.4
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    • pp.291-299
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    • 2009
  • We report on a quantitative analysis of cone and rod photoreceptors in hamster retina. Cone and rod photoreceptors were counted in retinal whole mounts using differential interference contrast (DIC) optics microscopy after staining of cone photoreceptors were stained with peroxidase-labeled peanut lectin. Middle-to-long-wave-sensitive-(M/L-), and shortwave-sensitive-(S-) cone opsins were visualized by observed using confocal microscope after immunocytochemical procedure. The average cone density was 9,307 $cells/mm^2$, giving a total of cones of 293,060 cone cells per retina. The peak density of cone cells (12,857 $cells/mm^2$) was found 0.3 mm from the optic disk (OD) of the nasal retina. The average rod density was 300,082 $cells/mm^2$, giving a total number of rods of 9,448,150 cells. The peak density of rod cells was found 0.3 mm from the OD of the dorsal retina. Of all photoreceptors studied, the total percentage of rods and cones were 96.99% and cones 3.01%, respectively. The mean ratio of rod and cone was 32.24 : 1. The cone photoreceptors of hamster contained both M/L- and S-cone opsins. The present results suggest that the hamster retina is strongly rod-dominated with some photopic property of vision.

Study on the Visual Cells in the Retina of Macropodus ocellatus (Pisces, Osphronemidae) Freshwater Fish from Korea (한국산 담수어류 버들붕어, Macropodus ocellatus (Pisces, Osphronemidae) 망막의 시각세포에 관한 연구)

  • Kim, Jae Goo;Park, Jong Yong
    • Korean Journal of Ichthyology
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    • v.29 no.3
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    • pp.218-223
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    • 2017
  • Using both light and scanning electron microscopies, it was investigated on the visual cells as well as the eyes of Macropodus ocellatus (Pisces, Osphronemidae). This species had a circular lens and yellowish cornea. The eyes had $3.5{\pm}0.2mm$ which is $31.1{\pm}3.0%$ in a percentage of eye diameter relative to head length. The retina ($158.2{\pm}10.6{\mu}m$) was built of several layers, including the visual cell layer which consists of three types of cells: single cons ($27.8{\pm}1.6{\mu}m$) and equal double cone ($33.9{\pm}3.7{\mu}m$), and large rods ($57.3{\pm}1.3{\mu}m$). The visual cell layer then was classified into the correct pattern. All visual cells were clearly distinguished from two parts (inner and outer segments). The elongated rod cells were extend to the bottom of the retinal pigment epithelium. In scanning electron microscopy, the outer segment links to inner segment by so-called calyceal piles. The M. ocellatus single and double cones appearance form a flower-petal arrangement, which is a regular mosaic pattern that contains quadrilateral units by four double cones surrounding a single cone.