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Light absorbed by 575-cones trigger rod disc shedding in the frog retina

Published online by Cambridge University Press:  02 June 2009

William C. Gordon
Affiliation:
Department of physiology and Cell Biology, University of Kansas, Lawrence
Nancy A. Dahl
Affiliation:
Department of physiology and Cell Biology, University of Kansas, Lawrence

Abstract

Photoreceptors periodically shed light-sensitive membranes; rods at light onset, cones at night. The spectral characteristics of light required to initiate shedding by 502-rods were studied in the frog retina. After 24 h of white light, animals were dark primed for 1 h then presented with 1 h of nearly monochromatic light to induce the shedding response. The light delivered a total photon flux of 2.5 or 0.5 μE/m2s. Following conventional fixation and plastic embedding, 1 μm sections were examined with light microscopy. The number of photoreceptor tips (phagosomes) shed by 100 consecutive rods were counted and plotted as a function of wavelength. Bright light induced at least 15 phagosomes per 100 rods at all wavelengths tested, 420−640 nm, and this shedding was more than doubled with light from 540−600 nm. When the light was dimmed, there was no shedding response except for this 540−600 nm window. This shedding peak closely corresponds to the absorbance curve of the frog's 575-cone photopigment and implies that the 575-cone can drive rod shedding. The broad background effect further indicates that all photoreceptors have an input and suggests that a luminosity cell, such as the internal horizontal cell, may be involved.

Type
Short Communication
Copyright
Copyright © Cambridge University Press 1990

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References

Basinger, S.F. & Gordon, W.C. (1982). Local stimulation induces shedding throughout the frog retina. Vision Reserch 22, 15331538.CrossRefGoogle ScholarPubMed
Basinger, S.F., Hoffman, R. & Matthes, M. (1976). Photoreceptor shedding is initiated by light in the frog retina. Science 194, 10741076.CrossRefGoogle ScholarPubMed
Basinger, S.F. & Hollyfield, J.G. (1980). Control of rod shedding in the frog rod retina. In Neurochemistry of the Retina, ed. Bazan, N.G. & Lolley, R.N., pp. 8192. Oxford: Pergamon Press.CrossRefGoogle Scholar
Besharse, J.C. (1982). The daily light-dark cycle and rhythimc metabolism in the photoreceptor-pigment epithelial complex. Progress in Retinal Research 1, 81124.CrossRefGoogle Scholar
Besharse, J.C. & Dunis, D.A. (1983). Methoxyindoles and photoreceptor mentabolism: activation of rod shedding. Science 219, 13411343.CrossRefGoogle ScholarPubMed
Besharse, J.C., Iuvone, P.M. & Pierce, M.E. (1988). Regulation of rhythmic photoreceptor metabolism: a role for post-receptoral neurons. Progress in Retinal Research 7, 2161.CrossRefGoogle Scholar
Binkley, S., Hryshchyshyn, M. & Reilly, K. (1979). N-acetyltrans farase activity responds to environmental lighting in the eye as well as in the pineal gland. Nature 281, 479481.CrossRefGoogle ScholarPubMed
Binkley, S., Reilly, K. & Hryshchyshyn, M. (1980).N-acetyltrans ferase in the chick retina, I: Circadian rhythms controlled by environmental lighting are similar to those in the pineal gland. Journal of Comparative Physiology B 139, 103108.CrossRefGoogle Scholar
Cajal, S.R. (1973). The vertebrate retina. In The Vertebrate Retina: Principles of Structure and Function, ed. Rodieck, R.W., pp. 775904. San Francisco: Freeman Press.Google Scholar
Dahl, N.A. & Gordon, W.C. (1986).Rods can be induced to shed photomembranes by a brief pulse of light, phagosomes can form in darkness. Society for Neuroscience Abstracts 12, 632.Google Scholar
Dartnall, H.J.A. (1953). The interpretation of spectral sensitivity curves. British Medical Bulletin 9, 2430.CrossRefGoogle ScholarPubMed
Gordon, W.C. & Dahl, N.A. (1987). Critical light intensities of the various shedding processes in the frog retina. Investigative Ophthalmology and Visual Science 28, 185.Google Scholar
Gordon, W.C. & Ketth, M.E. (1987). D-tubocurarine chloride inhibits rod outer segment shedding in the frog retina. Investigative Ophthalmology and Visual Science 28, 118120.Google ScholarPubMed
Greenberg, L.M. & Besharse, J.C. (1985). Stimulation of photoreceptor disssc shedding and pigment epithelial phagocytosis by glutamate, aspartate, and other amino acids. Journal of Comparative Neurology 239, 361372.CrossRefGoogle Scholar
Hamm, H.E. & Menaker, M. (1980). Retinal rhythms in chicks: circadian variation in melatonin and serotonin N-acetyltransferase activity. Proceedings of the National Academy of Science of the U.S.A. 77, 49985002.CrossRefGoogle ScholarPubMed
LaVall, M.M. (1976). Rod outer segment disc shedding in rat retina: relationship to cyclic lighting. Science 194, 10711073.CrossRefGoogle Scholar
Liebman, P.A. & Entine, G. (1968). Visual pigments of frog and tadpole (Rana pipiens). Vision Research 8, 761775.CrossRefGoogle ScholarPubMed
Nilsson, S.E. (1964). An electron microscopic classification of the retinal receptors of the leopard frog (Rana pipiens). Journal of Ultrastrucre Reserarch 10, 390416.CrossRefGoogle ScholarPubMed
Ogden, T.E., Mascetti, G.G. & Pierantoni, R. (1984). The internal horizontal cell of the frog: analysis of receptor input. Investigative Ophthalmology and Visual Science 25, 13821394.Google ScholarPubMed
Redburn, D.A. & Mitchell, C.K. (1989). Darkness stimulates rapid synthesis and release of melatonin in rat retina. Visual Neuroscience (submitted).CrossRefGoogle Scholar
Young, R.W. (1967). The renewal of photoreceptor outer segments. Journal of Cell Biology 33, 6172.CrossRefGoogle Scholar
Young, R.W. (1978). The daily rhythm of shedding and degradation of rod and cone outer segment membranes in the chick retina. Investigative Ophthalmology and Visual Science 17, 105116.Google ScholarPubMed