Effects of calcium ions on L-type horizontal cells in the isolated turtle retina

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Publication Type Journal Article
School or College School of Medicine
Department Pathology; Ophthalmology; Surgery; Bioengineering; Physiology
Creator Normann, Richard A.; Chandler, John P.
Other Author Perlman, Ido; Lipetz, Leo E.
Title Effects of calcium ions on L-type horizontal cells in the isolated turtle retina
Date 1990
Description A technique by which the retina can be isolated from the turtle eye is described. Scanning electron microscopy revealed morphological variability between preparations and also between regions of the same one. Large areas were often totally free of any pigment epithelial cells, yet contained a high proportion of photoreceptors with complete outer segments. However, adjacent regions may contain photoreceptors without outer segments or with fragmented ones. The physiological properties of the horizontal cells also demonstrated large variability between different preparations. In all cases, lowering calcium concentration from 2 mM to 0.1-0.5 mM depolarized the horizontal cells and augmented the amplitude of the maximum photoresponses. However, these effects were accompanied by changes in the photoresponse kinetics and by a reduction in the horizontal cell sensitivity to light. Moreover, prolonged exposure to low calcium induced permanent damage to the retina as was indicated by the reduction in the response amplitude after superfusion with 2 mM calcium solution had been resumed. The toxic effects of low calcium were most apparent when superfusion with 0.1-1.0 microM calcium concentration was performed. These solutions induced complex time-dependent effects on the resting potential of horizontal cells and on the amplitude and kinetics of the photoresponses. We conclude from these observations that the normal concentration of extracellular calcium in the turtle retina is in the 2 mM range.
Type Text
Publisher Cambridge University Press
Volume 4
Issue 1
First Page 53
Last Page 62
Subject Retina; Calcium; Horizontal Cell; Turtle
Subject MESH Calcium; Photoreceptors; Retina; Cell Separation
Language eng
Bibliographic Citation Perlman I, Normann RA, Chandler JP, Lipetz LE. (1990). Effects of calcium ions on L-type horizontal cells in the isolated turtle retina. Vis Neurosci, 4(1), 53-62
Rights Management © Cambridge University Press
Format Medium application/pdf
Identifier ir-main,12742
ARK ark:/87278/s6ms4b7t
Setname ir_uspace
Date Created 2012-06-13
Date Modified 2021-05-06
ID 705686
Reference URL https://collections.lib.utah.edu/ark:/87278/s6ms4b7t
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