Interaction between the serotoninergic and GABAergic systems in frog retina as revealed by electroretinogram

Elka Popova; Petia Kupenova

doi:10.21307/ane-2017-067

Morphological and elemental analysis of isolated incubated frog retina-choroid

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111604 ◽

1984 ◽

Vol 42 ◽

pp. 298-299

Author(s):

B. J. Panessa-Warren ◽

J. B. Warren ◽

H. W. Kraner

Keyword(s):

Elemental Analysis ◽

Pigment Epithelium ◽

Human Retina ◽

Healthy Individuals ◽

Anterior Portion ◽

Pathological Conditions ◽

Frog Retina ◽

Isolated Retina ◽

Vertebrate Eye ◽

Retina Pigment Epithelium

Our previous studies have demonstrated that abnormally high amounts of calcium (Ca) and zinc (Zn) can be accumulated in human retina-choroid under pathological conditions and that barium (Ba), which was not detected in the eyes of healthy individuals, is deposited in the retina pigment epithelium (RPE), and to a lesser extent in the sensory retina and iris. In an attempt to understand how these cations can be accumulated in the vertebrate eye, a morphological and microanalytical study of the uptake and loss of specific cations (K, Ca,Ba,Zn) was undertaken with incubated Rana catesbiana isolated retina and RPE preparations. Large frogs (650-800 gms) were dark adapted, guillotined and their eyes enucleated in deep ruby light. The eyes were hemisected behind the ora serrata and the anterior portion of the eye removed. The eyecup was bisected along the plane of the optic disc and the two segments of retina peeled away from the RPE and incubated.

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REGENERATION OF VISUAL PURPLE IN SOLUTION

The Journal of General Physiology ◽

10.1085/jgp.23.1.21 ◽

1939 ◽

Vol 23 (1) ◽

pp. 21-39 ◽

Cited By ~ 19

Author(s):

Aurin M. Chase ◽

Emil L. Smith

Keyword(s):

Order Process ◽

First Order ◽

Color Changes ◽

Violet Light ◽

Frog Retina ◽

Significant Difference ◽

Kinetics Of ◽

Photosensitive Substance ◽

Subsequent Regeneration

1. Measurements of visual purple regeneration in solution have been made by a procedure which minimized distortion of the results by other color changes so that density changes caused by the regenerating substance alone are obtained. 2. Bleaching a visual purple solution with blue and violet light causes a greater subsequent regeneration than does an equivalent bleaching with light which lacks blue and violet. This is due to a photosensitive substance which has a gradually increasing effective absorption toward the shorter wavelengths. It is uncertain whether this substance is a product of visual purple bleaching or is present in the solution before illumination. 3. The regeneration of visual purple measured at 560 mµ is maximal at about pH 6.7 and decreases markedly at more acid and more alkaline pH's. 4. The absorption spectrum of the regenerating material shows only a concentration change during the course of regeneration, but has a higher absorption at the shorter wavelengths than has visual purple before illumination. 5. Visual purple extractions made at various temperatures show no significant difference in per cent of regeneration. 6. The kinetics of regeneration is usually that of a first order process. Successive regenerations in the same solution have the same velocity constant but form smaller total amounts of regenerated substance. 7. In vivo, the frog retina shows no additional oxygen consumption while visual purple is regenerating.

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