Spatial summation and visual adaptation in the inner part of the frog retina

2009 ◽  
Vol 67 (2) ◽  
pp. 131-136 ◽  
Author(s):  
Ingrid Hahn ◽  
Lillemor Wachtmeister
Keyword(s):  
Spatial Summation ◽  
Visual Adaptation ◽  
Frog Retina

Morphological and elemental analysis of isolated incubated frog retina-choroid

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.

Visual Adaptation and Its Neural Mechanisms

2015 ◽  
Vol 23 (7) ◽  
pp. 1196 ◽  
Author(s):  
Fen ZHANG ◽  
Suiping WANG ◽  
Juanhua YANG ◽  
Gangyi FENG
Keyword(s):  
Neural Mechanisms ◽  
Visual Adaptation

Photoelectric Visual Adaptation Based on 0D‐CsPbBr 3 ‐Quantum‐Dots/2D‐MoS 2 Mixed‐Dimensional Heterojunction Transistor

2021 ◽  
Vol 31 (14) ◽  
pp. 2010655
Author(s):  
Dingdong Xie ◽  
Liubo Wei ◽  
Min Xie ◽  
Leyong Jiang ◽  
Junliang Yang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Visual Adaptation ◽  
Heterojunction Transistor

scholarly journals Contrast integration over area is extensive: A three-stage model of spatial summation

2011 ◽  
Vol 11 (14) ◽  
pp. 14 ◽  
Author(s):  
Daniel H. Baker ◽  
Tim S. Meese
Keyword(s):  
Spatial Summation ◽  
Stage Model

Visual adaptation: A case of nonlinear summation

1972 ◽  
Vol 12 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Raymon M. Glantz
Keyword(s):  
Visual Adaptation

scholarly journals REGENERATION OF VISUAL PURPLE IN SOLUTION

1939 ◽  
Vol 23 (1) ◽  
pp. 21-39 ◽  
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.

Attentional states and the degree of visual adaptation to gratings

2004 ◽  
Vol 17 (5-6) ◽  
pp. 849-860 ◽  
Author(s):  
Yariv Festman ◽  
Merav Ahissar
Keyword(s):  
Visual Adaptation
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