Warning: Undefined array key "mm" in /www/wwwroot/www.ai-bt.com/si.php on line 10 Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in /www/wwwroot/www.ai-bt.com/si.php on line 10 The attenuation of rod signals by bleachings.

Literature DB >> 5499030

The attenuation of rod signals by bleachings.

Abstract

1. Contrast flash technique allows the rod threshold to be measured even when it lies far above the cone threshold. In this way the rod dark adaptation curve after rhodopsin bleaching can be measured over 6 log units.2. By retinal densitometry the regeneration of rhodopsin can be measured in the same subject. It is found that the log threshold is raised 1.2 units for each 10% of rhodopsin in the bleached state.3. We have tried to discover whether bleaching raises the threshold by desensitizing the rods, or (like backgrounds) by attenuating their signals. Neither suggestion satisfies all conditions.4. All are satisfied by [Formula: see text], where N is the size of rod signal, constant for threshold; theta, theta(D) are steady backgrounds of light and receptor noise; varphi is the threshold flash with sigma a constant of about 2.5 log td sec; B the fraction of pigment in the bleached state.

Entities: Gene

Mesh：
Dark Adaptation

Year: 1970 PMID： 5499030 PMCID： PMC1348717 DOI： 10.1113/jphysiol.1970.sp009072

Source DB: PubMed Journal: J Physiol ISSN： 0022-3751 Impact factor: 5.182

12 in total

Review 1. Mechanistic studies of ABCR, the ABC transporter in photoreceptor outer segments responsible for autosomal recessive Stargardt disease.

Authors: H Sun; J Nathans
Journal: J Bioenerg Biomembr Date: 2001-12 Impact factor: 2.945

The attenuation of rod signals by bleachings.

1. THE ROLE OF AFTERIMAGES IN DARK ADAPTATION.

2. ROD-CONE INDEPENDENCE IN THE AFTER-FLASH EFFECT.

3. The effect upon the rod threshold of bleaching neighbouring rods.

4. Dark-adaptation and the regeneration of rhodopsin.

5. The difference spectrum and the photosensitivity of rhodopsin in the living human eye.

6. The nature of rise in threshold produced by contrast-flashes.

7. The size of rod signals.

8. The rod increment threshold during dark adaptation in normal and rod monochromat.

9. Dark-adaptation: a new hypothesis.

10. The attenuation of rod signals by backgrounds.

Review 1. Mechanistic studies of ABCR, the ABC transporter in photoreceptor outer segments responsible for autosomal recessive Stargardt disease.

2. On the analysis of nerve signals deduced from metacontrast experiments with human observers.

3. The dark adaptation curve of rods measured by their after-image.

4. On the retinal basis of visual adaptation.

5. Signals from cones.

6. The saturation of monochromatic lights obliquely incident on the retina.

7. The influence of rod light and dark adaptation upon rod-cone interaction.

8. An analysis of rod outer segment adaptation based on a simple equivalent circuit.

9. Effects of bleaching and backgrounds on the flash response of the cone system.

10. Rhodopsin bleaching signals in essential night blindness.