The effect of light adaptation on pupillary diameter

1960 ◽  
Author(s):  
G. Hakerem ◽  
S. Sutton ◽  
J. Zubin
Keyword(s):  
Light Adaptation ◽  
Pupillary Diameter ◽  
Effect Of Light

Effect of light-adaptation on the binding of 48-kDa protein (S-antigen) to photoreceptor cell membranes

1987 ◽  
Vol 6 (4) ◽  
pp. 607-610 ◽  
Author(s):  
R. M. Broekhuyse ◽  
A. P. M. Janssen ◽  
E. F. J. Tolhuizen
Keyword(s):  
Cell Membranes ◽  
Light Adaptation ◽  
Photoreceptor Cell ◽  
Protein S ◽  
Effect Of Light

scholarly journals Light Adaptation of Discrete Waves in the Limulus Photoreceptor

1972 ◽  
Vol 60 (1) ◽  
pp. 86-101 ◽  
Author(s):  
Richard Srebro ◽  
Mahmood Behbehani
Keyword(s):  
Time Course ◽  
Light Adaptation ◽  
Limulus Photoreceptor ◽  
Average Size ◽  
Effect Of Light

Light adaptation affects discrete waves in two ways. It reduces their average size and decreases the probability that a photon incident at the cornea causes a discrete wave. There is no effect of light adaptation on the latency of discrete waves, or on their time-course.

Localization of heme oxygenase in rat retina: effect of light adaptation

1996 ◽  
Vol 205 (1) ◽  
pp. 13-16 ◽  
Author(s):  
Robert N. Nishimura ◽  
Barney E. Dwyer ◽  
Shi-Yi Lu
Keyword(s):  
Heme Oxygenase ◽  
Light Adaptation ◽  
Rat Retina ◽  
Effect Of Light

scholarly journals Kinetics of Turn-offs of Frog Rod Phototransduction Cascade

2008 ◽  
Vol 132 (5) ◽  
pp. 587-604 ◽  
Author(s):  
Luba A. Astakhova ◽  
Michael L. Firsov ◽  
Victor I. Govardovskii
Keyword(s):  
Time Constant ◽  
Dark Current ◽  
Main Part ◽  
Time Course ◽  
Light Adaptation ◽  
Key Factors ◽  
Time Courses ◽  
Kinetics Of ◽  
Phototransduction Cascade ◽  
Effect Of Light

The time course of the light-induced activity of phototrandsuction effector enzyme cGMP-phosphodiesterase (PDE) is shaped by kinetics of rhodopsin and transducin shut-offs. The two processes are among the key factors that set the speed and sensitivity of the photoresponse and whose regulation contributes to light adaptation. The aim of this study was to determine time courses of flash-induced PDE activity in frog rods that were dark adapted or subjected to nonsaturating steady background illumination. PDE activity was computed from the responses recorded from solitary rods with the suction pipette technique in Ca2+-clamping solution. A flash applied in the dark-adapted state elicits a wave of PDE activity whose rising and decaying phases have characteristic times near 0.5 and 2 seconds, respectively. Nonsaturating steady background shortens both phases roughly to the same extent. The acceleration may exceed fivefold at the backgrounds that suppress ≈70% of the dark current. The time constant of the process that controls the recovery from super-saturating flashes (so-called dominant time constant) is adaptation independent and, hence, cannot be attributed to either of the processes that shape the main part of the PDE wave. We hypothesize that the dominant time constant in frog rods characterizes arrestin binding to rhodopsin partially inactivated by phosphorylation. A mathematical model of the cascade that considers two-stage rhodopsin quenching and transducin inactivation can mimic experimental PDE activity quite well. The effect of light adaptation on the PDE kinetics can be reproduced in the model by concomitant acceleration on both rhodopsin phosphorylation and transducin turn-off, but not by accelerated arrestin binding. This suggests that not only rhodopsin but also transducin shut-off is under adaptation control.

scholarly journals An Endogenous Crepuscular Rhythm Of Rainbow Trout (Salmo Gairdneri) Photomechanical Movements

1982 ◽  
Vol 96 (1) ◽  
pp. 377-388 ◽  
Author(s):  
R. H. Douglas
Keyword(s):  
Rainbow Trout ◽  
Direct Effect ◽  
Light Adaptation ◽  
Endogenous Rhythm ◽  
Salmo Gairdneri ◽  
Natural Light ◽  
Behavioural Pattern ◽  
Two Peaks ◽  
Endogenous Component ◽  
Effect Of Light

1. The position of the epithelial pigment and cones in the retina of Salmo gairdneri was determined during extended periods of darkness in fish entrained to both artificial and natural light/dark cycles. 2. An endogenous rhythm of such photomechanical movements, unique among species so far examined, was observed in both groups of fish, with two peaks of light adaptation coincident with dawn and dusk. 3. It is suggested that such an apparently non-adaptive physiological rhythm is related to the behavioural pattern of trout and reveals a basic crepuscular organisation. 4. No endogenous rhythm was observed in continual light. 5. These results suggest that control of photomechanical changes in rainbow trout has two components: an endogenous component, that causes the bimodal pattern in maintained darkness, and a direct effect of light, that maintains light adaptation throughout a normal day. Note:

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