Eyes Wide Shut: the impact of dim-light vision on neural investment in marine teleosts

2018 ◽  
Vol 31 (8) ◽  
pp. 1082-1092 ◽  
Author(s):  
Teresa L. Iglesias ◽  
Alex Dornburg ◽  
Dan L. Warren ◽  
Peter C. Wainwright ◽  
Lars Schmitz ◽  
...  
1963 ◽  
Vol 205 (5) ◽  
pp. 927-940 ◽  
Author(s):  
H. Schiff

The anatomy of the eye of Squilla mantis and the geometrical optics derived from it are briefly described. The shape and size of the electroretinogram (ERG) are dependent on a) position where it is picked up, b) the light intensity, and c) the change of intensity. Single-fiber analysis confirms the results obtained by the anatomy and the ERG of the eye. Frequency of response of a single secondary fiber to intensity changes of light is proportional to the derivate dI/dt ( I = intensity; t = time). The Squilla sees a moving object as the sum of the intensity changes caused by that object, varied in time and space. The eyes have a maximum of sensitivity for light of 535–555 mµ wavelength, and a second maximum in the near ultraviolet light, the latter partly seen as green fluorescence due to an eye pigment. Anatomy, physiology, and the environmental conditions have been combined to explain the vision of this animal, adapted to his life in the blue-violet twilight of the deeper Mediterranean sea.


2016 ◽  
Vol 20 ◽  
pp. 59-66 ◽  
Author(s):  
Stephanie J. Crowley ◽  
Christina Suh ◽  
Thomas A. Molina ◽  
Louis F. Fogg ◽  
Katherine M. Sharkey ◽  
...  

Evolution ◽  
2015 ◽  
Vol 69 (11) ◽  
pp. 2995-3003 ◽  
Author(s):  
Constanze Bickelmann ◽  
James M. Morrow ◽  
Jing Du ◽  
Ryan K. Schott ◽  
Ilke van Hazel ◽  
...  

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Sabrina Asteriti ◽  
Sten Grillner ◽  
Lorenzo Cangiano

Vertebrates acquired dim-light vision when an ancestral cone evolved into the rod photoreceptor at an unknown stage preceding the last common ancestor of extant jawed vertebrates (∼420 million years ago Ma). The jawless lampreys provide a unique opportunity to constrain the timing of this advance, as their line diverged ∼505 Ma and later displayed high-morphological stability. We recorded with patch electrodes the inner segment photovoltages and with suction electrodes the outer segment photocurrents of Lampetra fluviatilis retinal photoreceptors. Several key functional features of jawed vertebrate rods are present in their phylogenetically homologous photoreceptors in lamprey: crucially, the efficient amplification of the effect of single photons, measured by multiple parameters, and the flow of rod signals into cones. These results make convergent evolution in the jawless and jawed vertebrate lines unlikely and indicate an early origin of rods, implying strong selective pressure toward dim-light vision in Cambrian ecosystems.


2018 ◽  
Vol 173 ◽  
pp. 160-178 ◽  
Author(s):  
Anett Karl ◽  
Silke Agte ◽  
Astrid Zayas-Santiago ◽  
Felix N. Makarov ◽  
Yomarie Rivera ◽  
...  

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Mariana G. Figueiro ◽  
Mark S. Rea

Levels of cortisol, a hormone produced by the adrenal gland, follow a daily, 24-hour rhythm with concentrations reaching a minimum in the evening and a peak near rising time. In addition, cortisol levels exhibit a sharp peak in concentration within the first hour after waking; this is known as the cortisol awakening response (CAR). The present study is a secondary analysis of a larger study investigating the impact of short-wavelength(λmax≈470 nm)light on CAR in adolescents who were sleep restricted. The study ran over the course of three overnight sessions, at least one week apart. The experimental sessions differed in terms of the light exposure scenarios experienced during the evening prior to sleeping in the laboratory and during the morning after waking from a 4.5-hour sleep opportunity. Eighteen adolescents aged 12–17 years were exposed to dim light or to 40 lux (0.401 W/m2) of 470-nm peaking light for 80 minutes after awakening. Saliva samples were collected every 20 minutes to assess CAR. Exposure to short-wavelength light in the morning significantly enhanced CAR compared to dim light. Morning exposure to short-wavelength light may be a simple, yet practical way to better prepare adolescents for an active day.


2016 ◽  
Vol 11 (6) ◽  
pp. 756-762
Author(s):  
Veronika Leichtfried ◽  
Friedrich Hanser ◽  
Andrea Griesmacher ◽  
Markus Canazei ◽  
Wolfgang Schobersberger

Context:Demands on concentrative and cognitive performance are high in sport shooting and vary in a circadian pattern, aroused by internal and external stimuli. The most prominent external stimulus is light. Bright light (BL) has been shown to have a certain impact on cognitive and physical performance.Purpose:To evaluate the impact of a single half hour of BL exposure in the morning hours on physical and cognitive performance in 15 sport shooters. In addition, courses of sulfateoxymelatonin (aMT6s), tryptophan (TRP), and kynurenine (KYN) were monitored.Methods:In a crossover design, 15 sport shooters were exposed to 30 min of BL and dim light (DL) in the early-morning hours. Shooting performance, balance, visuomotor performance, and courses of aMT6s, TRP, and KYN were evaluated.Results:Shooting performance was 365.4 (349.7–381.0) and 368.5 (353.9–383.1), identical in both light setups. Numbers of right reactions (sustained attention) and deviations from the horizontal plane (balance-related measure) were higher after BL. TRP concentrations decreased from 77.5 (73.5–81.4) to 66.9 (60.7–67.0) in the DL setup only.Conclusions:The 2 light conditions generated heterogeneous visuomotor and physiological effects in sport shooters. The authors therefore suggest that a single half hour of BL exposure is effective in improving cognitive aspects of performance, but not physical performance. Further research is needed to evaluate BL’s impact on biochemical parameters.


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