scholarly journals Temporal Resolution and Spectral Sensitivity of the Visual System of Three Coastal Shark Species from Different Light Environments

2010 ◽  
Vol 83 (2) ◽  
pp. 299-307 ◽  
Author(s):  
D. Michelle McComb ◽  
Tamara M. Frank ◽  
Robert E. Hueter ◽  
Stephen M. Kajiura
Keyword(s):  
Visual System ◽  
Spectral Sensitivity ◽  
Temporal Resolution ◽  
Shark Species

scholarly journals Daily rhythm of vigilance assessed by temporal resolution of the visual system

2000 ◽  
Vol 40 (25) ◽  
pp. 3467-3473 ◽  
Author(s):  
Martin Lotze ◽  
Bernhard Treutwein ◽  
Till Roenneberg
Keyword(s):  
Visual System ◽  
Temporal Resolution ◽  
Daily Rhythm

scholarly journals OCCHIO E VISIONE: MERAVIGLIA DELLA NATURA O PROGETTO DIFETTOSO?

2020 ◽  
Author(s):  
Pier Giorgio Gobbi
Keyword(s):  
Visual System ◽  
Physical Model ◽  
Temporal Resolution ◽  
Human Visual System ◽  
Dynamic Range ◽  
Evolutionary Design ◽  
Human Eye ◽  
Quantitative Estimates ◽  
Chromatic Aberrations

The behavior of the human visual system exhibits some flaws, including monochromatic and chromatic aberrations, finite dynamic range, limited spatial and temporal resolution. Why did it evolve this way? Can it be improved somehow, for example with the support of technology? The answer is obtained from a neuro-physical model developed by the author, which provides quantitative estimates of the optical and visual performances of the human eye, in agreement with experimental records. The conclusion, based on the principle of utility, is that the evolutionary design of the visual system is perfectly tailored for the primary survival needs of our primitive ancestors in daylight illumination, and it can hardly be improved with the help of human technology.

Visual processing of the zebrafish optic tectum before and after optic nerve damage

2004 ◽  
Vol 21 (2) ◽  
pp. 97-106 ◽  
Author(s):  
ANGELA L. McDOWELL ◽  
LEE J. DIXON ◽  
JENNIFER D. HOUCHINS ◽  
JOSEPH BILOTTA
Keyword(s):  
Optic Nerve ◽  
Visual System ◽  
Spectral Sensitivity ◽  
Visual Processing ◽  
Nerve Damage ◽  
Neural Regeneration ◽  
Nerve Crush ◽  
Sensitivity Functions ◽  
Optic Nerve Damage ◽  
Zebrafish Optic Tectum

Although the zebrafish has become an important model in visual neuroscience, little has been done to examine the processing of its higher visual centers. The purpose of this work was twofold. The first purpose was to examine the physiology of the zebrafish retinotectal system and its relationship to retinal physiology. Spectral sensitivity functions were derived from visually evoked tectal responses and these functions were compared to the functions of electroretinogram (ERG) responses obtained using the same stimulus conditions. The second purpose was to examine the recovery of visual functioning of the tectum following optic nerve damage. The optic nerves of adult zebrafish were damaged (crushed), and tectal visual processing was assessed following damage. The results showed that the spectral sensitivity functions based on the On-responses of the tectum and ERG were qualitatively similar. The functions based on each response type received similar cone contributions including both nonopponent and opponent contributions. However, the spectral sensitivity functions based on the Off-responses of the tectum and ERG differed. The results also showed that the zebrafish visual system is capable of neural regeneration. By 90 days following an optic nerve crush, the spectral sensitivity function based on the tectal On-response was similar to functions obtained from normal zebrafish. Although the tectal Off-response did recover, the spectral sensitivity based on the Off-response was not the same as the function of normal zebrafish. These results support the notion that different levels of the visual system process information differently and that the zebrafish visual system, like those of other lower vertebrates, is capable of functional regeneration.

scholarly journals Spectral sensitivity of the visual system of endemic Baikal amphipods

2020 ◽  
pp. 781-782
Author(s):  
P. Drozdova ◽  
◽  
◽  
A. Saranchina ◽  
M. Timofeyev ◽  
...  
Keyword(s):  
Visual System ◽  
Spectral Sensitivity

scholarly journals The presence of UV wavelengths improves the temporal resolution of the avian visual system

2010 ◽  
Vol 213 (19) ◽  
pp. 3357-3363 ◽  
Author(s):  
D. Rubene ◽  
O. Hastad ◽  
R. Tauson ◽  
H. Wall ◽  
A. Odeen
Keyword(s):  
Visual System ◽  
Temporal Resolution ◽  
Avian Visual System

ERG assessment of zebrafish retinal development

1999 ◽  
Vol 16 (5) ◽  
pp. 881-888 ◽  
Author(s):  
SHANNON SASZIK ◽  
JOSEPH BILOTTA ◽  
CARLA M. GIVIN
Keyword(s):  
Visual System ◽  
Spectral Sensitivity ◽  
Gradual Increase ◽  
Retinal Development ◽  
Visual Stimuli ◽  
Age Groups ◽  
Adult Zebrafish ◽  
Strong Response ◽  
Anatomical Studies ◽  
Sensitivity Functions

Research has shown that adult zebrafish have a complex visual system, with two possible opponent mechanisms. Anatomically, zebrafish retina develops in a sequential manner and is immature at hatching. The purpose of the present study was to assess zebrafish retinal development using the electroretinogram (ERG). ERG responses to visual stimuli were obtained from 4–5, 6–8, 13–15, and 21–24 days postfertilization (dpf) zebrafish. Individual waveforms were assessed and compared across the four age groups. Spectral-sensitivity functions were calculated for the a- and b-wave components of the ERG response. Results showed that the ERG waveforms and spectral-sensitivity functions varied with age. While the 21–24 dpf subjects had an ERG waveform that was similar to that of adults, the younger subjects did not. Although there were modest differences in the a-wave spectral sensitivity, substantial differences were found in the b-wave spectral sensitivities across the ages. There was a consistent strong response to ultraviolet wavelengths, while across the remaining parts of the spectrum, there was a gradual increase in sensitivity with age. Also, the 21–24 dpf subjects appear to have adult-like U- and S-cone functions, but were missing the L-M and the M-S opponent mechanisms found in the adult. These results support the findings of the anatomical studies and demonstrate that the zebrafish is a useful model for examining the development of retinal function.

scholarly journals The evolution of red colour vision is linked to coordinated rhodopsin tuning in lycaenid butterflies

2020 ◽  
Author(s):  
Marjorie A. Liénard ◽  
Gary D. Bernard ◽  
Andrew A. Allen ◽  
Jean-Marc Lassance ◽  
Siliang Song ◽  
...  
Keyword(s):  
Visual System ◽  
Spectral Sensitivity ◽  
Colour Vision ◽  
Bathochromic Shift ◽  
Red Light ◽  
Opsin Gene ◽  
Spectral Energy ◽  
Functional Changes

AbstractColour vision is largely mediated by changes in number, expression, and spectral properties of rhodopsins, but the genetic mechanisms underlying adaptive shifts in spectral sensitivity remain largely unexplored. Using in vivo photochemistry, optophysiology, and in vitro functional assays, we link variation in eye spectral sensitivity at long wavelengths to species-specific absorbance spectra for LW opsins in lycaenid butterflies. In addition to loci specifying an ancestral green-absorbing rhodopsin with maximum spectral sensitivity (λmax) at 520-530 nm in Callophrys sheridanii and Celastrina ladon, we find a novel form of red-shifted LW rhodopsin at λmax = 565-570 nm in Arhopala japonica and Eumaeus atala. Furthermore, we show that Ca. sheridanii and Ce. ladon exhibit a smaller bathochromic shift at BRh2 (480-489 nm), and with the ancestral LW rhodopsin, cannot perceive visible red light beyond 600 nm. In contrast, molecular variation at the LW opsin in A. japonica and E. atala is coordinated with tuning of the blue opsin that also shifts sensitivity to longer wavelengths enabling colour discrimination up to 617 nm. We then use E. atala as a model to examine the interplay between red and blue spectral sensitivity. Owing to blue duplicate expression, the spatial distribution of opsin mRNAs within an ommatidium defines an expanded retinal stochastic mosaic of at least six opsin-based photoreceptor classes. Our mutagenesis in vitro assays with BRh1 (λmax = 435 nm) chimeric blue rhodopsins reveal four main residues contributing to the 65 nm bathochromic shift towards BRh2 (λmax = 500 nm). Adaptations in this four-opsin visual system are relevant for discrimination of conspecific reflectance spectra in E. atala. Together, these findings illustrate how functional changes at multiple rhodopsins contribute to the evolution of a broader spectral sensitivity and adaptation in visual performance.Significance StatementRhodopsins are photosensitive protein molecules that absorb specific wavelengths of incoming light and convey colour information in the visual system. We show that molecular evolution in a green insect opsin gene resulted in a shift in its maximal absorbance peak, enabling some lycaenid butterflies to use spectral energy of longer wavelengths (LW) to discriminate colours in the red spectrum better than relatives bearing ancestral green LW rhodopsins. Lycaenids also evolved a duplicate blue opsin gene, and we illustrate an example where species equipped with red LW rhodopsins shifted their blue sensitivity peak to longer wavelengths due to changes in several blue-tuning residues that have evolved repeatedly in different insect lineages. We demonstrate how changes at multiple vision genes in the insect eye effectively create a coordinated mechanism expanding spectral sensitivity for visually guided behaviours such as selecting host plants and mates.

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