Visual Thresholds and Spectral Sensitivity of Herring Larvae

1968 ◽  
Vol 48 (1) ◽  
pp. 39-53 ◽  
Author(s):  
J. H. S. BLAXTER
Keyword(s):  
Spectral Sensitivity ◽  
Colour Vision ◽  
Action Spectrum ◽  
High Sensitivity ◽  
Visual Response ◽  
Negative Phototaxis ◽  
Positive Phototaxis ◽  
Food Organism ◽  
Action Spectra ◽  
Phototactic Behaviour

1. Herring larvae are characterized by eyes with no rods and no retinomotor responses, though both are present in the adult. 2. By observing the extinction of phototactic behaviour and feeding in herring larvae of different ages held at low intensities of white and coloured light, it was possible to obtain a measure of both threshold light intensities and spectral sensitivity for a pure-cone eye. 3. The phototaxis was positive at higher intensities, the threshold being 100 to 10-1 m.c. Below this threshold a negative phototaxis was observed which disappeared at a much lower threshold, about 10-5 to 10-6 m.c. The threshold for feeding varied with age and the type of food organism, lying between 10-1 and 10-2 m.c. 4. The high sensitivity for negative phototaxis was probably a visual response and not one mediated by a dermal light sense. 5. Spectral sensitivity varied depending on age and behavioural criteria. Using feeding and positive phototaxis the action spectrum was broad and plateau-like with a maximum in the yellow-green and would appear to be similar to other photopic curves. The action spectra for negative phototaxis showed a number of peaks. At hatching three peaks at 450, 520 and 600 mµ might represent three types of cone as postulated by the Young-Helmholtz theory of colour vision.

Phototaxis of adult brine shrimp, Artemia salina

1984 ◽  
Vol 62 (12) ◽  
pp. 2357-2359 ◽  
Author(s):  
David J. Bradley ◽  
Richard B. Forward Jr.
Keyword(s):  
Spectral Sensitivity ◽  
Brine Shrimp ◽  
Artemia Salina ◽  
Threshold Sensitivity ◽  
Behavioral Measure ◽  
Negative Phototaxis ◽  
Light Perception ◽  
Positive Phototaxis ◽  
Low Intensity

Using phototaxis as a behavioral measure of light perception, spectral and intensity sensitivity were determined for adult brine shrimp, Artemia salina. Spectral sensitivity was characterized by a well-defined maximum at 520 nm light, with perhaps a smaller maximum at 400 nm light. Dark-adapted animals showed a strong negative phototaxis at high intensities between 5.0 × 1012 quanta∙m−2∙s−1 and 3.6 × 1016 quanta∙m−2∙s−1 at 520 nm light. Positive phototaxis was greatest at the low intensity of 2.8 × 1012 quanta∙m−2∙s−1. Threshold sensitivity for both positive and negative phototaxis was approximately 2 × 1012 quanta∙m−2∙s−1.

Spectral Sensitivity of Photoreceptors and Colour Vision in the Solitary Bee, Osmia Rufa

1988 ◽  
Vol 136 (1) ◽  
pp. 35-52
Author(s):  
R. MENZEL ◽  
E. STEINMANN ◽  
J. DE SOUZA ◽  
W. BACKHAUS
Keyword(s):  
Spectral Sensitivity ◽  
Colour Vision ◽  
Three Dimensional ◽  
Just Noticeable Difference ◽  
Species Discrimination ◽  
Colour Space ◽  
Absorption Function ◽  
Perceptual Distance ◽  
Line Elements ◽  
Colour Signals

The spectral sensitivity of single photoreceptors of Osmia rufa was determined by a fast voltage-clamp technique. Three receptor types were found whose spectral sensitivity functions followed a rhodopsin-like photopigment absorption function with λmax values at 348nm (ultraviolet receptor), 436nm (blue receptor) and 572nm (green receptor). The λmax of the green receptor in Osmia rufa is shifted to much longer wavelengths compared with other insect species. Discrimination of colour signals was tested after training a bee at the entrance to its nest. The colour signals were filter discs (70 mm in diameter) with a hole (10 mm in diameter) in the centre and the bees quickly learned to use the coloured disc as a marker of the nest entrance. Tests were dual forced-choice tests with two coloured discs closely positioned next to each other. 94 different tests were each repeated 5–15 times and were performed after training to 12 different colour signals. A photoreceptor model was used to calculate the loci of the colour signals in a three-dimensional colour space and in a chromaticity diagram. The perceptual distance between the colour loci was calculated as line elements (minimum number of just noticeable difference, jnd-steps), which were based on the noiseproperties of the photoreceptors. The discrimination determined by the behavioural tests correlated very well with the jnd-steps. The correlation was better for the line elements in the colour plane than in the colour space. Osmia rufa was compared with the honeybee Apis mellifera and the stingless bee Melipona quadrifasciata. There is no difference in colour selection between Osmia and Apis, whereas Melipona discriminates less well in the violet-blue region. The model calculation was used to compare the chromaticity diagrams and the spectral discrimination functions of the three species. It is concluded that the receptor model used in this study predicts the discrimination behaviour of the three bee species very well. Therefore, comparative studies on colour vision in flowervisiting insects may be based on spectral measurements of the photoreceptors, and in many cases this reduces the extent of laborious behavioural studies.

Feeding behavior in the nocturnal moth Manduca sexta is mediated mainly by blue receptors, but where are they located in the retina?

1995 ◽  
Vol 198 (9) ◽  
pp. 1909-1917 ◽  
Author(s):  
D Cutler ◽  
R Bennett ◽  
R Stevenson ◽  
R White
Keyword(s):  
Manduca Sexta ◽  
Spectral Sensitivity ◽  
Compound Eye ◽  
Action Spectrum ◽  
Minor Role ◽  
Feeding Response ◽  
Small Areas ◽  
Nectar Feeding ◽  
A Minor ◽  
Two Peaks

The spectral sensitivity of nectar feeding by adults of the tobacco hawkmoth Manduca sexta was measured in free-choice experiments. The action spectrum displayed a narrow peak at 450 nm and a low secondary maximum at 560 nm. Thus, the feeding response is mediated primarily by blue-sensitive receptors containing the Manduca sexta photopigment P450, while green-sensitive receptors containing P520 play a minor role. A minimum at 500 nm separating the two peaks suggests mutual inhibition between green and blue receptors or negative interaction more proximally in the visual system. The action spectrum drops off abruptly at 400 nm, in accordance with an earlier finding that ultraviolet wavelengths, discerned by receptors containing P357, obstruct the feeding response. The spectral sensitivity of the Manduca sexta compound eye, determined by electroretinogram recordings, and earlier visual pigment measurements indicate that approximately 75 % of the receptors are green-sensitive, with the remainder divided between blue- and ultraviolet-sensitive cells. The distribution of receptor types in small areas of the retina was measured by their ultrastructural response to light. Green and ultraviolet receptors were found, but not the blue receptors that dominate the feeding response. Possibly they are concentrated in a particular region of the retina that has not yet been found.

scholarly journals Colorimetric Nanoplasmonics to Spot Hyperglycemia From Saliva

2020 ◽  
Vol 8 ◽  
Author(s):  
Paolo Donati ◽  
Tania Pomili ◽  
Luca Boselli ◽  
Pier P. Pompa
Keyword(s):  
Large Scale ◽  
Point Of Care ◽  
High Sensitivity ◽  
Diabetic Patients ◽  
Visual Response ◽  
Colorimetric Sensing ◽  
Chronic Patients ◽  
Self Monitoring ◽  
Sensing Platform ◽  
Signal Color

Early diagnostics and point-of-care (POC) devices can save people’s lives or drastically improve their quality. In particular, millions of diabetic patients worldwide benefit from POC devices for frequent self-monitoring of blood glucose. Yet, this still involves invasive sampling processes, which are quite discomforting for frequent measurements, or implantable devices dedicated to selected chronic patients, thus precluding large-scale monitoring of the globally increasing diabetic disorders. Here, we report a non-invasive colorimetric sensing platform to identify hyperglycemia from saliva. We designed plasmonic multibranched gold nanostructures, able to rapidly change their shape and color (naked-eye detection) in the presence of hyperglycemic conditions. This “reshaping approach” provides a fast visual response and high sensitivity, overcoming common detection issues related to signal (color intensity) losses and bio-matrix interferences. Notably, optimal performances of the assay were achieved in real biological samples, where the biomolecular environment was found to play a key role. Finally, we developed a dipstick prototype as a rapid home-testing kit.

Nonlinear integration of multispectral information: Human colour vision analogues to sensory integration in rattlesnake

2012 ◽  
Vol 25 (0) ◽  
pp. 179
Author(s):  
Vincent A. Billock ◽  
Brian H. Tsou
Keyword(s):  
Spectral Sensitivity ◽  
Information Integration ◽  
Sensory Integration ◽  
Colour Vision ◽  
Neural Model ◽  
Neural Firing ◽  
Visual Responses ◽  
Neural Synchronization ◽  
Synchronization Mechanism ◽  
Integration Problems

Information integration occurs at every sensory scale and although distinctions are made for integration between and within senses, integration at intermediate scales may exploit familiar mechanisms. Here, we explore this idea by applying a sensory integration mechanism to some poorly understood multispectral integration problems in human colour vision. Billock and Tsou (IMRF, 2011) used a binding-like neural synchronization mechanism to model intensity-dependent (inverse) enhancement of visual responses by auditory stimulation in cat. The same model also applies to mutual enhancement of visual and infrared responses in rattlesnake, suggesting that a similar mechanism could model integration of spectral information in human colour vision. For example, chromatic brightness is thought to be a vector-like nonlinear combination of luminance and chromatic channels; its neural correlate is unknown. We model its spectral sensitivity by pairwise excitatory synchronization between luminance (broadband) neurons and cortically rectified L+M- and S+M-L- LGN neurons. Similarly, the yellow lobe of the yellow-blue opponent channel is known to be a nonlinearly enhanced combination of long- and medium-wavelength-sensitive inputs, but no sensible neural model for this interaction has been advanced. We model the spectral sensitivity of ‘yellowness’ using excitatory synchronization between cortically rectified L+M+S- and M+L- LGN units. The inputs for both simulations were macaque neural firing rate data (DeValois et al., 1966). Fascinatingly, in both cases, multispectral integration in human colour vision was well modeled using the rattlesnake/cat neural synchronization equations without any use of fitting parameters. This is the first application of sensory integration concepts to human colour vision transformations.

scholarly journals Difference in the action spectra for UVR8 monomerisation and HY5 transcript accumulation in Arabidopsis

2018 ◽  
Vol 17 (8) ◽  
pp. 1108-1117 ◽  
Author(s):  
L. Aranzazú Díaz-Ramos ◽  
Andrew O'Hara ◽  
Selvaraju Kanagarajan ◽  
Daniel Farkas ◽  
Åke Strid ◽  
...  
Keyword(s):  
Action Spectrum ◽  
Transcript Accumulation ◽  
Action Spectra

The action spectrum for monomerisation of the plant UV-B photoreceptor UVR8 peaks at a shorter wavelength than that for HY5 transcript accumulation, mediated by UVR8, in the same tissue.

scholarly journals Photoreceptors and diurnal variation in spectral sensitivity in the fiddler crab Gelasimus dampieri

2020 ◽  
Vol 223 (23) ◽  
pp. jeb230979
Author(s):  
Anna-Lee Jessop ◽  
Yuri Ogawa ◽  
Zahra M. Bagheri ◽  
Julian C. Partridge ◽  
Jan M. Hemmi
Keyword(s):  
Spectral Sensitivity ◽  
Colour Vision ◽  
Fiddler Crab ◽  
Selective Adaptation ◽  
Diurnal Changes ◽  
Intracellular Recordings ◽  
Retinular Cell ◽  
Minimum Requirement ◽  
Peak Sensitivity ◽  
Retinular Cells

ABSTRACTColour signals, and the ability to detect them, are important for many animals and can be vital to their survival and fitness. Fiddler crabs use colour information to detect and recognise conspecifics, but their colour vision capabilities remain unclear. Many studies have attempted to measure their spectral sensitivity and identify contributing retinular cells, but the existing evidence is inconclusive. We used electroretinogram (ERG) measurements and intracellular recordings from retinular cells to estimate the spectral sensitivity of Gelasimus dampieri and to track diurnal changes in spectral sensitivity. G. dampieri has a broad spectral sensitivity and is most sensitive to wavelengths between 420 and 460 nm. Selective adaptation experiments uncovered an ultraviolet (UV) retinular cell with a peak sensitivity shorter than 360 nm. The species’ spectral sensitivity above 400 nm is too broad to be fitted by a single visual pigment and using optical modelling, we provide evidence that at least two medium-wavelength sensitive (MWS) visual pigments are contained within a second blue-green sensitive retinular cell. We also found a ∼25 nm diurnal shift in spectral sensitivity towards longer wavelengths in the evening in both ERG and intracellular recordings. Whether the shift is caused by screening pigment migration or changes in opsin expression remains unclear, but the observation shows the diel dynamism of colour vision in this species. Together, these findings support the notion that G. dampieri possesses the minimum requirement for colour vision, with UV and blue/green receptors, and help to explain some of the inconsistent results of previous research.

Spectral sensitivity of the electroretinogram b-wave in dark-adapted goldfish

1988 ◽  
Vol 1 (2) ◽  
pp. 159-168 ◽  
Author(s):  
Jonathan D. Nussdorf ◽  
Maureen K. Powers
Keyword(s):  
Absorption Spectrum ◽  
Spectral Sensitivity ◽  
Neural Activity ◽  
Dark Adaptation ◽  
Carassius Auratus ◽  
Action Spectrum ◽  
Absolute Threshold ◽  
Selective Loss

AbstractThe action spectrum of the ERG b-wave was measured under dark-adapted conditions in intact goldfish (Carassius auratus). It is substantially broader than the absorption spectrum of goldfish rod porphyropsin. Neither prolonged dark adaptation nor removal of possible efferent neural activity affected its shape. Moreover, a 682-nm background did not produce a selective loss of sensitivity to long wavelengths. The results imply that the spectral sensitivity of the b-wave in dark-adapted goldfish reflects the influence of at least two photoreceptor types which act as a single univariant mechanism near absolute threshold.

Effect of chlorpromazine on phototactic behavior in Chlamydomonas

1980 ◽  
Vol 26 (2) ◽  
pp. 265-267 ◽  
Author(s):  
Rona Hirschberg ◽  
William Hutchinson
Keyword(s):  
Control System ◽  
Light Intensity ◽  
Antipsychotic Drug ◽  
Green Alga ◽  
Negative Phototaxis ◽  
Low Light ◽  
Positive Phototaxis ◽  
Phototactic Behavior ◽  
Common Control

Chlorpromazine, an antipsychotic drug, causes a light intensity dependent reversal of phototaxis in the green alga Chlamydomonas reinhardi. At moderate light intensity, drug-treated cells swim away from the light (negative phototaxis) while untreated cells swim toward it (positive phototaxis). At low light, both treated and untreated cells exhibit normal positive phototactic responses. It appears that light and chlorpromazine may affect a common control system for phototaxis.

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