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.

scholarly journals Localization of the Violet and Yellow Receptor Cells in the Crayfish Retinula

1973 ◽  
Vol 62 (4) ◽  
pp. 355-374 ◽  
Author(s):  
Eisuke Eguchi ◽  
Talbot H. Waterman ◽  
Jiro Akiyama
Keyword(s):  
Light Adaptation ◽  
Selective Adaptation ◽  
Compound Eyes ◽  
Intracellular Recordings ◽  
Intercellular Coupling ◽  
Retinular Cell ◽  
Particle Distributions ◽  
Wavelength Sensitivity ◽  
Retinal Distribution ◽  
Retinular Cells

Cellular identification of color receptors in crayfish compound eyes has been made by selective adaptation at 450 nm and 570 nm, wavelengths near the λmax's of the two retinular cell classes previously demonstrated. By utilizing earlier evidence, the concentration of lysosome-related bodies (LRB) was used to measure relative light adaptation and thus wavelength sensitivity in 665 retinular cells from six eyes. The observed particle distributions demonstrate the following. Both violet and yellow receptors occur ordinarily in each retinula. Of the seven regular retinular cells two (R3 and R4 using Eguchi's numbering [1965]) have mean sensitivities significantly greater to violet and less to yellow than the other five. The latter apparently comprise "pure" yellow receptors (R1 and R7) and mixed yellow and violet receptors (R2, R5, and R6). Explanations of such ambiguity requiring two visual pigments in single retinular cells or intercellular coupling of adjacent neuroreceptors are apparently precluded by previous evidence. Present data imply alternatively some positional variability in the violet pair's location in individual retinulas. Thus R3 and R4 are predominantly the violet receptors but in some retinulas R2 and R3 or R4 and R5 (or rarely some other cell pairs) may be. The retinal distribution of such variations has yet to be determined. In agreement with intracellular recordings the blue and yellow cells here identified belong to both the vertical and horizontal e-vector sensitive channels.

scholarly journals Spectral and Polarization Sensitivity of the Dipteran Visual System

1972 ◽  
Vol 59 (5) ◽  
pp. 534-558 ◽  
Author(s):  
Gilbert D. McCann ◽  
David W. Arnett
Keyword(s):  
Spectral Sensitivity ◽  
Motion Detection ◽  
Polarization Plane ◽  
Color Discrimination ◽  
Polarization Sensitivity ◽  
Retinular Cell ◽  
First Optic Ganglion ◽  
Optic Ganglion ◽  
The Difference ◽  
Retinular Cells

Spectral and polarization sensitivity measurements were made at several levels (retina, first and third optic ganglion, cervical connective, behavior) of the dipteran visual nervous system. At all levels, it was possible to reveal contributions from the retinular cell subsystem cells 1 to 6 or the retinular cell subsystem cells 7 and 8 or both. Only retinular cells 1 to 6 were directly studied, and all possessed the same spectral sensitivity characterized by two approximately equal sensitivity peaks at 350 and 480 nm. All units of both the sustaining and on-off variety in the first optic ganglion exhibited the same spectral sensitivity as that of retinular cells 1 to 6. It was possible to demonstrate for motion detection and optomotor responses two different spectral sensitivities depending upon the spatial wavelength of the stimulus. For long spatial wavelengths, the spectral sensitivity agreed with retinular cells 1 to 6; however, the spectral sensitivity at short spatial wavelengths was characterized by a single peak at 465 nm reflecting contributions from the (7, 8) subsystem. Although the two subsystems exhibited different spectral sensitivities, the difference was small and no indication of color discrimination mechanisms was observed. Although all retinular cells 1 to 6 exhibited a preferred polarization plane, sustaining and on-off units did not. Likewise, motion detection and optomotor responses were insensitive to the polarization plane for long spatial wavelength stimuli; however, sensitivity to select polarization planes was observed for short spatial wavelengths.

scholarly journals The spectral sensitivity of Drosophila photoreceptors

2020 ◽  
Author(s):  
Camilla R. Sharkey ◽  
Jorge Blanco ◽  
Maya M. Leibowitz ◽  
Daniel Pinto-Benito ◽  
Trevor J. Wardill
Keyword(s):  
Drosophila Melanogaster ◽  
Spectral Sensitivity ◽  
Spectral Range ◽  
Visual Pigment ◽  
Colour Vision ◽  
Neural Processing ◽  
Cross Modulation ◽  
Screening Pigment ◽  
Peak Sensitivity

AbstractDrosophila melanogaster has long been a popular model insect species, due in large part to the availability of genetic tools and is fast becoming the model for insect colour vision. Key to understanding colour reception in Drosophila is in-depth knowledge of spectral inputs and downstream neural processing. While recent studies have sparked renewed interest in colour processing in Drosophila, photoreceptor spectral sensitivity measurements have yet to be carried out in vivo. We have fully characterised the spectral input to the motion and colour vision pathways, and directly measured the effects of spectral modulating factors, screening pigment density and carotenoid-based ocular pigments. All receptor sensitivities had significant shifts in spectral sensitivity compared to previous measurements. Notably, the spectral range of the Rh6 visual pigment is substantially broadened and its peak sensitivity is shifted by 92 nm from 508 to 600 nm. We propose that this deviation can be explained by transmission of long wavelengths through the red screening pigment and by the presence of the blue-absorbing filter in the R7y receptors. Further, we tested direct interactions between photoreceptors and found evidence of interactions between inner and outer receptors, in agreement with previous findings of cross-modulation between receptor outputs in the lamina.

scholarly journals The spectral sensitivity of Drosophila photoreceptors

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Camilla R. Sharkey ◽  
Jorge Blanco ◽  
Maya M. Leibowitz ◽  
Daniel Pinto-Benito ◽  
Trevor J. Wardill
Keyword(s):  
Drosophila Melanogaster ◽  
Spectral Sensitivity ◽  
Spectral Range ◽  
Visual Pigment ◽  
Colour Vision ◽  
Insect Species ◽  
Neural Processing ◽  
Screening Pigment ◽  
Peak Sensitivity

Abstract Drosophila melanogaster has long been a popular model insect species, due in large part to the availability of genetic tools and is fast becoming the model for insect colour vision. Key to understanding colour reception in Drosophila is in-depth knowledge of spectral inputs and downstream neural processing. While recent studies have sparked renewed interest in colour processing in Drosophila, photoreceptor spectral sensitivity measurements have yet to be carried out in vivo. We have fully characterised the spectral input to the motion and colour vision pathways, and directly measured the effects of spectral modulating factors, screening pigment density and carotenoid-based ocular pigments. All receptor sensitivities had significant shifts in spectral sensitivity compared to previous measurements. Notably, the spectral range of the Rh6 visual pigment is substantially broadened and its peak sensitivity is shifted by 92 nm from 508 to 600 nm. We show that this deviation can be explained by transmission of long wavelengths through the red screening pigment and by the presence of the blue-absorbing filter in the R7y receptors. Further, we tested direct interactions between inner and outer photoreceptors using selective recovery of activity in photoreceptor pairs.

Ultraviolet Sensitivity and Spectral Opponency in the Locust

1986 ◽  
Vol 122 (1) ◽  
pp. 193-208
Author(s):  
D. OSORIO
Keyword(s):  
Spectral Sensitivity ◽  
Optic Lobe ◽  
Light Response ◽  
Intracellular Recordings ◽  
Optomotor Response ◽  
Single Population ◽  
Level Flight ◽  
Ultraviolet Sensitivity ◽  
Peak Sensitivity

Intracellular recordings in the medulla of the locust optic lobe reveal units showing u.v. sensitivity and spectral opponency. Previously only a single population of photoreceptors had been recorded in the locust retina, with peak sensitivity from 450–480 nm. Behavioural measurements show that the dorsal light response is elicited only by u.v. light, unlike the optomotor response whose spectral sensitivity is probably attributable to inputs from the green-sensitive cells. The possibility that the cells described may be involved in maintenance of level flight is discussed.

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.

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.

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