scholarly journals Electroretinogram Characteristics and the Spectral Mechanisms of the Median Ocellus and the Lateral Eye in Limulus polyphemus

1967 ◽  
Vol 50 (9) ◽  
pp. 2267-2287 ◽  
Author(s):  
Robert M. Chapman ◽  
Abner B. Lall
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Light Adaptation ◽  
Compound Eye ◽  
State Level ◽  
Chromatic Adaptation ◽  
Absorption Bands ◽  
Energy Functions ◽  
Lateral Eye ◽  
Median Ocellus

Electrical responses (ERG) to light flashes of various wavelengths and energies were obtained from the dorsal median ocellus and lateral compound eye of Limulus under dark and chromatic light adaptation. Spectral mechanisms were studied by analyzing (a) response waveforms, e.g. response area, rise, and fall times as functions of amplitude, (b) slopes of amplitude-energy functions, and (c) spectral sensitivity functions obtained by the criterion amplitude method. The data for a single spectral mechanism in the lateral eye are (a) response waveforms independent of wavelength, (b) same slope for response-energy functions at all wavelengths, (c) a spectral sensitivity function with a single maximum near 520 mµ, and (d) spectral sensitivity invariance in chromatic adaptation experiments. The data for two spectral mechanisms in the median ocellus are (a) two waveform characteristics depending on wavelength, (b) slopes of response-energy functions steeper for short than for long wavelengths, (c) two spectral sensitivity peaks (360 and 530–535 mµ) when dark-adapted, and (d) selective depression of either spectral sensitivity peak by appropriate chromatic adaptation. The ocellus is 200–320 times more sensitive to UV than to visible light. Both UV and green spectral sensitivity curves agree with Dartnall's nomogram. The hypothesis is favored that the ocellus contains two visual pigments each in a different type of receptor, rather than (a) various absorption bands of a single visual pigment, (b) single visual pigment and a chromatic mask, or (c) fluorescence. With long duration light stimuli a steady-state level followed the transient peak in the ERG from both types of eyes.

scholarly journals The Spectral Sensitivities of Single Cells in the Median Ocellus of Limulus

1969 ◽  
Vol 54 (5) ◽  
pp. 636-649 ◽  
Author(s):  
John Nolte ◽  
Joel E. Brown
Keyword(s):  
Visible Light ◽  
Spectral Sensitivity ◽  
Uv Light ◽  
Single Cells ◽  
Chromatic Adaptation ◽  
Sensitivity Curve ◽  
Receptor Cells ◽  
Intracellular Microelectrodes ◽  
Median Ocellus ◽  
Spectral Sensitivity Curve

The spectral sensitivities of single Limulus median ocellus photoreceptors have been determined from records of receptor potentials obtained using intracellular microelectrodes. One class of receptors, called UV cells (ultraviolet cells), depolarizes to near-UV light and is maximally sensitive at 360 nm; a Dartnall template fits the spectral sensitivity curve. A second class of receptors, called visible cells, depolarizes to visible light; the spectral sensitivity curve is fit by a Dartnall template with λmax at 530 nm. Dark-adapted UV cells are about 2 log units more sensitive than dark-adapted visible cells. UV cells respond with a small hyperpolarization to visible light and the spectral sensitivity curve for this hyperpolarization peaks at 525–550 nm. Visible cells respond with a small hyperpolarization to UV light, and the spectral sensitivity curve for this response peaks at 350–375 nm. Rarely, a double-peaked (360 and 530 nm) spectral sensitivity curve is obtained; two photopigments are involved, as revealed by chromatic adaptation experiments. Thus there may be a small third class of receptor cells containing two photopigments.

scholarly journals Single and Multiple Visual Systems in Arthropods

1968 ◽  
Vol 51 (2) ◽  
pp. 125-156 ◽  
Author(s):  
George Wald
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Light Adaptation ◽  
Procambarus Clarkii ◽  
Color Discrimination ◽  
Visual Pigments ◽  
Green Crab ◽  
Spider Crab ◽  
Color Adaptation ◽  
Visual Systems

Extraction of two visual pigments from crayfish eyes prompted an electrophysiological examination of the role of visual pigments in the compound eyes of six arthropods. The intact animals were used; in crayfishes isolated eyestalks also. Thresholds were measured in terms of the absolute or relative numbers of photons per flash at various wavelengths needed to evoke a constant amplitude of electroretinogram, usually 50 µv. Two species of crayfish, as well as the green crab, possess blue- and red-sensitive receptors apparently arranged for color discrimination. In the northern crayfish, Orconectes virilis, the spectral sensitivity of the dark-adapted eye is maximal at about 550 mµ, and on adaptation to bright red or blue lights breaks into two functions with λmax respectively at about 435 and 565 mµ, apparently emanating from different receptors. The swamp crayfish, Procambarus clarkii, displays a maximum sensitivity when dark-adapted at about 570 mµ, that breaks on color adaptation into blue- and red-sensitive functions with λmax about 450 and 575 mµ, again involving different receptors. Similarly the green crab, Carcinides maenas, presents a dark-adapted sensitivity maximal at about 510 mµ that divides on color adaptation into sensitivity curves maximal near 425 and 565 mµ. Each of these organisms thus possesses an apparatus adequate for at least two-color vision, resembling that of human green-blinds (deuteranopes). The visual pigments of the red-sensitive systems have been extracted from the crayfish eyes. The horse-shoe crab, Limulus, and the lobster each possesses a single visual system, with λmax respectively at 520 and 525 mµ. Each of these is invariant with color adaptation. In each case the visual pigment had already been identified in extracts. The spider crab, Libinia emarginata, presents another variation. It possesses two visual systems apparently differentiated, not for color discrimination but for use in dim and bright light, like vertebrate rods and cones. The spectral sensitivity of the dark-adapted eye is maximal at about 490 mµ and on light adaptation, whether to blue, red, or white light, is displaced toward shorter wavelengths in what is essentially a reverse Purkinje shift. In all these animals dark adaptation appears to involve two phases: a rapid, hyperbolic fall of log threshold associated probably with visual pigment regeneration, followed by a slow, almost linear fall of log threshold that may be associated with pigment migration.

Visions of vision: Studies of the horseshoe crab compound eye

1992 ◽  
Vol 50 (1) ◽  
pp. 488-489
Author(s):  
Steven C. Chamberlain
Keyword(s):  
Horseshoe Crab ◽  
Light Adaptation ◽  
Compound Eye ◽  
Visually Guided ◽  
Morphological Process ◽  
Morphological Studies ◽  
Visual Processes ◽  
Lateral Eye ◽  
The Brain

The lateral eye of the horseshoe crab, Limulus polyphemus, is an important model system for studies of visual processes such as phototransduction, lateral inhibition, and light adaptation. It has also been the system of choice for pioneering studies of the role of circadian efferent input from the brain to the eye. For example, light and efferent input interact in controlling the daily shedding of photosensitive membrane and photomechanical movements. Most recently, modeling efforts have begun to relate anatomy, physiology and visually guided behavior using parallel computing. My laboratory has pursued collaborative morphological studies of the compound eye for the past 15 years. Some of this research has been correlated structure/function studies; the rest has been studies of basic morphology and morphological process.

scholarly journals The Spectral Sensitivity of Crayfish and Lobster Vision

1961 ◽  
Vol 44 (6) ◽  
pp. 1089-1102 ◽  
Author(s):  
Donald Kennedy ◽  
Merle S. Bruno
Keyword(s):  
Fresh Water ◽  
Spectral Sensitivity ◽  
Light Adaptation ◽  
Compound Eye ◽  
Monochromatic Light ◽  
Sensitivity Function ◽  
Visual Sensitivity ◽  
Long Wavelength ◽  
Cone Pigments ◽  
Sensitivity Data

(1) The spectral sensitivity function for the compound eye of the crayfish has been determined by recording the retinal action potentials elicited by monochromatic stimuli. Its peak lies at approximately 570 mµ. (2) Similar measurements made on lobster eyes yield functions with maxima in the region of 520 to 525 mµ, which agree well with the absorption spectrum of lobster rhodopsin if minor allowances are made for distortion by known screening pigments. (3) The crayfish sensitivity function, since it is unaffected by selective monochromatic light adaptation, must be determined by a single photosensitive pigment. The absorption maximum of this pigment may be inferred with reasonable accuracy from the sensitivity data. (4) The visual pigment of the crayfish thus has its maximum absorption displaced by 50 to 60 mµ towards the red end of the spectrum from that of the lobster and other marine crustacea. This shift parallels that found in both rod and cone pigments between fresh water and marine vertebrates. In the crayfish, however, an altered protein is responsible for the shift and not a new carotenoid chromophore as in the vertebrates. (5) The existence of this situation in a new group of animals (with photoreceptors which have been evolved independently from those of vertebrates) strengthens the view that there may be strong selection for long wavelength visual sensitivity in fresh water.

Spectral sensitivity, visual pigments and screening pigments in two life history stages of the ontogenetic migrator Gnathophausia ingens

2009 ◽  
Vol 89 (1) ◽  
pp. 119-129 ◽  
Author(s):  
Tamara M. Frank ◽  
Megan Porter ◽  
Thomas W. Cronin
Keyword(s):  
Life History ◽  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Chromatic Adaptation ◽  
Age Classes ◽  
Long Wavelength ◽  
Life History Stages ◽  
Near Ultraviolet ◽  
Maximal Sensitivity ◽  
Absorbance Spectra

Spectral sensitivity, visual pigment absorbance spectra and visual pigment opsin sequences were examined in younger shallow-living and older deep-living instars of the ontogenetically migrating lophogastrid Gnathophausia ingens. Spectral sensitivity measurements from dark adapted eyes and microspectrophotometric measurements of the rhabdom indicate maximal sensitivity for long wavelength (495–502 nm) light in both life history stages, but the younger instars are significantly more sensitive to near-ultraviolet light than the adults. Both life history stages express the same two opsins, indicating that there is no ontogenetic change in visual pigment complement between life history stages. Chromatic adaptation shifted the spectral sensitivity maximum to significantly longer wavelengths in both age-classes, but a distinct secondary short wavelength peak is visible only in the younger instars. These shifts appear to be due to the presence of migrating screening pigments, which are probably vestigial in the deep-living adults. Anomalies in the response waveforms under chromatic adaptation also apparently result from filtering by screening pigments, but via an unknown mechanism.

Variation in opsin transcript expression explains intraretinal differences in spectral sensitivity of the northern anchovy

2018 ◽  
Vol 35 ◽  
Author(s):  
ILARIA SAVELLI ◽  
IÑIGO NOVALES FLAMARIQUE
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Chromatic Adaptation ◽  
Molecular Component ◽  
Retinal Photoreceptors ◽  
Northern Anchovy ◽  
Vitamin A Derivative ◽  
Molecular Components ◽  
Human And Mouse ◽  
Dorsal Retina

AbstractVertebrate retinal photoreceptors house visual pigments that absorb light to begin the process of vision. The light absorbed by a visual pigment depends on its two molecular components: protein (opsin) and chromophore (a vitamin A derivative). Although an increasing number of studies show intraretinal variability in visual pigment content, it is only for two mammals (human and mouse) and two birds (chicken and pigeon) that such variability has been demonstrated to underlie differences in spectral sensitivity of the animal. Here, we show that the spectral sensitivity of the northern anchovy varies with retinal quadrant and that this variability can be explained by differences in the expression of opsin transcripts. Retinal (vitamin A1) was the only chromophore detected in the retina, ruling out this molecular component as a source of variation in spectral sensitivity. Chromatic adaptation experiments further showed that the dorsal retina had the capacity to mediate color vision. Together with published results for the ventral retina, this study is the first to demonstrate that intraretinal opsin variability in a fish drives corresponding variation in the animal’s spectral sensitivity.

scholarly journals Two visual pigment opsins, one expressed in the dorsal region and another in the dorsal and the ventral regions, of the compound eye of a dragonfly,Sympetrum frequens

1996 ◽  
Vol 2 (3) ◽  
pp. 209-209 ◽  
Author(s):  
Kentaro Arikawa ◽  
Koichi Ozaki ◽  
Takanari Tsuda ◽  
Junko Kitamoto ◽  
Yuji Mishina
Keyword(s):  
Visual Pigment ◽  
Compound Eye ◽  
Dorsal Region ◽  
Sympetrum Frequens

Light-Evoked Electrical Potentials from the Eye and Optic Nerve of Strombus: Response Waveform and Spectral Sensitivity

1974 ◽  
Vol 60 (2) ◽  
pp. 383-396
Author(s):  
HOWARD L. GILLARY
Keyword(s):  
Steady State ◽  
Optic Nerve ◽  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Synaptic Inhibition ◽  
Nerve Fibres ◽  
Electrical Potentials ◽  
Peak Absorption ◽  
Negative Erg ◽  
Sensitivity Studies

1. The cornea-negative ERG of the eye of Strombus exhibited two distinct ‘on’ peaks, a steady state during sustained illumination, and small rhythmic oscillations following the cessation of stimulation. 2. In certain afferent optic nerve fibres, illumination evoked phasic and tonic ‘on’ responses; others, whose activity was inhibited by light, responded with repetitive ‘off’ bursts which tended to occur in phase with the rhythmic ERG oscillations. 3. Spectral sensitivity studies indicate the presence of a single visual pigment with a peak absorption of about 485 nm. 4. The effects on the response of temperature and stimulus intensity and frequency were also examined. 5. The results indicate photo-excitation and synaptic inhibition of the receptors, and excitatory coupling between them.

Sign in / Sign up

Export Citation Format

Share Document