scholarly journals Spectral Sensitivity of the Common Prawn, Palaemonetes vulgaris

1968 ◽  
Vol 51 (5) ◽  
pp. 694-700 ◽  
Author(s):  
George Wald ◽  
Edward B. Seldin
Keyword(s):  
Spectral Sensitivity ◽  
Dark Adaptation ◽  
Visual Pigment ◽  
Red Light ◽  
Relative Number ◽  
Sensitivity Function ◽  
The Common ◽  
Colored Lights ◽  
Spectral Sensitivity Function ◽  
Spectral Sensitivity Curve

The vision of Palaemonetes is of particular interest in view of extensive studies of the responses of its chromatophore systems and eye pigments to light. The spectral sensitivity is here examined under conditions of dark adaptation and adaptation to bright colored lights. In each case the relative number of photons per one-fiftieth sec flash needed to evoke a constant peak amplitude (usually 25 or 50 µv) in the electroretinogram (ERG) was measured at various wavelengths throughout the spectrum. The sensitivity is the reciprocal of this number. In dark-adapted animals the spectral sensitivity curve consists of a broad, almost symmetrical band, maximal at about 540 mµ, with a shoulder near 390 mµ. Adaptation to bright red or blue light, left on continuously throughout the measurements, depresses the 540 mµ peak without notably changing its shape or position, implying that only one visual pigment operates in this region. Adaptation to red light, however, spares a violet-sensitive system, so that a high, narrow peak at 390 mµ now dominates the spectral sensitivity function. The 540 and 390 mµ peaks are apparently associated with different visual pigments; and these seem to be segregated in different receptor systems, since the associated ERG's have markedly different time constants. It is suggested that these two sensitivity bands may represent the red- and violet-sensitive components of an apparatus for color differentiation.

Light-evoked contraction of red absorbing cones in the Xenopus retina is maximally sensitive to green light

1992 ◽  
Vol 8 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Joseph C. Besharse ◽  
Paul Witkovsky
Keyword(s):  
Xenopus Laevis ◽  
Spectral Sensitivity ◽  
Red Light ◽  
Green Light ◽  
Sensitivity Function ◽  
Direct Mechanism ◽  
Sensitivity Experiments ◽  
Light Stimuli ◽  
The Difference ◽  
Spectral Sensitivity Function

AbstractTo test the hypothesis that light-evoked cone contraction in eye cups from Xenopus laevis is controlled through a direct mechanism initiated by the cone's own photopigment, we conducted spectral-sensitivity experiments. We estimate that initiation of contraction of red absorbing cones (611 nm) is 1.5 log units more sensitive to green (533 nm) than red (650 nm) light stimuli. The difference is comparable to that predicted from the spectral-sensitivity function of the green absorbing, principal rod (523 nm). Furthermore, 480-nm and 580-nm stimuli which are absorbed nearly equally by the principal rod have indistinguishable effects on cone contraction. We also found that light blockade of nighttime cone elongation is much more sensitive to green than to red light stimuli. Our observations are inconsistent with the hypothesis tested, and suggest that light-regulated cone motility is controlled through an indirect mechanism initiated primarily by the green absorbing, principal rod.

Diurnal control of rod function in the chicken

1991 ◽  
Vol 6 (6) ◽  
pp. 641-653 ◽  
Author(s):  
Frank Schaeffel ◽  
Baerbel Rohrer ◽  
Eberhart Zrenner ◽  
Thomas Lemmer
Keyword(s):  
Spectral Sensitivity ◽  
Dark Adaptation ◽  
Wave Amplitude ◽  
Light And Electron Microscopy ◽  
Sensitivity Function ◽  
Two Phase ◽  
Flickering Light ◽  
Amplitude Criterion ◽  
Rod Function ◽  
Spectral Sensitivity Function

AbstractWe studied rod function in the chicken by recording corneal electroretinograms (ERGs). The following experiments were performed to demonstrate rod function during daytime: (1) determining the dark-adaptation function; (2) measuring the spectral sensitivity by a a–b-wave amplitude criterion in response to monochromatic flickering light of different frequencies ranging from 6.5–40.8 Hz (duty cycle 1: I); (3) analyzing the response vs. log stimulus intensity (V–log I) function in order to reveal a possible two phase process; and (4) determining the spectral sensitivity function either in a non-dark adapted state or after dark adaptation of the animals for I and 24 h. None of these experiments demonstrated clear evidence of rod function during daytime. On the other hand, we found rods histologically by light- and electron microscopy. Therefore, we repeated our ERG recordings during the night (between midnight and 3:00 A.M.). Without previous dark adaptation, rod function could be seen immediately in the same experiments described above. The result shows that, in the chicken, rods are turned on endogenously during the night but are scarcely functional during the day.

Tetrachromatic input to turtle horizontal cells

2001 ◽  
Vol 18 (5) ◽  
pp. 759-765 ◽  
Author(s):  
Y. ZANA ◽  
D.F. VENTURA ◽  
J.M. de SOUZA ◽  
R.D. DeVOE
Keyword(s):  
Spectral Sensitivity ◽  
Horizontal Cell ◽  
Sensitivity Function ◽  
Horizontal Cells ◽  
Chromatic Adaptation ◽  
Morphological Evidence ◽  
Cone Type ◽  
Response Method ◽  
Uv Cone ◽  
Spectral Sensitivity Function

Recent physiological experiments support behavioral and morphological evidence for a fourth type of cone in the turtle retina, maximally sensitive in the ultraviolet (UV). This cone type has not yet been included in the models proposed for connectivity between cones and horizontal cells. In this study, we examined the inputs of UV, S, M, and L cones to horizontal cells. We used the high-resolution Dynamic Constant Response Method to measure the spectral sensitivity of horizontal cells without background light and after adaptation to UV, blue (B), green (G), and red (R) light. We concluded the following: (1) Tetrachromatic input to a Y/B horizontal cell was identified. The spectral-sensitivity curves of the cell in three of the adaptation conditions were well represented by L-, M-, and S-cone functions. Adaptation to blue light revealed a peak at 372 nm, the same wavelength location as that determined behaviorally in the turtle. A porphyropsin template could be closely fitted to the sensitivity band in that region, strong evidence for input from a UV cone. (2) The spectral-sensitivity functions of R/G horizontal cells were well represented by the L- and M-cone functions. There was no indication of UV- or S-cone inputs into these cells. (3) The spectral sensitivities of the monophasic horizontal cells were dominated by the L cone. However, the shape of the spectral-sensitivity function depended on the background wavelength, indicating secondary M-cone input. Connectivity models of the outer retina that predict input from all cone types are supported by the finding of tetrachromatic input into Y/B horizontal cells. In contrast, we did not find tetrachromatic input to R/G and monophasic horizontal cells. Chromatic adaptation revealed the spectral-sensitivity function of the turtle UV cone peaking at 372 nm.

scholarly journals The Electroretinogram of a Diurnal Gecko

1962 ◽  
Vol 45 (6) ◽  
pp. 1145-1161 ◽  
Author(s):  
G. B. Arden ◽  
Katharine Tansley
Keyword(s):  
Spectral Sensitivity ◽  
Stimulus Intensity ◽  
Dark Adaptation ◽  
Chromatic Adaptation ◽  
Flicker Fusion Frequency ◽  
Fusion Frequency ◽  
Flicker Response ◽  
Dark Adaptation Curve ◽  
Flicker Fusion ◽  
Spectral Sensitivity Curve

Using the electroretinogram as the criterion of retinal activity the flicker fusion frequency, course of dark adaptation, and spectral sensitivity of the pure cone retina of the diurnal gecko, Phelsuma inunguis, were investigated. Both the curve relating flicker fusion frequency to stimulus intensity and that relating the amplitude of the flicker response to stimulus intensity showed a break as the intensity was increased. The dark adaptation curve was that typical of cone retinae; there was no break, adaptation was relatively rapid, and there was a total increase of sensitivity of only about 3 log units. The spectral sensitivity curve showed two maxima, a major one at about 560 mµ and another at about 460 mµ. Chromatic adaptation with red and blue lights demonstrated the presence of two independent mechanisms. Although red adaptation could not have had a direct effect on the pigment responsible for the "blue" mechanism the sensitivity of this mechanism was depressed by red adaptation. The possible relationships of the two mechanisms are discussed.

scholarly journals A Corrected Formula for the Spectral Sensitivity Function in Radio Astronomy

1962 ◽  
Vol 15 (3) ◽  
pp. 445 ◽  
Author(s):  
RN Bracewell
Keyword(s):  
Spectral Sensitivity ◽  
Radio Astronomy ◽  
Sensitivity Function ◽  
Aperture Distribution ◽  
Spectral Sensitivity Function

According to Bracewell and Roberts (1954) the spectral sensitivity function .1(s) is calculated from an aerial aperture distribution .

The Sensitivity of Housefly Photoreceptors in the Mid-Ultraviolet and the Limits of the Visible Spectrum

1968 ◽  
Vol 49 (3) ◽  
pp. 669-677
Author(s):  
TIMOTHY H. GOLDSMITH ◽  
HECTOR R. FERNANDEZ
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Visible Spectrum ◽  
Wild Type ◽  
Long Wavelength ◽  
Wavelength Limit ◽  
Sharp Band ◽  
In The Wild ◽  
Filtering Effect ◽  
Spectral Sensitivity Curve

1. The spectral sensitivity of the photoreceptors of a white-eye mutant of the housefly Musca domestica has been measured to 250 nm. in the mid-ultraviolet. Maximum sensitivity is at 340-350 nm., as in the wild-type eye, and decreases at shorter wavelengths with a distinct shoulder at 280 nm. 2. Microspectrophotometric measurements of individual corneal facets show little absorption at wavelengths longer than 300 nm. but a sharp band (peak density about 0.4) at 277 nm. Adjustment of the spectral sensitivity curve for the filtering effect of the cornea makes the 280 nm. shoulder more prominent, suggesting the presence of energy transfer from the protein component of the visual pigment to the chromophore. 3. The short-wavelength limit of the housefly's visible spectrum is determined by the availability of ultraviolet light and is about 300 nm. in nature. The long-wavelength limit is set by the falling absorption of the visual pigment in the red.

Cone contributions to the photopic spectral sensitivity of the zebrafish ERG

1998 ◽  
Vol 15 (6) ◽  
pp. 1029-1037 ◽  
Author(s):  
ALAN HUGHES ◽  
SHANNON SASZIK ◽  
JOSEPH BILOTTA ◽  
PAUL J. DEMARCO ◽  
WARREN F. PATTERSON
Keyword(s):  
Spectral Sensitivity ◽  
Danio Rerio ◽  
Sensitivity Function ◽  
Chromatic Adaptation ◽  
Wave Component ◽  
Background Condition ◽  
Fundamental Properties ◽  
Increment Threshold ◽  
Cone Photopigments ◽  
Spectral Sensitivity Function

Microspectrophotometry studies show that zebrafish (Danio rerio) possess four cone photopigments. The purpose of this study was to determine the cone contributions to the zebrafish photopic increment threshold spectral-sensitivity function. Electroretinogram (ERG) b-wave responses to monochromatic lights presented on a broadband or chromatic background were obtained. It was found that under the broadband background condition, the zebrafish spectral-sensitivity function showed several peaks that were narrower in sensitivity compared to the cone spectra. The spectral-sensitivity function was modeled with L − M and M − S opponent interactions and nonopponent S- and U-cone mechanisms. Using chromatic adaptation designed to suppress the contribution of the S-cones, a strong U-cone contribution to the spectral-sensitivity function was revealed, and the contributions of the S-cones to the M − S mechanism were reduced. These results show that the b-wave component of the ERG receives input from all four cone types and appears to reflect color opponent mechanisms. Thus, zebrafish may possess the fundamental properties necessary for color vision.

Spectral sensitivity of the horse fly Tabanus nigrovittatus (Diptera: Tabanidae)

1991 ◽  
Vol 69 (2) ◽  
pp. 369-374 ◽  
Author(s):  
S. A. Allan ◽  
J. G. Stoffolano Jr. ◽  
R. R. Bennett
Keyword(s):  
Spectral Sensitivity ◽  
Red Light ◽  
Sensitivity Function ◽  
Sensitivity Functions ◽  
Green Sensitivity ◽  
Separate System ◽  
Horse Flies ◽  
Tabanus Nigrovittatus ◽  
Old Females ◽  
Older Males

Spectral sensitivity functions were calculated from electroretinograms recorded from dark-adapted compound eyes of male and female horse flies (Tabanus nigrovittatus Macquart). Females had a broad sensitivity in the violet to green area of the spectrum; their spectral sensitivity was fitted by a theoretical mixture containing 20% of 440-nm and 80% 520-nm rhodopsins. Older females (8–18 days) were 93 times more sensitive than 1-day-old females. Males showed a narrower sensitivity function with more blue and less green sensitivity. Older males (8–18 days) were the most blue-sensitive of all groups; their spectral sensitivity was best fitted by a mixture containing 10% 440-nm, 70% 480-nm, and 20% 520-nm rhodopsins. Older males that were light-adapted to red light showed an apparent decline in the contribution of the 520-nm rhodopsin to overall sensitivity, as expected if this pigment is present in a separate system. The sensitivity function of 1-day-old males was best fitted by a mixture of 55% 480-nm and 45% 520-nm rhodopsins. The absolute sensitivity of both groups of males was close to that of the older females. All flies had substantial ultraviolet sensitivity, averaging 67% of the sensitivity at the longer wavelength maximum. The role of the differing sensitivities in males and females, and in young and old females, is discussed in relation to the visual behavior and sexual dimorphism of horse flies.

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