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.

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.

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.

Spectral sensitivity of monocularly deprived cats

1992 ◽  
Vol 9 (6) ◽  
pp. 617-622 ◽  
Author(s):  
Zijiang J. He ◽  
Michael S. Loop
Keyword(s):  
Spectral Sensitivity ◽  
Sensitivity Function ◽  
Monocular Deprivation ◽  
Stimulus Light ◽  
Large White ◽  
Sensitivity Functions ◽  
Increment Threshold ◽  
Normal Transition ◽  
Intensity Functions ◽  
Spectral Sensitivity Function

AbstractThe reports of rod-dominated psychophysical spectral sensitivity from the deprived eye of monocularly lid-sutured (MD) monkeys are intriguing but difficult to reconcile with the absence of any reported deprivation effects in retina. As most studies of MD retina have been from cat, we have examined psychophysically the increment threshold spectral sensitivity of MD cats using both reaction time and simultaneous two-choice behavioral procedures. Although the deprived eyes exhibited an absolute increment threshold sensitivity deficit, both rod and cone spectral sensitivity functions were obtained on large white backgrounds. This normal transition from rod to cone vision, as background luminance increased, was also found in threshold vs. intensity functions. Using their deprived eye, some cats exhibited a rod spectral sensitivity function when a smaller, normally photopic, background was used providing some support for a hypothesis that the rod-dominated spectral sensitivity observed in monkey may represent detection of scattered stimulus light. Alternatively monocular deprivation may reveal a rod-dominated mechanism which exists in monkey but not in cat.

Sensitivity to interaural intensity differences of neurons in primary auditory cortex of the cat. I. types of sensitivity and effects of variations in sound pressure level

1996 ◽  
Vol 75 (1) ◽  
pp. 75-96 ◽  
Author(s):  
D. R. Irvine ◽  
R. Rajan ◽  
L. M. Aitkin
Keyword(s):  
Auditory Cortex ◽  
High Frequency ◽  
Primary Auditory Cortex ◽  
Mirror Image ◽  
Sensitivity Function ◽  
Maximum Response ◽  
Binaural Interaction ◽  
Sensitivity Functions ◽  
Monaural Stimulation ◽  
Stimulation Of

1. Interaural intensity differences (IIDs) provide the major cue to the azimuthal location of high-frequency narrowband sounds. In recent studies of the azimuthal sensitivity of high-frequency neurons in the primary auditory cortex (field AI) of the cat, a number of different types of azimuthal sensitivity have been described and the azimuthal sensitivity of many neurons was found to vary as a function of changes in stimulus intensity. The extent to which the shape and the intensity dependence of the azimuthal sensitivity of AI neurons reflects features of their IID sensitivity was investigated by obtaining data on IID sensitivity from a large sample of neurons with a characteristic frequency (CF) > 5.5 kHz in AI of anesthetized cats. IID sensitivity functions were classified in a manner that facilitated comparison with previously obtained data on azimuthal sensitivity, and the effects of changes in the base intensity at which IIDs were introduced were examined. 2. IID sensitivity functions for CF tonal stimuli were obtained at one or more intensities for a total of 294 neurons, in most cases by a method of generating IIDs that kept the average binaural intensity (ABI) of the stimuli at the two ears constant. In the standard ABI range at which a function was obtained for each unit, five types of IID sensitivity were distinguished. Contra-max neurons (50% of the sample) had maximum response (a peak or a plateau) at IIDs corresponding to contralateral azimuths, whereas ipsi-max neurons (17%) had the mirror-image form of sensitivity. Near-zero-max neurons (18%) had a clearly defined maximum response (peak) in the range of +/- 10 dB IID, whereas a small group of tough neurons (2%) had a restricted range of minimal responsiveness with near-maximal responses at IIDs on either side. A final 18% of AI neurons were classified as insensitive to IIDs. The proportions of neurons exhibiting the various types of sensitivity corresponded closely to the proportions found to exhibit corresponding types of azimuthal sensitivity in a previous study. 3. There was a strong correlation between a neuron's binaural interaction characteristics and the form of its IID sensitivity function. Thus, neurons excited by monaural stimulation of only one ear but with either inhibitory, facilitatory, or mixed facilitatory-inhibitory effects of stimulation of the other ear had predominantly contra-max IID sensitivity (if contralateral monaural stimulation was excitatory) or ipsi-max sensitivity (if ipsilateral monaural stimulation was excitatory). Neurons driven weakly or not at all by monaural stimulation but facilitated binaurally almost all exhibited near-zero-max IID sensitivity. The exception to this tight association between binaural input and IID sensitivity was provided by neurons excited by monaural stimulation of either ear (EE neurons). Although EE neurons have frequently been considered to be insensitive to IIDs, our data were in agreement with two recent reports indicating that they can exhibit various forms of IID sensitivity: only 23 of 75 EE neurons were classified as insensitive and the remainder exhibited diverse types of sensitivity. 4. IID sensitivity was examined at two or more intensities (3-5 in most cases) for 84 neurons. The form of the IID sensitivity function (defined in terms of both shape and position along the IID axis) was invariant with changes in ABI for only a small proportion of IID-sensitive neurons (approximately 15% if a strict criterion of invariance was employed), and for many of these neurons the spike counts associated with a given IID varied with ABI, particularly at near-threshold levels. When the patterns of variation in the form of IID sensitivity produced by changes in ABI were classified in a manner equivalent to that used previously to classify the effects of intensity on azimuthal sensitivity, there was a close correspondence between the effects of intensity on corresponding types of azimuthal and IID sensitivity

scholarly journals FINDING DEFECTS IN AUTOMATIC CONTROL SYSTEMS BASED ON STRUCTURE SENSITIVITY FUNCTIONS AND ANALYSIS OF INTEGRAL ESTIMATES OF OUTPUT SIGNALS

2021 ◽  
pp. 47-55
Author(s):  
S.V. Shalobanov ◽  
◽  
S.S. Shalobanov ◽  
A.A. Aleksandrov ◽  
◽  
...  
Keyword(s):  
Dynamic System ◽  
Control Systems ◽  
Sensitivity Function ◽  
Structure Sensitivity ◽  
Automatic Control Systems ◽  
Sensitivity Functions ◽  
Continuous Dynamic System ◽  
Sign Analysis ◽  
Block Based ◽  
Continuous Dynamic

The paper presents an algorithm for defects screening in a continuous dynamic system with a depth of up to dynamic block based on the structure sensitivity function and the sign analysis of integral esti-mates of the output signals deviations.

APB differentially affects the cone contributions to the zebrafish ERG

2002 ◽  
Vol 19 (4) ◽  
pp. 521-529 ◽  
Author(s):  
SHANNON SASZIK ◽  
AMBER ALEXANDER ◽  
TIMOTHY LAWRENCE ◽  
JOSEPH BILOTTA
Keyword(s):  
Glutamate Receptors ◽  
Spectral Sensitivity ◽  
Visual Processing ◽  
Short Wavelength ◽  
Wavelength Region ◽  
Wave Component ◽  
Adult Zebrafish ◽  
Short Wavelength Region ◽  
Long Wavelength ◽  
Sensitivity Functions

APB (DL-2-amino-4-phosphonobutyric acid) has been found to affect the retinal processing of many vertebrate species as evidenced by the suppression of the b-wave component of the electroretinogram (ERG). The present study examined the effects of APB on the cone contributions to the ERG response of adult zebrafish (Danio rerio). ERG responses were obtained from light-adapted adult zebrafish following intravitreal injection of either saline alone or saline with various concentrations of APB ranging from 10 μm to 500 μM. Visual stimuli were 200-ms flashes of various wavelengths and irradiances. Spectral sensitivity functions were calculated from the irradiance versus response amplitude functions of the a-, b-, and d-wave components of the ERG response. Saline had no effects on the ERG response. However, APB had differential effects on the sensitivity of the b- and d-wave components. The effects of APB on the b-wave component were most apparent in the ultraviolet and short-wavelength portions (320–440 nm) of the spectral sensitivity function, although the b-wave was not completely eliminated at these wavelengths. APB-treated subjects were found to possess the same cone mechanisms (L-M and M-S) in the middle- and long-wavelength areas of the spectrum as saline injected subjects, although absolute sensitivity was lower for the APB-injected subjects. Spectral sensitivity based on the d-wave response was affected by APB but only in the short-wavelength region. All results appear to be independent of the APB dose. These results support the notion that glutamate receptors play a specific role in zebrafish visual processing. In addition, the effects of APB support recent anatomical evidence that the zebrafish retina may possess different types of glutamate receptors.

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