Correlation of spinule dynamics and plasticity of the horizontal cell spectral response in cyprinid fish retina: quantitative analysis

1990 ◽  
Vol 260 (1) ◽  
pp. 123-130 ◽  
Author(s):  
Matthias Kirsch ◽  
Mustafa B. A. Djamgoz ◽  
Hans-Joachim Wagner
Keyword(s):  
Quantitative Analysis ◽  
Spectral Response ◽  
Horizontal Cell ◽  
Cyprinid Fish ◽  
Fish Retina

Plasticity of cone horizontal cell functioning in cyprinid fish retina: effects of background illumination of moderate intensity

1988 ◽  
Vol 17 (5) ◽  
pp. 701-710 ◽  
Author(s):  
M. B. A. Djamgoz ◽  
J. E. G. Downing ◽  
M. Kirsch ◽  
D. J. Prince ◽  
H. -J. Wagner
Keyword(s):  
Horizontal Cell ◽  
Cyprinid Fish ◽  
Moderate Intensity ◽  
Background Illumination ◽  
Fish Retina

A horizontal cell selectively contacts blue-sensitive cones in cyprinid fish retina : intracellular staining with horseradish peroxidase

1988 ◽  
Vol 235 (1280) ◽  
pp. 281-287 ◽  
Keyword(s):  
Horseradish Peroxidase ◽  
Negative Feedback ◽  
Horizontal Cell ◽  
Cyprinid Fish ◽  
Horizontal Cells ◽  
Intracellular Staining ◽  
Yellow Orange ◽  
Fish Retina ◽  
Feedback Pathway

A horizontal cell selectively contacting blue-sensitive cones has been intracellularly stained with horseradish peroxidase in the retina of a cyprinid fish, the roach. The light microscopical morphology of the cell belonged to the H3 category of horizontal cells found in cyprinid fish retinae. In response to spectral stimuli, the cell generated chromaticity-type S-potentials that were hyperpolarizing to blue and depolarizing to yellow-orange. A red-sensitive hyperpolarizing component was absent possibly because of suppression of the negative feedback pathway between luminosity-type (H1) horizontal cells and green-sensitive cones.

Depletion of retinal dopamine does not affect the ERG b-wave increment threshold function in goldfish in vivo

1994 ◽  
Vol 11 (4) ◽  
pp. 695-702 ◽  
Author(s):  
Zheng-Shi Lin ◽  
Stephen Yazulla
Keyword(s):  
Horizontal Cell ◽  
Threshold Function ◽  
Photopic Vision ◽  
Threshold Functions ◽  
Increment Threshold ◽  
Intensity Response ◽  
Purkinje Shift ◽  
6 Hydroxydopamine ◽  
Fish Retina

AbstractIncrement threshold functions of the electroretinogram (ERG) b–wave were obtained from goldfish using an in vivo preparation to study intraretinal mechanisms underlying the increase in perceived brightness induced by depletion of retinal dopamine by 6–hydroxydopamine (6–OHDA). Goldfish received unilateral intraocular injections of 6–OHDA plus pargyline on successive days. Depletion of retinal dopamine was confirmed by the absence of tyrosine-hydroxylase immunoreactivity at 2 to 3 weeks postinjection as compared to sham-injected eyes from the same fish. There was no difference among normal, sham-injected or 6–OHDA-injected eyes with regard to ERG waveform, intensity-response functions or increment threshold functions. Dopamine-depleted eyes showed a Purkinje shift, that is, a transition from rod-to-cone dominated vision with increasing levels of adaptation. We conclude (1) dopamine-depleted eyes are capable of photopic vision; and (2) the ERG b–wave is not diagnostic for luminosity coding at photopic backgrounds. We also predict that (1) dopamine is not required for the transition from scotopic to photopic vision in goldfish; (2) the ERG b–wave in goldfish is influenced by chromatic interactions; (3) horizontal cell spinules, though correlated with photopic mechanisms in the fish retina, are not necessary for the transition from scotopic to photopic vision; and (4) the OFF pathway, not the ON pathway, is involved in the action of dopamine on luminosity coding in the retina.

Acid phosphatase localization in endocytosed horizontal cell gap junctions

1992 ◽  
Vol 8 (1) ◽  
pp. 77-81 ◽  
Author(s):  
Dana K. Vaughan ◽  
Eric M. Lasater
Keyword(s):  
Acid Phosphatase ◽  
Horizontal Cell ◽  
Vesicle Fusion ◽  
White Bass ◽  
Degradative Pathway ◽  
Transport Vesicles ◽  
Subsequent Step ◽  
Degradative Enzymes ◽  
Fish Retina ◽  
Conventional Electron Microscopy

AbstractGap junction (GJ) endocytosis appears to be part of a cycle of GJ renewal in horizontal cells of the teleost fish retina. At least three stages of GJ endocytosis in these neurons have been identified using conventional electron microscopy (EM): invagination of GJ membranes (GJ blebs); free GJ vesicles; and GJ vesicle fusion with mature lysosomes (Vaughan & Lasater, 1990a). In the present study, EM-level acid phosphatase (AP) histochemistry of white bass retina was used to determine at what stage enzymatic degradation of endocytosed GJs begins. Electron-dense AP reaction product was observed within the trans face of the Golgi apparatus, mature lysosomes, and occasional, internal GJ vesicles. In contrast, GJ blebs, peripheral GJ vesicles, and most internal GJ vesicles lacked AP reaction product. These results support the idea that at least some of the GJ vesicles observed within these retinal neurons arise from endocytosis, are on a degradative pathway, and can be termed GJ “endosomes.” Furthermore, GJ vesicles appear to be initially free of AP, but some later acquire it (presumably from transport vesicles bearing degradative enzymes). It is still unclear whether our previous report of GJ vesicle fusion with mature lysosomes is a subsequent step in GJ degradation or part of a different degradative pathway altogether.

scholarly journals Ice Crystal Characterization in Cirrus Clouds II: Radiometric Characterization of HaloCam for the Quantitative Analysis of Halo Displays

2020 ◽  
Author(s):  
Linda Forster ◽  
Meinhard Seefeldner ◽  
Andreas Baumgartner ◽  
Tobias Kölling ◽  
Bernhard Mayer
Keyword(s):  
Surface Roughness ◽  
Quantitative Analysis ◽  
Radiative Transfer ◽  
Spectral Response ◽  
Observation System ◽  
Measured Signal ◽  
Ice Crystal ◽  
Geometric Calibration ◽  
The Absolute

Abstract. This study presents the weather-proof RGB camera HaloCam_RAW, which is part of the automated halo observation system HaloCam and designed for the quantitative analysis of halo displays. We present a procedure for both the geometric and absolute radiometric characterization of HaloCam_RAW and demonstrate its application in a case study. The geometric calibration was performed using a chessboard pattern to estimate camera matrix and distortion coefficients. For the radiometric characterization of HaloCam_RAW, dark signal and vignetting effect were determined to correct the measured signal. Furthermore, the spectral response of the RGB sensor and the linearity of its radiometric response were characterized. The absolute radiometric response was determined by cross-calibrating HaloCam_RAW against the completely characterized specMACS imager. For a typical measurement signal the relative (absolute) radiometric uncertainty amounts to 2.8 % (5.0 %), 2.4 % (5.8 %), and 3.3 % (11.8 %) for the Red, Green, and Blue channel, respectively. The absolute radiometric uncertainty estimate is larger mainly due to the inhomogeneity of the scene used for cross-calibration and the absolute radiometric uncertainty of specMACS. Geometric and radiometric characterization of HaloCam_RAW were applied to a scene with a 22° halo observed on 21 April 2016. The observed radiance distribution and 22° halo ratio compared well with radiative transfer simulations assuming a range of ice crystal habits and surface roughness. This application demonstrates the potential of developing a retrieval method for ice crystal properties, such as ice crystal size, shape and surface roughness using calibrated HaloCam_RAW observations together with radiative transfer simulations.

scholarly journals Ice crystal characterization in cirrus clouds II: radiometric characterization of HaloCam for the quantitative analysis of halo displays

2020 ◽  
Vol 13 (7) ◽  
pp. 3977-3991
Author(s):  
Linda Forster ◽  
Meinhard Seefeldner ◽  
Andreas Baumgartner ◽  
Tobias Kölling ◽  
Bernhard Mayer
Keyword(s):  
Surface Roughness ◽  
Quantitative Analysis ◽  
Radiative Transfer ◽  
Spectral Response ◽  
Observation System ◽  
Measured Signal ◽  
Ice Crystal ◽  
Geometric Calibration ◽  
The Absolute

Abstract. We present a procedure for geometric, spectral, and absolute radiometric characterization of the weather-proof RGB camera HaloCamRAW and demonstrate its application in a case study. This characterization procedure can be generalized to other RGB camera systems with similar field of view. HaloCamRAW is part of the automated halo observation system HaloCam and designed for the quantitative analysis of halo displays. The geometric calibration was performed using a chessboard pattern to estimate camera matrix and distortion coefficients. For the radiometric characterization of HaloCamRAW, the dark signal and vignetting effect were determined to correct the measured signal. Furthermore, the spectral response of the RGB sensor and the linearity of its radiometric response were characterized. The absolute radiometric response was estimated by cross calibrating HaloCamRAW against the completely characterized spectrometer of the Munich Aerosol Cloud Scanner (specMACS). For a typical measurement signal the relative (absolute) radiometric uncertainty amounts to 2.8 % (5.0 %), 2.4 % (5.8 %), and 3.3 % (11.8 %) for the red, green, and blue channel, respectively. The absolute radiometric uncertainty estimate is larger mainly due to the inhomogeneity of the scene used for cross calibration and the absolute radiometric uncertainty of specMACS. Geometric and radiometric characterization of HaloCamRAW were applied to a scene with a 22∘ halo observed on 21 April 2016. The observed radiance distribution and 22∘ halo ratio compared well with radiative transfer simulations assuming a range of ice crystal habits and surface roughness values. This application demonstrates the potential of developing a retrieval method for ice crystal properties, such as ice crystal size, shape, and surface roughness using calibrated HaloCamRAW observations together with radiative transfer simulations.

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