Light induced retinal screening pigment migration independent of visual cell activity

1981 ◽  
Vol 143 (3) ◽  
pp. 305-309 ◽  
Author(s):  
K. Hamdorf ◽  
G. H�glund
Keyword(s):  
Cell Activity ◽  
Visual Cell ◽  
Screening Pigment ◽  
Retinal Screening ◽  
Pigment Migration

Spectral sensitivity of retinal screening pigment migration in the frog

1969 ◽  
Vol 9 (3) ◽  
pp. 377-IN8 ◽  
Author(s):  
P.A. Liebman ◽  
S. Carroll ◽  
A. Laties
Keyword(s):  
Spectral Sensitivity ◽  
Screening Pigment ◽  
Retinal Screening ◽  
Pigment Migration

scholarly journals Red-shift of spectral sensitivity due to screening pigment migration in the eyes of a moth, Adoxophyes orana

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Aya Satoh ◽  
Finlay J. Stewart ◽  
Hisaharu Koshitaka ◽  
Hiroshi D. Akashi ◽  
Primož Pirih ◽  
...  
Keyword(s):  
Spectral Sensitivity ◽  
Red Shift ◽  
Adoxophyes Orana ◽  
Screening Pigment ◽  
Pigment Migration

Spectral sensitivity of screening pigment migration in the compound eye ofManduca sexta

1983 ◽  
Vol 153 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Richard H. White ◽  
Mark J. Banister ◽  
Ruth R. Bennett
Keyword(s):  
Spectral Sensitivity ◽  
Compound Eye ◽  
Screening Pigment ◽  
Pigment Migration

Visual Function in Four Antarctic Nototheniid Fishes

1989 ◽  
Vol 142 (1) ◽  
pp. 311-324 ◽  
Author(s):  
N. W. PANKHURST ◽  
J. C. MONTGOMERY
Keyword(s):  
Visual Function ◽  
Monochromatic Light ◽  
Antarctic Fish ◽  
Spectral Irradiance ◽  
Rod Outer Segments ◽  
Scotopic Vision ◽  
Outer Segments ◽  
Screening Pigment ◽  
Retinal Screening ◽  
Time Of Year

Visual function was investigated in the antarctic fish Pagothenia borchgrevinki (Boulenger), Trematomus bernacchii Boulenger, T. centronotus Regan and T. hansoni Boulenger. All Trematomus species have large anterior aphakic spaces (indicating a forward feeding vector), whereas Pagothenia does not. Pagothenia and T. hansoni, which both feed in the water column, lack the corneal iridescence displayed by T. bernacchii and T. centronotus. This is thought to relate to the importance of downwelling light for image formation in Pagothenia and T. hansoni. Absolute sensitivity thresholds to white and monochromatic light were measured using electroretinogram (ERG) responses in light- and dark-adapted Pagothenia and dark-adapted Trematomus species. Dark-adapted fish (retinal screening pigment withdrawn from rod outer segments) had thresholds of l.3×10−3μEm−2s−1 to a 200ms pulse of white light, whereas that of lightadapted Pagothenia (rod outer segments covered by the retinal screening pigment) was l.9×10−2μEm−2s−1. We suggest that the thresholds approximate threshold stimuli for rods and cones, respectively. Measurement of thresholds of light-adapted Pagothenia made using a behavioural measure (feeding responses) gave a threshold of 5×10−3μEm−2s−1. Limits for photopic and scotopic vision are predicted to be reached at depths of 20–40 and 30–60 m, respectively, under snow and ice conditions typically encountered at this time of year. ERG-determined spectral sensitivity curves peaked around 500 nm in all four species and matched the spectral irradiance under the ice. Shifts to longer wavelengths in spectral irradiance caused by sub-ice phytoplankton growth may degrade visual ability. Flicker fusion frequencies (FFFs) reached a maximum value of 15 Hz in Pagothenia at the maximum stimulus intensity used, but at environmentally realistic light intensities they were less than 8 Hz. FFFs were lower in all Trematomus species than in Pagothenia.

Reversed Light Reaction of the Screening Pigment in a Compound Eye Induced by Noradrenaline

1987 ◽  
Vol 42 (7-8) ◽  
pp. 973-976 ◽  
Author(s):  
Achim Juse ◽  
Gunnar Höglund ◽  
Kurt Hamdorf
Keyword(s):  
Compound Eye ◽  
Local Application ◽  
Pigment Cells ◽  
Light Stimulation ◽  
Light Reaction ◽  
Transmission Microscopy ◽  
Normal Dispersion ◽  
Screening Pigment ◽  
Pigment Migration ◽  
Deilephila Elpenor

Migration of the screening pigment in the compound eye of the sphingid moth Deilephila elpenor is altered by noradrenaline, as shown by microreflectometric measurements on eyes of intact moths and by transmission microscopy on preparations consisting of the screening pigment cells and dioptric structures. Local application of noradrenaline inverts the reaction of the pigment to light stimulation; light causes a contraction of the pigment instead of the normal dispersion. It is suggested that catecholamines are involved in the normal regulation of pigment migration.

scholarly journals SCREENING-PIGMENT MIGRATION IN THE OCTOPUS RETINA INCLUDES CONTROL BY DOPAMINERGIC EFFERENTS

1993 ◽  
Vol 185 (1) ◽  
pp. 1-16
Author(s):  
I. G. Gleadall ◽  
K. Ohtsu ◽  
E. Gleadall ◽  
Y. Tsukahara
Keyword(s):  
Receptor Potential ◽  
Supporting Cells ◽  
Optic Nerves ◽  
Optic Lobes ◽  
Screening Pigment ◽  
Early Receptor Potential ◽  
Pigment Migration ◽  
Dramatic Difference ◽  
Series Of Experiments ◽  
Neurotransmitter Substances

The extent of screening-pigment (SP) migration in the intact octopus retina and the amplitude of the early receptor potential (ERP) correspond with the degree of adaptation to light or darkness. The light-adapted retina has SP granules concentrated in an apical layer, at the tips of the photoreceptor rhabdoms and supporting cells, and the ERP is barely detectable. In the fully dark-adapted retina, the SP granules are mostly at the base of the rhabdoms, and the ERP is at its maximum. Retinae at intermediate stages, between the fully dark- and light-adapted states, show corresponding intermediate stages of SP migration and ERP amplitude. A series of experiments demonstrates the effects on SP migration of the efferent nerves, which form a subset of fibres in the optic nerves. When the optic nerves to one half of the retina have been severed, there is a dramatic difference in the distribution of SP in areas of the retina (of the dark-adapted eye) connected with severed or intact nerves: apical versus basal, respectively. On incubation of a light- adapted retina with 5 micromolar dopamine, but not with other catecholamines or other putative neurotransmitter substances, SP migrates basally and the ERP is significantly larger than for controls. In octopuses treated with reserpine, SP stays in an apical location and the ERP remains very small, regardless of the state of adaptation and of whether the optic nerves are intact. It is concluded that dopaminergic efferents from the optic lobes effect dark-adaptational SP migration in the cephalopod retina. The arrival in the retina of efferent signals that effect adaptational changes through the mediation of dopamine is a remarkable analogue of the vertebrate system.

scholarly journals Pigment Migration and Adaptation in the Eye of the Squid, Loligo pealei

1974 ◽  
Vol 63 (1) ◽  
pp. 22-36 ◽  
Author(s):  
N. W. Daw ◽  
A. L. Pearlman
Keyword(s):  
Absorption Spectrum ◽  
Time Course ◽  
Action Spectrum ◽  
Indirect Evidence ◽  
Screening Pigment ◽  
Pigment Migration ◽  
Optic Nerve Response ◽  
Loligo Pealei ◽  
Outward Migration

The migration of the screening pigment was investigated in the retina of the intact squid. The action spectrum of pigment migration corresponds to the action spectrum of the visual pigment, rhodopsin, rather than to the absorption spectrum of the screening pigment. The total number of quanta required for a fixed criterion of pigment migration is the same, when the quanta are delivered over any period of time from 6 s to an hour or more. When less than 3–10% of the rhodopsin is isomerized, the screening pigment migrates out to the tips of the receptors with a time-course of 5–15 min, and back again over the same period of time. When rather more than 10% is isomerized, the outward migration takes 5–15 min, but the screening pigment does not migrate inwards, even after several hours in the dark. Indirect evidence suggests that the band of screening pigment, when it reaches the tips of the receptors, is approximately equivalent to a filter of 0.6 log units. The spectral sensitivity of the optic nerve response was measured, and was found to be broader than the absorption spectrum of squid rhodopsin in vitro; the broadness could be explained by self-screening, assuming a density of rhodopsin of 0.6 log units at 500 nm.

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