Ionochromic properties of long-wave-sensitive cones in the goldfish retina: an electrophysiological and microspectrophotometric study (original) (raw)
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Spectral sensitivity of cones in the goldfish, Carassius auratus
Vision Research, 1998
The spectral sensitivities of retinal cones isolated from goldfish (Carassius auratus) retinas were measured in the range 277-737 nm by recording membrane photocurrents with suction pipette electrodes (SPE). Cones were identified with u max ( 9 S.D.) at 6239 6.9 nm, 537 9 4.7 nm, 447 9 7.7 nm, and about 356 nm (three cells). Two cells (u max 572 and 576 nm) possibly represent genetic polymorphism. A single A 2 template fits the h-band of P447 2 , P537 2 , and P623 2 . HPLC analysis showed 4% retinal:96% 3-dehydroretinal. Sensitivity at 280 nm is nearly half that at the u max in the visible. The u max of the i-band (in nm) is a linear function of the u max of the h-band and follows the same relation as found for A 1 -based cone pigments of a cyprinid fish.
The Journal of General Physiology, 1996
Removal of extracellular Cl- has been shown to suppress light-evoked voltage responses of ON bipolar and horizontal cells, but not photoreceptors or OFF bipolar cells, in the amphibian retina. A substantial amount of experimental evidence has demonstrated that the photoreceptor transmitter, L-glutamate, activates cation, not Cl-, channels in these cells. The mechanism for Cl-free effects was therefore reexamined in a superfused retinal slice preparation from the mudpuppy (Necturus maculosus) using whole-cell voltage and current clamp techniques. In a Cl-free medium, light-evoked currents were maintained in rod and cone photoreceptors but suppressed in horizontal, ON bipolar, and OFF bipolar cells. Changes in input resistance and dark current in bipolar and horizontal cells were consistent with the hypothesis that removal of Cl- suppresses tonic glutamate release from photoreceptors. The persistence of light-evoked voltage responses in OFF bipolar cells, despite the suppression of li...
General Physiology and Biophysics, 2009
Photoreceptor content of fish retinas could be accessed by comparative electroretinographic (ERG) studies using flickering light stimuli that could separate rod-mediated vision where critical flicker frequency (CFF, frequency when the eye loses its ability to resolve individual light pulses) is usually less than 15 Hz from cone-mediated vision. Four fish species inhabiting different photic environments (small-spotted dogfish shark -Scyliorhinus canicula, eel -Anguilla anguilla, painted comber -Serranus scriba, Prussian carp -Carassius gibelio) were investigated. Dogfish shark b-wave amplitudes significantly decreased at low frequency of stimulation and CFF was reached at 3.2 Hz. A similar effect on the b-wave amplitude was observed in the eel, but CFF occurred at around 20 Hz. Conversely, b-waves of painted comber and Prussian carp remained unaltered under intermittent low-frequency stimulation, and CFFs were around 25 and 30 Hz, respectively. Additional support in accessing the receptor content of fish retinas was given by the characterization of the OFF-response (d-wave) after light adaptation. Monotonous time course of the b-wave dark adaptation indicated a rod dominated retina of the dogfish shark.
Chloride currents in cones modify feedback from horizontal cells to cones in goldfish retina
The Journal of Physiology, 2012
• The GABAergic pathway modulates feedback between retinal horizontal cells (HCs) and cone photoreceptors, but is not mediating negative feedback, as previously hypothesized. • Opening of GABA-gated chloride channels in cone photoreceptors reduces the amplitude of feedback responses generated by HCs. • Activation of a different presynaptic chloride current, the calcium-dependent chloride current, in individual cones has a similar effect on feedback as application of GABA. • Modulation of the strength of feedback from HCs seems to be a general consequence of activation of presynaptic chloride currents in cones. • This puts the functional role of these currents in a new perspective; GABA acts as a slow and global neuromodulator enhancing feedback in the light-and attenuating feedback in the dark-adapted retina, whereas the calcium-dependent chloride current modulates feedback fast and locally to tune the size of feedback to local light conditions.
Activity of long-wavelength cones under scotopic conditions in the cyprinid fish Danio aequipinnatus
Journal of Comparative Physiology A: Sensory, Neural, and Behavioral Physiology, 1997
In carp (Cyprinus) and gold®sh (Carassius), long-wavelength cones are reported to be active under scotopic conditions. Using the electroretinogram (ERG), we tested another cyprinid ®sh, Danio aequipinnatus, which contains A 1 -based visual pigments and for which we had previously measured the spectral sensitivities of individual cones. Dark adaptation curves show a rod/cone break at about 45 min. When thoroughly dark-adapted, the spectral sensitivity function is broader than can be accounted for by self-screening of rhodopsin, but it can be modeled by an additive combination of rods and the 560-nm cones. Dim, red background light causes adaptation of rods and a broadening of the spectral sensitivity function, which can be simulated by increasing the proportion of cones in the model. Brighter red backgrounds adapt the 560-nm cones. Because of the eect of red adapting lights, the ERG evidence for the participation of longwavelength cones close to visual threshold appears to be dierent in Danio than in the gold®sh Carassius.
Green-sensitive cone photoreceptors are selectively labeled by Procion yellow dye in goldfish retina
Visual Neuroscience, 1991
Selective labeling of intravitreal Procion yellow dye by presumed blue-sensitive cone photoreceptors has been demonstrated in primate retina. To determine whether Procion yellow is selective for this cone type in an unrelated vertebrate species, labeling by this dye was studied in goldfish retina, where cone pigment type can be directly inferred from photoreceptor morphology. At low vitreal concentrations of the dye (<0.4%), only cone outer segments were labeled. At vitreal concentrations of 0.4–0.5%, the inner segments of short-double cones and a subset of long single cones (presumed green-sensitive cones) were selectively stained. At still higher vitreal concentrations (0.6–0.7%), the inner segments of short-single cones and miniature short-single cones (presumed blue-sensitive cones) showed evidence of Procion label, but were not as heavily labeled. The inner segments of long-double cones and a subset of long-single cones (presumed red-sensitive cones) did not label at any of ...
Vision research, 1972
FURUKAWA and HANAWA (1955) first showed that replacing part of the chloride in Ringer's solution with aspartate suppresses PII of the ERG but leaves a stable PIII. Since it is known that PI11 of the vertebrate retina has a distal and a proximal component (MIJRAKAMI and KANEKO, 1966) it remained for SILLMAN, ITO and TOMITA (1969) to show that aspartate eliminates proximal PIII, leaving unaffected the receptor response, distal PIII. Recently, WITKOVSKY, NELSON and RIPPS (1971) have shown that a long latency, slow potential of non-receptor origin remains after aspartate treatment. However, the early portion of the response, including the initial amplitude, is generated in the receptor layer. In the present study the slow potential was not seen after 92 per cent of the rod pigment rhodopsin was bleached.
Spectral sensitivity of the feedback signal from horizontal cells to cones in goldfish retina
Visual Neuroscience, 1998
The spectral sensitivity of cones in isolated goldfish retina was determined with whole-cell recording techniques. Three spectral classes of cones were found with maximal sensitivities around 620 nm, 540 nm, and 460 nm. UV-cones were not found because our stimulator did not allow effective stimulation in the UV range. The spectral sensitivity of the cones closely matched the cone photopigment absorption spectra at the long wavelength side of the spectrum, but deviated significantly at shorter wavelengths. Surround stimulation induced an inward current in cones due to feedback from horizontal cells. The spectral sensitivity of this feedback signal was determined in all three cone classes and found to be broader than the spectral sensitivity of the cones recorded from, and to be spectrally nonopponent. These data are consistent with a connectivity scheme between cones and horizontal cells in which the three horizontal cell systems feed back to all cone systems and in which all horizon...
Response properties of cones from the retina of the tiger salamander
The Journal of Physiology, 1991
1. Spectral sensitivity measurements using the suction electrode technique reveal three types of cone in the retina of the tiger salamander, showing maximum sensitivity at wavelengths 610 nm (red-sensitive cone), 444 nm (blue-sensitive cone) and below 400 nm (UV-sensitive cone).