Background-induced flicker enhancement in cat retinal horizontal cells. I. Temporal and spectral properties

1990 ◽  
Vol 64 (2) ◽  
pp. 313-325 ◽  
Author(s):  
R. Pflug ◽  
R. Nelson ◽  
P. K. Ahnelt
Keyword(s):  
Light Adaptation ◽  
Dynamic Range ◽  
Horizontal Cell ◽  
Plexiform Layer ◽  
Horizontal Cells ◽  
Enhancement Effect ◽  
Long Wavelength ◽  
Flicker Response ◽  
Response Enhancement ◽  
Cone Signal

1. Dim backgrounds can enhance small-spot flicker responses of cat retinal horizontal cells by a factor of 2 or more. 2. Intracellular marking with horseradish peroxidase (HRP) reveals that this enhancement effect occurs in--but is not necessarily limited to--the cone-connected, A-type horizontal cell. 3. Flicker amplitudes decrease over a frequency range from 3 to 36 Hz of square-wave photic stimulation. There is little evidence of flicker-response enhancement at 3 Hz. Flicker-response enhancement is typically 2-6 times larger at 35 than at 6 Hz. 4. Inspection of flicker waveforms indicates both a scaling-up of response signals with backgrounds and a distortion composed of 2- to 5-ms-latency decrease, expressed primarily within a quick component of OFF-repolarization. 5. Flicker enhancement first increases as a function of background irradiance and then decreases. The increasing limb has the dynamic range and spectral sensitivity of cat rods (507-nm peak). Enhancement is maintained during rod after-effects. The decreasing limb of the background-versus-intensity function results from light adaptation of cat, long-wavelength (red) cones. 6. The flicker responses themselves peak spectrally at approximately 555 nm and reflect only the activity of cat long-wavelength (red) cones, without evidence of intermixing of other photoreceptor mechanisms. 7. Thus within the first synaptic layer of the cat visual system, rod signals interact with the flicker responses of red cones, both increasing cone-signal amplitudes and modifying cone-signal waveforms. 8. The results are closely analogous to "suppressive rod-cone interaction" (SRCI) as described in human psychophysics. 9. An outer-plexiform-layer circuit involving rods, horizontal cells and cones may mediate rod-induced enhancement of cone flicker. This being the case, notions of horizontal-cell feedback interactions with cones may have to be modified and extended. A specific feedback model is elaborated in the companion paper.

Effects of light adaptation on contrast processing in bipolar cells in the retina

2001 ◽  
Vol 18 (4) ◽  
pp. 581-597 ◽  
Author(s):  
PATRICK K. FAHEY ◽  
DWIGHT A. BURKHARDT
Keyword(s):  
Light Adaptation ◽  
Dynamic Range ◽  
Horizontal Cell ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Background Intensity ◽  
Ambystoma Tigrinum ◽  
Background Illumination ◽  
Voltage Range ◽  
Contrast Gain

Effects of light adaptation on contrast processing in the outer retina were investigated over nearly four decades of background illumination by analyzing the intracellular responses of 111 bipolar cells, 66 horizontal cells, and 22 cone photoreceptors in the superfused eyecup of the tiger salamander (Ambystoma tigrinum). Light adaptation had striking and similar effects on the average contrast responses of the hyperpolarizing (Bh) and depolarizing (Bd) classes of bipolar cells: Over the lower two decades of background illumination, the contrast gain increased 7-fold to reach values as high as 20–30, the dynamic range and the half-maximum contrast decreased by about 60%, the total voltage range increased some 40%, and contrast dominance changed from highly positive to more balanced. At higher levels of background, most aspects of the contrast response stabilized and Weber's Law then held closely. In this background range, the contrast gain of bipolar cells was amplified some 20× relative to that of cones whereas the corresponding amplification in horizontal cells was about 6×. Differences in the growth of contrast gain with the intensity of the background illumination for cones versus bipolar cells suggest that there are at least two adaptation-dependent mechanisms regulating contrast gain. One is evident in the cone photoresponse such that an approximately linear relation holds between the steady-state hyperpolarization and contrast gain. The other arises between the voltage responses of the cones and bipolar cells. It could be presynaptic (modulation of cone transmitter release by horizontal cell feedback or other mechanisms) and/or postsynaptic, that is, intrinsic to bipolar cells. Contrast gain grew with the background intensity by a larger factor in horizontal than in bipolar cells. This provides a basis for the widely held view that light adaptation increases the strength of surround antagonism in bipolar cells. On average, the effects of light adaptation and most quantitative indices of contrast processing were remarkably similar for Bd and Bh cells, implying that both classes of bipolar cells, despite possible differences in underlying mechanisms, are about equally capable of encoding all primary aspects of contrast at all levels of light adaptation.

Spectral sensitivity of the feedback signal from horizontal cells to cones in goldfish retina

1998 ◽  
Vol 15 (5) ◽  
pp. 799-808 ◽  
Author(s):  
D.A. KRAAIJ ◽  
M. KAMERMANS ◽  
H. SPEKREIJSE
Keyword(s):  
Spectral Sensitivity ◽  
Horizontal Cell ◽  
Horizontal Cells ◽  
Feedback Signal ◽  
Cell Systems ◽  
Long Wavelength ◽  
Cell Recording ◽  
Cone System ◽  
Goldfish Retina ◽  
Uv Range

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 horizontal cell systems receive input from more than one cone system.

The interplexiform cell system II. Effects of dopamine on goldfish retinal neurones

1978 ◽  
Vol 201 (1142) ◽  
pp. 27-55 ◽  
Keyword(s):  
Horizontal Cell ◽  
Cell Activity ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Cell System ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Inner Plexiform Layer ◽  
Specific Effects ◽  
Β Blocker

The effects of atomized solutions of dopamine and certain related com­pounds have been tested on the intracellularly recorded activity of receptor, horizontal, bipolar and amacrine cells in the goldfish retina. Dopamine depolarizes the cone L-type horizontal cells and reduces the amplitude of light-evoked responses. These effects on L-type horizontal cells are completely abolished by the α-adrenergie blocker, phentolamine, but only partially depressed by the β-blocker, propanolol. L-Dopa, noradrenalin, and serotonin do not have effects on L-type horizontal cells when applied at concentrations similar to those that cause maximal dopamine effects. The results suggest that the effects of dopamine on L-type horizontal cells are specific, and we propose that they mimic the effects of interplexiform cell activity. Dopamine has no effects on rod horizontal cells in goldfish and variable effects on C-type horizontal cells. On bipolar cells, dopamine alters the dark membrane potential, enhances the central response to light, and depresses the surround response. Dopamine also decreases the horizontal cell feedback evident in cone responses. Finally, dopamine strongly depolarizes the transient type of amacrine cells, but it has no significant effect on the sustained type of amacrine cells. Assuming that dopamine is the transmitter of interplexiform cells, we suggest that these neurons regulate lateral inhibitory effects mediated by L-type horizontal cells in the outer plexiform layer and transient amacrine cells in the inner plexiform layer. In addition, it appears as if interplexiform cells have specific effects on bipolar cells and are capable of regulating centre-surround antagonism in these cells. The net effect of interplexiform cell activity is to isolate the bipolars from the influence of the surround.

scholarly journals The kinetics of tracer movement through homologous gap junctions in the rabbit retina

1998 ◽  
Vol 15 (4) ◽  
pp. 765-777 ◽  
Author(s):  
STEPHEN L. MILLS ◽  
STEPHEN C. MASSEY
Keyword(s):  
Gap Junctions ◽  
Dynamic Range ◽  
Horizontal Cell ◽  
Cell Types ◽  
Horizontal Cells ◽  
Rabbit Retina ◽  
Tracer Movement ◽  
Electrode Resistance ◽  
Coupled Cells ◽  
Kinetics Of

Observation of the spread of biotinylated or fluorescent tracers following injection into a single cell has become one of the most common methods of demonstrating the presence of gap junctions. Nevertheless, many of the fundamental features of tracer movement through gap junctions are still poorly understood. These include the relative roles of diffusion and iontophoretic current, and under what conditions the size of the stained mosaic will increase, asymptote, or decline. Additionally, the effect of variations in amount of tracer introduced, as produced by variation in electrode resistance following cell penetration, is not obvious. To examine these questions, Neurobiotin was microinjected into the two types of horizontal cell of the rabbit retina and visualized with streptavidin-Cy3. Images were digitally captured using a confocal microscope. The spatial distribution of Neurobiotin across the patches of coupled cells was measured. Adequate fits to the data were obtained by fitting to a model with terms for diffusion and amount of tracer injected. Results indicated that passive diffusion is the major source of tracer movement through gap junctions, whereas iontophoretic current played no role over the range tested. Fluorescent visualization, although slightly less sensitive than peroxidase reactions, produced staining intensities with a more useful dynamic range. The rate constants for movement of Neurobiotin between A-type horizontal cells was about ten times greater than that for B-type horizontal cells. Although direct extrapolation to ion conductances cannot be assumed, tracer movement can be used to give an estimate of relative coupling rates across cell types, retinal location, or modulation conditions in intact tissue.

scholarly journals Robust syntaxin-4 immunoreactivity in mammalian horizontal cell processes

2007 ◽  
Vol 24 (4) ◽  
pp. 489-502 ◽  
Author(s):  
ARLENE A. HIRANO ◽  
JOHANN HELMUT BRANDSTÄTTER ◽  
ALEJANDRO VILA ◽  
NICHOLAS C. BRECHA
Keyword(s):  
Horizontal Cell ◽  
Plexiform Layer ◽  
Horizontal Cells ◽  
Snare Proteins ◽  
Double Labeling ◽  
Subcellular Compartment ◽  
Feedback Communication ◽  
Syntaxin 4 ◽  
Molecular Machinery ◽  
Cell Processes

Horizontal cells mediate inhibitory feed-forward and feedback communication in the outer retina; however, mechanisms that underlie transmitter release from mammalian horizontal cells are poorly understood. Toward determining whether the molecular machinery for exocytosis is present in horizontal cells, we investigated the localization of syntaxin-4, a SNARE protein involved in targeting vesicles to the plasma membrane, in mouse, rat, and rabbit retinae using immunocytochemistry. We report robust expression of syntaxin-4 in the outer plexiform layer of all three species. Syntaxin-4 occurred in processes and tips of horizontal cells, with regularly spaced, thicker sandwich-like structures along the processes. Double labeling with syntaxin-4 and calbindin antibodies, a horizontal cell marker, demonstrated syntaxin-4 localization to horizontal cell processes; whereas, double labeling with PKC antibodies, a rod bipolar cell (RBC) marker, showed a lack of co-localization, with syntaxin-4 immunolabeling occurring just distal to RBC dendritic tips. Syntaxin-4 immunolabeling occurred within VGLUT-1-immunoreactive photoreceptor terminals and underneath synaptic ribbons, labeled by CtBP2/RIBEYE antibodies, consistent with localization in invaginating horizontal cell tips at photoreceptor triad synapses. Vertical sections of retina immunostained for syntaxin-4 and peanut agglutinin (PNA) established that the prominent patches of syntaxin-4 immunoreactivity were adjacent to the base of cone pedicles. Horizontal sections through the OPL indicate a one-to-one co-localization of syntaxin-4 densities at likely all cone pedicles, with syntaxin-4 immunoreactivity interdigitating with PNA labeling. Pre-embedding immuno-electron microscopy confirmed the subcellular localization of syntaxin-4 labeling to lateral elements at both rod and cone triad synapses. Finally, co-localization with SNAP-25, a possible binding partner of syntaxin-4, indicated co-expression of these SNARE proteins in the same subcellular compartment of the horizontal cell. Taken together, the strong expression of these two SNARE proteins in the processes and endings of horizontal cells at rod and cone terminals suggests that horizontal cell axons and dendrites are likely sites of exocytotic activity.

Physiological and pharmacological analysis of suppressive rod-cone interaction in Necturus retina [corrected]

1989 ◽  
Vol 61 (4) ◽  
pp. 866-877 ◽  
Author(s):  
T. Eysteinsson ◽  
T. E. Frumkes
Keyword(s):  
Light Adaptation ◽  
Horizontal Cell ◽  
Red Light ◽  
Background Field ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Lead Chloride ◽  
Inhibitory Influence ◽  
Third Order ◽  
Small Spot

1. Intracellular recordings were obtained from retinal neurons of the mudpuppy, Necturus, while superfusing the eyecup with various pharmacologic agents. In most experiments, the retina was continuously stimulated with a small spot of red light that was centered over the recording electrode and flickering at rates too fast for amphibian rods to follow. The retina was additionally stimulated intermittently with a dim, spatially diffuse background field of 520 nm wavelength. 2. In general, the dim background greatly enhanced flicker responsiveness. We (16) previously called this effect suppressive rod-cone interaction (SRCI) and showed it reflects a tonic suppressive influence on cone pathways that is removed by selective rod-light adaptation. 3. Lead chloride has been claimed to selectively block rod-related retinal responses (13, 35). While recording from horizontal cells lead chloride decreases responses to the dim, diffuse light flashes, enhances the frequency entrained response attributable to cones, and eliminates a background influence on flicker responses. 4. O-phospho-D-serine (DOP), kynurenic acid (KyA), and piperidine dicarboxylic acid are known to act on horizontal cells as antagonists of the photoreceptor neurotransmitter (26, 32, 33). In both depolarizing and hyperpolarizing bipolar cells, these agents enhance flicker responsiveness with no background present and prevent background enhancement of flicker. 5. Mudpuppy cones were found to have a receptive-field surround, which under our stimulus conditions is attributable to rod input. KyA, which is unknown to have any direct influence on photoreceptors, totally blocks this surround mechanism. This indicates that the cone-surround mechanism is attributable to horizontal cell feedback. The influence of KyA on SRCI in cones is similar to that observed in recordings from depolarizing bipolar cells. 6. Most sustained third-order neurons demonstrate SRCI. In these cells, SRCI is blocked by DOP or KyA. Most ON-OFF neurons fail to demonstrate SRCI under control circumstances. The ON-response of these cells is blocked by 2-amino-4-phosphonobutyric acid (31) which leaves the OFF-response intact. While their ON-response is blocked, ON-OFF neurons demonstrate SRCI. 7. The foregoing results indicate that SRCI reflects a tonic, inhibitory influence of horizontal cells on cone pathways that is removed by light-adapting rods. In part, SRCI must involve horizontal cell feedback onto cones. SRCI in third-order neurons appears to largely reflect distal retinal processing.

Cone connections of the horizontal cells of the rhesus monkey’s retina

1987 ◽  
Vol 229 (1257) ◽  
pp. 345-379 ◽  
Keyword(s):  
Gap Junctions ◽  
Horizontal Cell ◽  
Plexiform Layer ◽  
Basic Feature ◽  
Morphological Type ◽  
Horizontal Cells ◽  
Cell Contact ◽  
H1 Cells ◽  
Dendritic Fields ◽  
Relative Differences

The presence in the rhesus monkey’s retina of a second morphological type of horizontal cell (H2), described by Kolb et al . (1980), is confirmed. Both types of cell are here further described. Their cone connections are quantified and compared with those of mammals and other vertebrates. The dendrites and axons of the H2 type of cell contact only cones as do the dendrites of the H1 cell (originally described by Polyak (1941)) which has an axon contacting only rods. The dendrites of foveal H2 cells contact between 11 and 14 cones; those of H1 contact 7. The number of cones that each type of cell contacts increases with increasing distance from the fovea, so that, by 5-6 mm eccentricity, H2-type cells synapse with between 20 and 30 cones, and the H1 cells with 12-15. The qualitatively estimated coverage factors of each are 3 or 4; every cone synapses with more than one of both types. Neither type of horizontal cell makes chromatically specific connections that are anatomically recognizable, unlike the situation in some teleostean and turtle retinae. Individual horizontal cells, particularly those connected to foveal cones, may have different ratios of chromatic input. At equivalent eccentricities, up to about 6 mm from the fovea, the dendritic fields of H2 horizontal cells are about twice the size of H1 cells and contact about twice the number of cones. These relative differences are closely similar to those of the cat’s horizontal cells and it is suggested that they are a basic feature of most placental mammals. The organization of foveal cone fibres within Henle’s layer is described. The distribution of primate cone telodendria, gap junctions and synapses in the outer plexiform layer are briefly reviewed and compared with those of other vertebrate retinae.

scholarly journals Paradoxical enhancement of chemoreceptor detection sensitivity by a sensory adaptation enzyme

2017 ◽  
Vol 114 (36) ◽  
pp. E7583-E7591 ◽  
Author(s):  
Run-Zhi Lai ◽  
Xue-Sheng Han ◽  
Frederick W. Dahlquist ◽  
John S. Parkinson
Keyword(s):  
Catalytic Activity ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Covalent Modification ◽  
Detection Sensitivity ◽  
Enhancement Effect ◽  
Sensory Adaptation ◽  
Binding Interaction ◽  
Chemical Gradients ◽  
Response Enhancement

A sensory adaptation system that tunes chemoreceptor sensitivity enables motileEscherichia colicells to track chemical gradients with high sensitivity over a wide dynamic range. Sensory adaptation involves feedback control of covalent receptor modifications by two enzymes: CheR, a methyltransferase, and CheB, a methylesterase. This study describes a CheR function that opposes the signaling consequences of its catalytic activity. In the presence of CheR, a variety of mutant serine chemoreceptors displayed up to 40-fold enhanced detection sensitivity to chemoeffector stimuli. This response enhancement effect did not require the known catalytic activity of CheR, but did involve a binding interaction between CheR and receptor molecules. Response enhancement was maximal at low CheR:receptor stoichiometry and quantitative analyses argued against a reversible binding interaction that simply shifts the ON–OFF equilibrium of receptor signaling complexes. Rather, a short-lived CheR binding interaction appears to promote a long-lasting change in receptor molecules, either a covalent modification or conformation that enhances their response to attractant ligands.

Effects of light stimuli on the release of dopamine from interplexiform cells in the white perch retina

1991 ◽  
Vol 7 (5) ◽  
pp. 451-458 ◽  
Author(s):  
Osamu Umino ◽  
Yunhee Lee ◽  
John E. Dowling
Keyword(s):  
Receptive Field ◽  
White Perch ◽  
Horizontal Cell ◽  
Receptive Fields ◽  
Plexiform Layer ◽  
Horizontal Cells ◽  
Field Size ◽  
Dopamine Antagonists ◽  
Flickering Light ◽  
Receptive Field Size

AbstractInterplexiform cells are centrifugal neurons in the retina carrying information from the inner to the outer plexiform layers. In teleost fish, interplexiform cells appear to release dopamine in the outer plexiform layer after prolonged darkness that modulates the receptive-field size and light responsiveness of horizontal cells (Mangel & Dowling, 1985; Yang et al., 1988a, b). It has been proposed that interplexiform cells may also release dopamine upon steady illumination because horizontal cells' receptive fields shrink in the light (Shigematsu & Yamada, 1988). Here, we report the shrinkage of the receptive fields of horizontal cells seen in the presence of background illumination is not blocked by dopamine antagonists, indicating that dopamine does not underlie the receptive-field size changes observed during steady illumination. Flickering light, however, does appear to stimulate the release of dopamine from the interplexiform cells, resulting in a marked reduction of horizontal cell receptive-field size. Taken together, experiments on horizontal cells indicate that dopamine is released from interplexiform cells in the teleost retina after prolonged darkness and during flickering light, but that dopamine release from interplexiform cells during steady retinal illumination is minimal.

Synaptic connexions made by horizontal cells within the outer plexiform layer of the retina of the cat and the rabbit

1974 ◽  
Vol 186 (1085) ◽  
pp. 317-331 ◽  
Keyword(s):  
Horizontal Cell ◽  
Plexiform Layer ◽  
Cell Types ◽  
Bipolar Cells ◽  
Outer Plexiform Layer ◽  
Horizontal Cells ◽  
Chemical Synapses

Two ultrastructurally distinctive types of horizontal cells are described in the retinae of the cat and the rabbit. Evidence is presented that they have different synaptic connexions in the outer plexiform layer. The majority of the presynaptic structures identified in the outer plexiform layer of the rabbit (as defined on page 320) belong to a neurofilamentous type of horizontal cell. It is suggested that the cat may be the same. No synapses have been identified on to, or from, the second, predominantly neurotubular, type of horizontal cell. No chemical synapses on to, or between, horizontal cells have been found. Thus input of this kind to both types of horizontal cells is as yet only known to be from the photoreceptors. All positively identified postsynaptic processes were the dendrites or perikarya of bipolar cells. Other cell types that are possibly pre- or postsynaptic in the outer plexiform layer are discussed.

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