Color-opponent responses of small and giant bipolar cells in the carp retina

2000 ◽  
Vol 17 (4) ◽  
pp. 609-621 ◽  
Author(s):  
KIYOSHI SHIMBO ◽  
JUN-ICHI TOYODA ◽  
HIROAKI KONDO ◽  
TORU KUJIRAOKA
Keyword(s):  
Receptive Field ◽  
Spectral Characteristic ◽  
Short Wavelength ◽  
Opposite Polarity ◽  
Bipolar Cells ◽  
Morphological Properties ◽  
Long Wavelength ◽  
Green Spot ◽  
Ionic Mechanisms ◽  
Receptive Field Center

The physiological and morphological properties of color-opponent bipolar cells in the carp retina were studied. Fifty nine OFF-center bipolar cells and 63 ON-center bipolar cells out of about 500 total bipolar cells recorded showed color-opponent responses. The OFF-center color-opponent bipolar cells were classified into three subgroups according to their spectral and spatial responses. Fifty OFF-center color-opponent cells responded with depolarization to a blue light spot and with hyperpolarization to a red spot in the receptive-field center. The polarity of the surround response was opposite to that of center response at each wavelength. Therefore these cells were classified as OFF double-opponent cells (OFF-DO). Eight cells responded with hyperpolarization to a blue and green spot and with depolarization to a red spot. The surround responses of those cells were depolarizing at any wavelength (R+G− cell). One responded with hyperpolarization to a blue and red spot and with depolarization to a green spot. The surround response showed a different spectral characteristic from that of the center response. It responded with depolarization to a blue and green annulus and with hyperpolarization to a red annulus (R−G+B− cell). The ON-center color-opponent bipolar cells were similarly classified into three subgroups. Sixty of ON-center color-opponent cells were the double color-opponent type (ON-DO cell), showing the responses of opposite polarity to the OFF-DO cells. Two cells were classified as R−G+ cell, and one cell as R+G−B+ cell. Both OFF- and ON-DO cells were identified by their morphology as Cajal's giant bipolar cells, and R+G−, R−G+, R−G+B−, and R+G−B+ cells as Cajal's small bipolar cells. The analysis of the latency and the ionic mechanisms of their responses suggest that DO cells under light-adapted conditions receive direct inputs from long-wavelength (red) cones, RG cells from middle-wavelength (green) cones, and RGB cells from short-wavelength (blue) cones. Possible mechanisms of the opponent inputs to these bipolar cells are discussed.

scholarly journals Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. II. Studies on responses evoked by transretinal current stimulation.

1983 ◽  
Vol 81 (4) ◽  
pp. 603-612 ◽  
Author(s):  
A Kaneko ◽  
T Saito
Keyword(s):  
Reversal Potential ◽  
Bipolar Cells ◽  
Synaptic Delay ◽  
Evoked Responses ◽  
Sodium Permeability ◽  
Current Pulses ◽  
Ionic Mechanisms ◽  
Permeability Increase ◽  
Receptive Field Center

Transretinal current pulses flowing from the receptor side to the vitreous side of the retina cause transient release of transmitter from the photoreceptor terminals, and in off-center bipolar cells they evoke transient depolarizations with a brief (less than 1 ms) synaptic delay. Since it is known that the presence of Na+ in the external medium is not essential for this type of transmitter release, we used this procedure to examine the role of [Na+]o in the generation of light-evoked responses (hyperpolarizing to spot illumination in the receptive field center and depolarizing to an annulus in the surround) of this type of bipolar cell. When the cell membrane was steadily depolarized by current injection through the recording microelectrode, the depolarizing response evoked by the transretinal current pulses decreased in amplitude and reversed its polarity at above +45 mV. Conversely, the response amplitude increased when the cell was steadily hyperpolarized. The reversal potential seems to be lowered in low [Na+]o (28 mM). Removal of Na+ from the superfusate hyperpolarized the cell and both the light-evoked and current-evoked responses disappeared. From these observations, it is hypothesized that the hyperpolarizing center response of the off-center bipolar cells is a result of removal of sustained depolarization produced by sodium permeability increase.

scholarly journals Ionic mechanisms underlying the responses of off-center bipolar cells in the carp retina. I. Studies on responses evoked by light.

1983 ◽  
Vol 81 (4) ◽  
pp. 589-601 ◽  
Author(s):  
T Saito ◽  
A Kaneko
Keyword(s):  
Reversal Potential ◽  
Input Resistance ◽  
Bipolar Cells ◽  
Inward Rectification ◽  
Current Voltage ◽  
Ionic Mechanisms ◽  
Resistance Decrease ◽  
Relationship Of ◽  
Current Voltage Relationship ◽  
Receptive Field Center

Off-center bipolar cells show hyperpolarizing responses to spot illumination in the receptive field center and depolarization responses to an annulus in the surround. To understand the ionic mechanisms underlying these responses, we examined the current-voltage relationship of these bipolar cells, input resistance changes during their light-evoked responses, and the reversal potentials of these responses. Off-center bipolar cells generally showed inward rectification when they were hyperpolarized and outward rectification when they were strongly depolarized. The membrane potential at which the I-V relationship deviated from linearity varied in individual cells. Hyperpolarizing center responses were generally accompanied by a resistance increase, irrespective of signal inputs either from red-sensitive cones or from rods, and the response polarities reversed at greater than +50 mV. Depolarizing surround responses were accompanied by a resistance decrease with a reversal potential at about +28 mV (one case). From the above observations, it is suggested that the center responses are generated by a decrease in sodium conductance (gNa) and the surround response is generated by an increase in gNa.

scholarly journals Nonlinearities in retinal bipolar cells shape the encoding of artificial and natural stimuli

2020 ◽  
Author(s):  
Helene Marianne Schreyer ◽  
Tim Gollisch
Keyword(s):  
Receptive Field ◽  
Bipolar Cells ◽  
Spatial Integration ◽  
Nonlinear Properties ◽  
Natural Stimuli ◽  
Cell Type Specific ◽  
Linear Signal ◽  
Parallel Feature ◽  
Nonlinear Signal ◽  
Receptive Field Center

AbstractThe retina dissects the visual scene into parallel feature channels, and bipolar cells are speculated to play a key role in this signal separation. Yet, bipolar cells are traditionally viewed as simple, linear neurons. Here, using the salamander retina, we investigated the hypothesis of linear signal processing in bipolar cells by intracellularly recording their voltage signals under artificial and natural visual stimuli. We observed nonlinear representation of contrast and, unexpectedly, also nonlinear spatial integration in a sizable fraction of bipolar cells. Furthermore, linear receptive field models fail to describe responses of nonlinear bipolar cells to spatially structured artificial and natural stimuli. The nonlinear properties occur in the receptive field center and may be cell-type specific, with stronger effects in transient than sustained bipolar cells. Thus, our data suggest that nonlinear signal pooling starts earlier than previously thought, that is, before signal integration in bipolar cells.

scholarly journals Short-wavelength cone-opponent retinal ganglion cells in mammals

2014 ◽  
Vol 31 (2) ◽  
pp. 165-175 ◽  
Author(s):  
DAVID W. MARSHAK ◽  
STEPHEN L. MILLS
Keyword(s):  
Retinal Ganglion Cells ◽  
Short Wavelength ◽  
Ganglion Cells ◽  
Mammalian Species ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Opposite Polarity ◽  
Bipolar Cells ◽  
Retinal Ganglion ◽  
Cone Bipolar Cells

AbstractIn all of the mammalian species studied to date, the short-wavelength-sensitive (S) cones and the S-cone bipolar cells that receive their input are very similar, but the retinal ganglion cells that receive synapses from the S-cone bipolar cells appear to be quite different. Here, we review the literature on mammalian retinal ganglion cells that respond selectively to stimulation of S-cones and respond with opposite polarity to longer wavelength stimuli. There are at least three basic mechanisms to generate these color-opponent responses, including: (1) opponency is generated in the outer plexiform layer by horizontal cells and is conveyed to the ganglion cells via S-cone bipolar cells, (2) inputs from bipolar cells with different cone inputs and opposite response polarity converge directly on the ganglion cells, and (3) inputs from S-cone bipolar cells are inverted by S-cone amacrine cells. These are not mutually exclusive; some mammalian ganglion cells that respond selectively to S-cone stimulation seem to utilize at least two of them. Based on these findings, we suggest that the small bistratified ganglion cells described in primates are not the ancestral type, as proposed previously. Instead, the known types of ganglion cells in this pathway evolved from monostratified ancestral types and became bistratified in some mammalian lineages.

Comparison of the responses of AII amacrine cells in the dark- and light-adapted rabbit retina

1999 ◽  
Vol 16 (4) ◽  
pp. 653-665 ◽  
Author(s):  
DAIYAN XIN ◽  
STEWART A. BLOOMFIELD
Keyword(s):  
Receptive Field ◽  
Light Adaptation ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Rabbit Retina ◽  
Response Component ◽  
Synaptic Inputs ◽  
Field Organization ◽  
Receptive Field Organization ◽  
Aii Amacrine Cells

We studied the light-evoked responses of AII amacrine cells in the rabbit retina under dark- and light-adapted conditions. In contrast to the results of previous studies, we found that AII cells display robust responses to light over a 6–7 log unit intensity range, well beyond the operating range of rod photoreceptors. Under dark adaptation, AII cells showed an ON-center/OFF-surround receptive-field organization. The intensity–response profile of the center-mediated response component followed a dual-limbed sigmoidal function indicating a transition from rod to cone mediation as stimulus intensities were increased. Following light adaptation, the receptive-field organization of AII cells changed dramatically. Light-adapted AII cells showed both ON- and OFF-responses to stimulation of the center receptive field, but we found no evidence for an antagonistic surround. Interestingly, the OFF-center response appeared first following rapid light adaptation and was then replaced gradually over a 1–4 min period by the emerging ON-center response component. Application of the metabotropic glutamate receptor agonist APB, the ionotropic glutamate blocker CNQX, 8-bromo-cGMP, and the nitric oxide donor SNAP all showed differential effects on the various center-mediated responses displayed by dark- and light-adapted AII cells. Taken together, these pharmacological results indicated that different synaptic circuits are responsible for the generation of the different AII cell responses. Specifically, the rod-driven ON-center responses are apparently derived from rod bipolar cell synaptic inputs, whereas the cone-driven ON-center responses arise from signals crossing the gap junctions between AII cells and ON-center cone bipolar cells. Additionally, the OFF-center response of light-adapted AII cells reflects direct synaptic inputs from OFF-center cone bipolar cells to AII dendritic processes in the distal inner plexiform layer.

Receptive field of the retinal bipolar cell: a pharmacological study in the tiger salamander

1996 ◽  
Vol 76 (3) ◽  
pp. 2005-2019 ◽  
Author(s):  
W. A. Hare ◽  
W. G. Owen
Keyword(s):  
Receptive Field ◽  
Gaba Receptors ◽  
Bipolar Cell ◽  
Horizontal Cell ◽  
Pharmacological Study ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Gaba Uptake ◽  
Gamma Aminobutyric Acid ◽  
Gabaergic Synapse

1. It is widely believed that signals contributing to the receptive field surrounds of retinal bipolar cells pass from horizontal cells to bipolar cells via GABAergic synapses. To test this notion, we applied gamma-aminobutyric acid (GABA) agonists and antagonists to isolated, perfused retinas of the salamander Ambystoma tigrinum while recording intracellularly from bipolar cells, horizontal cells, and photoreceptors. 2. As we previously reported, administration of the GABA analogue D-aminovaleric acid in concert with picrotoxin did not block horizontal cell responses or the center responses of bipolar cells but blocked the surround responses of both on-center and off-center bipolar cells. 3. Surround responses were not blocked by the GABA, antagonists picrotoxin or bicuculline, the GABAB agonist baclofen or the GABAB antagonist phaclofen, and the GABAC antagonists picrotoxin or cis-4-aminocrotonic acid. Combinations of these drugs were similarly ineffective. 4. GABA itself activated a powerful GABA uptake mechanism in horizontal cells for which nipecotic acid is a competitive agonist. It also activated, both in horizontal cells and bipolar cells, large GABAA conductances that shunted light responses but that could be blocked by picrotoxin or bicuculline. 5. GABA, administered together with picrotoxin to block the shunting effect of GABAA activation, did not eliminate bipolar cell surround responses at concentrations sufficient to saturate the known types of GABA receptors. 6. Surround responses were not blocked by glycine or its antagonist strychnine, or by combinations of drugs designed to eliminate GABAergic and glycinergic pathways simultaneously. 7. Although we cannot fully discount the involvement of a novel GABAergic synapse, the simplest explanation of our findings is that the primary pathway mediating the bipolar cell's surround is neither GABAergic nor glycinergic.

Dynamic Properties of Recurrent Inhibition in Primary Visual Cortex: Contrast and Orientation Dependence of Contextual Effects

2000 ◽  
Vol 83 (2) ◽  
pp. 1019-1030 ◽  
Author(s):  
Valentin Dragoi ◽  
Mriganka Sur
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Primary Visual Cortex ◽  
Dynamic Properties ◽  
Orientation Dependence ◽  
Recurrent Inhibition ◽  
Inhibitory Neurons ◽  
Classical Receptive Field ◽  
Contextual Interactions ◽  
Receptive Field Center

A fundamental feature of neural circuitry in the primary visual cortex (V1) is the existence of recurrent excitatory connections between spiny neurons, recurrent inhibitory connections between smooth neurons, and local connections between excitatory and inhibitory neurons. We modeled the dynamic behavior of intermixed excitatory and inhibitory populations of cells in V1 that receive input from the classical receptive field (the receptive field center) through feedforward thalamocortical afferents, as well as input from outside the classical receptive field (the receptive field surround) via long-range intracortical connections. A counterintuitive result is that the response of oriented cells can be facilitated beyond optimal levels when the surround stimulus is cross-oriented with respect to the center and suppressed when the surround stimulus is iso-oriented. This effect is primarily due to changes in recurrent inhibition within a local circuit. Cross-oriented surround stimulation leads to a reduction of presynaptic inhibition and a supraoptimal response, whereas iso-oriented surround stimulation has the opposite effect. This mechanism is used to explain the orientation and contrast dependence of contextual interactions in primary visual cortex: responses to a center stimulus can be both strongly suppressed and supraoptimally facilitated as a function of surround orientation, and these effects diminish as stimulus contrast decreases.

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