Physiological and morphological properties of OFF- and ON-center bipolar cells in the Xenopus retina: Effects of glycine and GABA

1991 ◽  
Vol 7 (4) ◽  
pp. 363-376 ◽  
Author(s):  
Susan Stone ◽  
Michael Schutte
Keyword(s):  
Cell Response ◽  
Bipolar Cell ◽  
Lucifer Yellow ◽  
Bipolar Cells ◽  
Morphological Features ◽  
General Idea ◽  
Morphological Properties ◽  
Light Responses ◽  
On And Off Pathways

AbstractWe studied the morphology and center-surround organization of Lucifer Yellow injected OFF- and ON-center bipolar cells in the light-adapted Xenopus retina and the effects of glycine and GABA on their cone-mediated light responses. In both classes of cell, prominent antagonistic surround responses up to 20 mV in amplitude could be evoked without first suppressing the center responses with steady illumination. An additional feature of the light-evoked bipolar cell response was a pronounced (up to –24 mV) delayed hyperpolarizing after potential (DHAP) which followed the depolarizing responses of both classes of bipolar cell.The morphological features of dye-injected bipolar cells conformed to the general idea of segregation of ON and OFF pathways in the inner and outer interplexiform layer, however, the morphology of axonal arborizations was different for both classes. OFF-center cells ramified symmetrically around the primary branchpoint, whereas ON-center cells had a strongly asymmetrical arrangement of their axonal tree.The center and surround responses were differentially sensitive to glycine and GABA. Glycine eliminated the antagonistic surround responses in both OFF and ON cells; the center responses were reduced to some extent but were not eliminated. In contrast, GABA affected the hyperpolarizing responses much more strongly than the depolarizing response components. That is, the amplitude of the center response in the OFF cell and the surround response in the ON cell was reduced 80–90% during exposure to GABA, whereas the surround and center depolarizations of OFF and ON cells, respectively, were reduced only 0–10%.Our findings implicate a role for GABAergic and glycinergic pathways in the center-surround organization of bipolar cells in Xenopus retina. In addition, the results suggest that the pathways mediating center-surround antagonism may be different in OFF-bipolar cells vs. ON-bipolar cells.

scholarly journals Pharmacology of the skate electroretinogram indicates independent ON and OFF bipolar cell pathways.

1996 ◽  
Vol 107 (4) ◽  
pp. 535-544 ◽  
Author(s):  
R L Chappell ◽  
F J Rosenstein
Keyword(s):  
Bipolar Cell ◽  
Visual Information ◽  
Plexiform Layer ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Critical Feature ◽  
Single Class ◽  
Afferent Pathways ◽  
Afferent Information ◽  
On And Off Pathways

Organization of afferent information into parallel ON and OFF pathways is a critical feature of the vertebrate visual system. All afferent visual information in the vertebrate retina reaches the inner plexiform layer (IPL) via bipolar cells. It is at the bipolar cell level that separation of ON and OFF information first appears for afferent information from cones. This may also hold true for the rod pathway of cold-blooded vertebrates, but not for mammals. The all-rod retina of the skate presents an opportunity to examine such pathways in a retina having but a single class of photoreceptor. Immunocytochemical evidence suggests that both ON and OFF bipolar cells are present in the skate retina. We examined the pharmacology of the skate electroretinogram (ERG) to test the hypothesis that independent ON and OFF bipolar cell pathways are functional as rod afferent pathways from outer to inner plexiform layer in the skate. 100 microM 2-amino-4-phosphonobutyric acid (APB) reversibly blocked the skate ERG b-wave. A small d-wave-like OFF component of the ERG revealed by DC recording of response to a prolonged (10 s) flash of light was reduced or blocked by 5 mM kynurenic acid (KYN). We found that addition of 200 microM picrotoxin to the Ringer's solution revealed prominent ON and OFF components of the skate ERG while reducing the c-wave. These ON and OFF components were reversibly blocked by 100 microM APB and 5 mM KYN, respectively. Reversible block of the OFF component by KYN was also accomplished in the presence of 500 microM N-methyl-DL-aspartate. From these findings, we conclude that ON and OFF bipolar cells are likely to be functional as parallel afferent interplexiform pathways in the all-rod retina of the skate.

Structure of the receptive fields of bipolar cells in the salamander retina

1987 ◽  
Vol 58 (6) ◽  
pp. 1275-1291 ◽  
Author(s):  
S. Borges ◽  
M. Wilson
Keyword(s):  
Receptive Field ◽  
Bipolar Cell ◽  
Synaptic Connection ◽  
Lucifer Yellow ◽  
Receptive Fields ◽  
Bipolar Cells ◽  
Light Scatter ◽  
Small Spot ◽  
Dendritic Arbors ◽  
Rule Out

1. The receptive-field structure of bipolar cells in the salamander retina has been examined using isolated retinae from dark-adapted eyes. 2. Receptive-field mapping was carried out with a 25-microns diam spot of light whose wavelength and intensity was intended to stimulate rods rather than cones. 3. Both hyperpolarizing and depolarizing bipolar cells showed receptive fields having a single central point of maximum sensitivity from which sensitivity declined radially. Antagonistic surrounds could not be demonstrated using a small spot of light. 4. The diameter of receptive fields was found to vary between 374 and 662 micron, consistent with a single bipolar cell being effectively connected to 323-1,275 rods. 5. Lucifer yellow injections of bipolar cells revealed dendritic arbors whose greatest dimensions varied between 43 and 70 microns, consistent with a direct synaptic connection of between 10 and 24 rods to each bipolar cell. 6. We rule out signal spread within the rod network, extensive lateral ramification of rod process, nonlinearity of synaptic transmission, and light scatter, as possible explanations of large bipolar cell receptive fields. It seems likely, instead, that signals are extensively shared between bipolar cells.

scholarly journals VOLTAGE-GATED POTASSIUM CHANNELS CONTROL THE GAIN OF ROD-DRIVEN LIGHT RESPONSES IN MIXED-INPUT ON BIPOLAR CELLS

2020 ◽  
Author(s):  
Christina Joselevitch ◽  
Jan Klooster ◽  
Maarten Kamermans
Keyword(s):  
Potassium Channels ◽  
Bipolar Cell ◽  
Gain Control ◽  
Bipolar Cells ◽  
Transient Signal ◽  
List Type ◽  
Light Responses ◽  
Voltage Gated ◽  
Light Levels ◽  
Slow Kinetics

AbstractTo achieve high sensitivity at scotopic levels, vision sacrifices spatial and temporal resolution. The detection of dim light, however, depends crucially on the ability of the visual system to speed up rod signals as they advance towards the brain. At higher light levels, gain control mechanisms are necessary to prevent premature saturation of second-order neurons. We investigated how goldfish mixed-input ON bipolar cells (ON mBCs) manage to partially compensate for the intrinsically slow kinetics of rod signals in the dark-adapted state, and at the same time control the gain of rod signals. Rod-driven responses of axotomized ON mBCs become faster and more transient than those of rod horizontal cells as stimulus intensity increases. This transientness has a voltage-dependency consistent with the activation of a voltage-gated K+ conductance. Simulations with NEURON indicate that the voltage-gated K+ channels responsible for speeding up responses are concentrated at the distal tips of the bipolar cell dendrites, close to the glutamate receptors. These channels act as a gain control mechanism, by shunting the effect of tonically hyperpolarized rods onto the ON mBC. Further activation of K+ channels accelerates the ON mBC response by decreasing the membrane time constant as light levels increase. Therefore, the presence of voltage-gated K+ channels at the dendritic tips of ON mBCs extends the dynamic range of these neurons, and at the same time generates a transient signal already at the first visual synapse.Key Points SummaryHere we show that voltage-gated potassium channels can adjust the gain of the rod input to mixed-input ON bipolar cells and generate a transient signal already at the first visual synapse.These channels are activated during the light-induced depolarization, making bipolar cell light responses smaller, faster, and more transient, effects that can be abolished by the K+ channel blocker TEA.Mathematical simulations suggest that these channels are concentrated at the bipolar cell dendritic tips, close to the site of rod input.This kind of gain control happens at all levels in the retina and is especially important for cells that receive mixed input from rods and cones, in order to prevent premature saturation with increasing light levels and remove the temporal redundancy of the photoreceptor signal.

Single cell shape and population densities of indoleamine-accumulating and displaced bipolar cells in Reeves' turtle retina

1990 ◽  
Vol 238 (1293) ◽  
pp. 351-367 ◽  
Keyword(s):  
Cell Density ◽  
Bipolar Cell ◽  
Lucifer Yellow ◽  
Outer Nuclear Layer ◽  
Bipolar Cells ◽  
Cell Labelling ◽  
Specific Cell ◽  
Inner Plexiform Layer ◽  
Central Retina

Two types of bipolar cell in the Geoclemys reevesii retina were studied quantitatively by means of specific cell labelling with an indoleamine derivative (5, 6-dihydroxytryptamine, 5, 6-DHT), a nucleic acid stain (4, 6-diamidino-2-phenylindole, DAPI) and Lucifer yellow CH. Indoleamine-accumulating (IA ) bipolar cells were selectively labelled with 5, 6-DHT applied intraocularly. After the cells accumulated 5, 6-DHT, the indoleamine fluorescence was photoconverted to diaminobenzidine products to allow observation of morphological details. Close examination of many cells (cell number; n = 120) showed that the IA bipolar cells consist of a single morphological type whose axon collaterals ramify sublaminae 1, 4 and 5 respectively. This terminal branching pattern corresponds to cells that hyperpolarize when their receptive field centres are illuminated (Weiler 1981). The density of IA bipolar cells was highest in the visual streak (4130 cells mm -2 ) and lowest at the peripheral margin (1970 cells mm -2 ). By applying a small amount of DAPI to the eye, nuclei located in the most proximal row of the outer nuclear layer were labelled selectively. By using selective intracellular dye injection into DAPI-labelled cells under fluorescence microscope (Tauchi & Masland 1984, 1985), these cells were found to have Landolt’s clubs and single descending axons. Dye injections into more than fifty DAPI-labelled somata showed that they belonged exclusively to displaced bipolar cells. These comprised at least two subtypes that differ in the ramification pattern of their axon terminals within the inner plexiform layer: one was monostratified, whereas the other was bistratified. The displaced bipolar cell density was as high as 9400 cells mm -2 in the central retina, falling to 2000 cells mm -2 in the superior margin. In vitro Lucifer labelling revealed that the overall bipolar cell density in the central retina was as high as 39300 cells mm -2 . Both the conventionally located and displaced bipolar cells were included in this population. About 11% of the total bipolar cell population consisted of IA bipolar cells. Assuming that one half of the conventionally located bipolar cells are the centre-hyperpolarizing type, IA bipolar cells represent approximately 28% of the total. As displaced bipolar cells represent almost one quarter of the total bipolar population, the dislocation of their somata stands out morphologically, inviting investigation of possible functional correlates.

scholarly journals I4AA-Sensitive Chloride Current Contributes to the Center Light Responses of Bipolar Cells in the Tiger Salamander Retina

2000 ◽  
Vol 83 (6) ◽  
pp. 3473-3482 ◽  
Author(s):  
Fan Gao ◽  
Bruce R. Maple ◽  
Samuel M. Wu
Keyword(s):  
Receptor Antagonist ◽  
Bipolar Cell ◽  
Reversal Potential ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Chloride Current ◽  
Tiger Salamander ◽  
Light Responses ◽  
Chloride Currents ◽  
Axon Terminals

Light-evoked currents in depolarizing and hyperpolarizing bipolar cells (DBCs and HBCs) were recorded under voltage-clamp conditions in living retinal slices of the larval tiger salamander. Responses to illumination at the center of the DBCs' and HBCs' receptive fields were mediated by two postsynaptic currents: Δ I C, a glutamate-gated cation current with a reversal potential near 0 mV, and Δ I Cl, a chloride current with a reversal potential near −60 mV. In DBCs Δ I C was suppressed byl-2-amino-4-phosphonobutyric acid (l-AP4), and in HBCs it was suppressed by 6,7-dinitroquinoxaline-2,3-dione (DNQX). In both DBCs and HBCs Δ I Cl was suppressed by imidazole-4-acetic acid (I4AA), a GABA receptor agonist and GABAC receptor antagonist. In all DBCs and HBCs examined, 10 μM I4AA eliminated Δ I Cl and the light-evoked current became predominately mediated by Δ I C. The addition of 20 μM l-AP4 to the DBCs or 50 μM DNQX to HBCs completely abolished Δ I C. Focal application of glutamate at the inner plexiform layer elicited chloride currents in bipolar cells by depolarizing amacrine cells that release GABA at synapses on bipolar cell axon terminals, and such glutamate-induced chloride currents in DBCs and HBCs could be reversibly blocked by 10 μM I4AA. These experiments suggest that the light-evoked, I4AA-sensitive chloride currents (Δ I Cl) in DBCs and HBCs are mediated by narrow field GABAergic amacrine cells that activate GABACreceptors on bipolar cell axon terminals. Picrotoxin (200 μM) or (1,2,5,6-tetrahydropyridine-4yl) methyphosphinic acid (TPMPA) (2 other GABAC receptor antagonists) did not block (but enhanced and broadened) the light-evoked Δ I Cl, although they decreased the chloride current induced by puff application of GABA or glutamate. The light response of narrow field amacrine cells were not affected by I4AA, but were substantially enhanced and broadened by picrotoxin. These results suggest that there are at least two types of GABACreceptors in bipolar cells: one exhibits stronger I4AA sensitivity than the other, but both can be partially blocked by picrotoxin. The GABA receptors in narrow field amacrine cells are I4AA insensitive and picrotoxin sensitive. The light-evoked Δ I Cl in bipolar cells are mediated by the more strongly I4AA-sensitive GABAC receptors. Picrotoxin, although acting as a partial GABAC receptor antagonist in bipolar cells, does not suppress Δ I Clbecause its presynaptic effects on amacrine cell light responses override its antagonistic postsynaptic actions.

scholarly journals Characteristics of bipolar-bipolar coupling in the carp retina.

1988 ◽  
Vol 91 (2) ◽  
pp. 275-287 ◽  
Author(s):  
T Saito ◽  
T Kujiraoka
Keyword(s):  
Receptive Field ◽  
Bipolar Cell ◽  
Lucifer Yellow ◽  
Electrical Coupling ◽  
Coupling Efficiency ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Cell Types ◽  
Bipolar Cells ◽  
Cell Pair

ON and OFF bipolar cells were identified in the light-adapted carp retina by means of intracellular recording and Lucifer yellow dye injection. The receptive field centers, determined by measuring the response amplitudes obtained by centered spots of different diameters, were 0.3-1.0 mm for ON bipolar cells and 0.3-0.4 mm for OFF bipolar cells. These central receptive field values were much larger than the dendritic field diameters measured by histological methods. Simultaneous intracellular recordings were made from pairs of neighboring bipolar cells. Current of either polarity injected into one member of a bipolar cell pair elicited a sign-conserving, sustained potential change in the other bipolar cell. The coupling efficiency was nearly identical for both depolarizing and hyperpolarizing currents. The maximum separation of coupled bipolar cells was approximately 130 microns. This electrical coupling was reciprocal and summative, and it was observed in cell types of similar function and morphology. Dye coupling was observed in 4 out of 34 stained cells. These results strongly suggest that there is a spatial summation of signals at the level of bipolar cells, which makes their central receptive fields much larger than their dendritic fields.

The network properties of bipolar–bipolar cell coupling in the retina of teleost fishes

1994 ◽  
Vol 11 (3) ◽  
pp. 533-548 ◽  
Author(s):  
Osamu Umino ◽  
Michiyo Maehara ◽  
Soh Hidaka ◽  
Shigeo Kita ◽  
Yoko Hashimoto
Keyword(s):  
Bipolar Cell ◽  
Spatial Information ◽  
Lucifer Yellow ◽  
Light Stimulus ◽  
Early Stage ◽  
Electrical Coupling ◽  
Photoreceptor Cells ◽  
Significant Loss ◽  
Bipolar Cells ◽  
Cell Coupling

AbstractRetinal bipolar cells exhibit a center-surround antagonistic receptive field to a light stimulus (Werblin & Dowling, 1969; Kaneko, 1970), and thus constitute an early stage of spatial information processing. We injected Lucifer Yellow and a small biotinylated tracer, biocytin, into bipolar cells of the teleost retina to examine electrical coupling in these cells. Lucifer-Yellow coupling was observed in one of 55 stained bipolar cells; the coupling pattern was one injected bipolar cell and three surrounding cells. Biocytin coupling was observed in 16 of 55 stained bipolar cells, six of which were ON center and ten OFF center. Although biocytin usually coupled to three to six bipolar cells, some OFF-center bipolar cells showed strong coupling to more than 20 cells. The biocytin-coupled bipolar cells were morphologically homologous. Membrane appositions resembling gap junctions were found between dendrites and between axon terminals of neighboring bipolar cells.In the strongest biocytin-coupled bipolar cells, the contacts between bipolar cells and cone photoreceptor cells were examined after reconstruction of the dendritic trees of five well-stained, serially sectioned OFF-center bipolar cells. Each of these bipolar cells was in contact with different numbers of cones: 11 to 20 for twin cones and two to four for single cones. This implies that, although these bipolar cells belong to the same category, the signal inputs differ among bipolar cells. Numerical simulation conducted on a hexagonal array network model demonstrated that the electrical coupling of bipolar cells can decrease the difference in input (≈80%) without causing significant loss of spatial resolution. Our results suggest that electrical coupling of bipolar cells has the advantage of decreasing the dispersion of input signals from cones, and permits bipolar cells of the same class to respond to light with similar properties.

Reciprocal inhibition of voltage-gated potassium currents (IK(V)) by activation of cannabinoid CB1and dopamine D1receptors in ON bipolar cells of goldfish retina

2005 ◽  
Vol 22 (1) ◽  
pp. 55-63 ◽  
Author(s):  
SHIH-FANG FAN ◽  
STEPHEN YAZULLA
Keyword(s):  
G Protein ◽  
Receptor Agonist ◽  
Lucifer Yellow ◽  
Reciprocal Inhibition ◽  
Receptor Activation ◽  
Light Signal ◽  
Bipolar Cells ◽  
Protein G ◽  
Calcium Dependent ◽  
Voltage Dependent

Cannabinoid CB1receptor (viaGs) and dopamine D2receptor (viaGi/o) antagonistically modulate goldfish cone membrane currents. As ON bipolar cells have CB1and D1receptors, but not D2receptors, we focused on whether CB1receptor agonist and dopamine interact to modulate voltage-dependent outward membrane K+currentsIK(V)of the ON mixed rod/cone (Mb) bipolar cells. Whole-cell currents were recorded from Mb bipolar cells in goldfish retinal slices. Mb bipolar cells were identified by intracellular filling with Lucifer yellow. The bath solution was calcium-free and contained 1 mM cobalt to block indirect calcium-dependent effects. Dopamine (10 μM) consistently increasedIK(V)by a factor of 1.57 ± 0.12 (S.E.M.,n= 15). A CB receptor agonist, WIN 55212-2 (0.25–1 μM), had no effect, but 4 μM WIN 55212-2 suppressedIK(V)by 60%. IfIK(V)was first increased by 10 μM dopamine, application of WIN 55212-2 (0.25–1 μM) reversibly blocked the effect of dopamine even though these concentrations of WIN 55212-2 had no effect of their own. If WIN 55212-2 was applied first and dopamine (10 μM) was added to the WIN-containing solution, 0.1 μM WIN 55212-2 blocked the effect of dopamine. All effects of WIN 55212-2 were blocked by coapplication of SR 141716A (CB1antagonist) and pretreatment with pertussis toxin (blocker of Gi/o) indicating actionviaCB1receptor activation of G protein Gi/o. Coactivation of CB1and D1receptors on Mb bipolar cells produces reciprocal effects onIK(V). The CB1-evoked suppression ofIK(V)is mediated by G protein Gi/o, whereas the D1-evoked enhancement is mediated by G protein Gs. As dopamine is a retinal “light” signal, these data support our notion that endocannabinoids function as a “dark” signal, interacting with dopamine to set retinal sensitivity.

The rod bipolar cell of the mammalian retina

1991 ◽  
Vol 7 (1-2) ◽  
pp. 99-112 ◽  
Author(s):  
Heinz Wässle ◽  
Masayuki Yamashita ◽  
Ursula Greferath ◽  
Ulrike Grünert ◽  
Frank Müller
Keyword(s):  
Chloride Channels ◽  
Light Stimulus ◽  
Bipolar Cells ◽  
Immunocytochemical Staining ◽  
Nonselective Cation Channel ◽  
Light Responses ◽  
Kinase C ◽  
Mammalian Retina ◽  
Approaches To Study ◽  
Rod Bipolar Cells

AbstractThree approaches to study the function of mammalian rod bipolar cells are described. Extracellular recordings from the intact cat eye under light- and dark-adapted conditions showed that in dark-adapted retina all light responses can be blocked by 2-amino-4-phosphonobutyrate (APB). Immunocytochemical staining with an antibody against protein kinase C (PKC) labeled rod bipolar cells in all mammalian retinae tested. When rat retinae were dissociated, PKC immunoreactivity was also found in isolated bipolar cells and could be used for their identification as rod bipolars. Patch-clamp recordings were performed from such dissociated rod bipolar cells and their responses to APB were measured. APB closed a nonselective cation channel in the cell membrane. The actions of GABA and glycine were also tested and both opened chloride channels in dissociated rod bipolar cells. These results suggest that rod bipolar cells are depolarized by a light stimulus and that GABA as well as glycine modulate their light responses.

Sign in / Sign up

Export Citation Format

Share Document