Cone synapses with Golgi-stained bipolar cells that are morphologically similar to a center-hyperpolarizing and a center-depolarizing bipolar cell type in the turtle retina

1986 ◽  
Vol 250 (4) ◽  
pp. 510-520 ◽  
Author(s):  
Helga Kolb ◽  
Hou Hua Wang ◽  
Jill Jones
Keyword(s):  
Bipolar Cell ◽  
Bipolar Cells ◽  
Cell Type ◽  
Depolarizing Bipolar Cell

scholarly journals Cell Type-Selective Loss of Peroxisomal β-Oxidation Impairs Bipolar Cell but Not Photoreceptor Survival in the Retina

Cells ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 161
Author(s):  
Daniëlle Swinkels ◽  
Yannick Das ◽  
Sai Kocherlakota ◽  
Stefan Vinckier ◽  
Eric Wever ◽  
...  
Keyword(s):  
Bipolar Cell ◽  
Cell Types ◽  
Bipolar Cells ◽  
Cell Type ◽  
Peroxisomal Disorders ◽  
Multifunctional Protein ◽  
Ribbon Synapses ◽  
Different Cell Types ◽  
Oxidation Enzyme ◽  
Photoreceptor Death

Retinal degeneration is a common feature in peroxisomal disorders leading to blindness. Peroxisomes are present in the different cell types of the retina; however, their precise contribution to retinal integrity is still unclear. We previously showed that mice lacking the central peroxisomal β-oxidation enzyme, multifunctional protein 2 (MFP2), develop an early onset retinal decay including photoreceptor cell death. To decipher the function of peroxisomal β-oxidation in photoreceptors, we generated cell type selective Mfp2 knockout mice, using the Crx promotor targeting photoreceptors and bipolar cells. Surprisingly, Crx-Mfp2−/− mice maintained photoreceptor length and number until the age of 1 year. A negative electroretinogram was indicative of preserved photoreceptor phototransduction, but impaired downstream bipolar cell signaling from the age of 6 months. The photoreceptor ribbon synapse was affected, containing free-floating ribbons and vesicles with altered size and density. The bipolar cell interneurons sprouted into the ONL and died. Whereas docosahexaenoic acid levels were normal in the neural retina, levels of lipids containing very long chain polyunsaturated fatty acids were highly increased. Crx-Pex5−/− mice, in which all peroxisomal functions are inactivated in photoreceptors and bipolar cells, developed the same phenotype as Crx-Mfp2−/− mice. In conclusion, the early photoreceptor death in global Mfp2−/− mice is not driven cell autonomously. However, peroxisomal β-oxidation is essential for the integrity of photoreceptor ribbon synapses and of bipolar cells.

Retinal bipolar cell types differ in their inventory of ion channels

2006 ◽  
Vol 23 (2) ◽  
pp. 143-154 ◽  
Author(s):  
ELENA IVANOVA ◽  
FRANK MÜLLER
Keyword(s):  
Patch Clamp ◽  
Bipolar Cell ◽  
Cell Types ◽  
Bipolar Cells ◽  
Hcn Channels ◽  
Hcn Channel ◽  
Cell Type ◽  
Morphological Classification ◽  
Voltage Gated ◽  
Channel Currents

Bipolar cells were recorded in rat retinal slices to study the distribution of hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels. Patch-clamp whole cell measurements were combined with intracellular filling and recorded cells were morphologically identified. HCN channel isoforms HCN1-4 are differentially expressed in bipolar cells. Each bipolar cell type has a characteristic inventory of HCN channels. The combination of HCN channel currents and other voltage-gated currents can be used as a kind of “finger print” to electrophysiologically identify and classify bipolar cell types. Using this approach of combined electrophysiological and morphological classification we could identify a new ON-cone bipolar cell type.

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.

scholarly journals Synaptic vesicle dynamics in mouse rod bipolar cells

2008 ◽  
Vol 25 (4) ◽  
pp. 523-533 ◽  
Author(s):  
QUN-FANG WAN ◽  
ALEJANDRO VILA ◽  
ZHEN-YU ZHOU ◽  
RUTH HEIDELBERGER
Keyword(s):  
Synaptic Vesicle ◽  
Time Constant ◽  
Active Zone ◽  
Bipolar Cell ◽  
Visual Information ◽  
Membrane Surface ◽  
Bipolar Cells ◽  
Calcium Dependent ◽  
Vesicle Dynamics ◽  
Rod Bipolar Cells

AbstractTo better understand synaptic signaling at the mammalian rod bipolar cell terminal and pave the way for applying genetic approaches to the study of visual information processing in the mammalian retina, synaptic vesicle dynamics and intraterminal calcium were monitored in terminals of acutely isolated mouse rod bipolar cells and the number of ribbon-style active zones quantified. We identified a releasable pool, corresponding to a maximum of ≈35 vesicles/ribbon-style active zone. Following depletion, this pool was refilled with a time constant of ≈7 s. The presence of a smaller, rapidly releasing pool and a small, fast component of refilling was also suggested. Following calcium channel closure, membrane surface area was restored to baseline with a time constant that ranged from 2 to 21 s depending on the magnitude of the preceding Ca2+ transient. In addition, a brief, calcium-dependent delay often preceded the start of onset of membrane recovery. Thus, several aspects of synaptic vesicle dynamics appear to be conserved between rod-dominant bipolar cells of fish and mammalian rod bipolar cells. A major difference is that the number of vesicles available for release is significantly smaller in the mouse rod bipolar cell, both as a function of the total number per neuron and on a per active zone basis.

scholarly journals Diurnal Changes in Exocytosis and the Number of Synaptic Ribbons at Active Zones of an on-Type Bipolar Cell Terminal

2006 ◽  
Vol 96 (4) ◽  
pp. 2025-2033 ◽  
Author(s):  
Court Hull ◽  
Keith Studholme ◽  
Stephen Yazulla ◽  
Henrique von Gersdorff
Keyword(s):  
Synaptic Vesicle ◽  
Bipolar Cell ◽  
Bipolar Cells ◽  
Synaptic Ribbons ◽  
Diurnal Changes ◽  
Synaptic Vesicle Exocytosis ◽  
Pulse Ratio ◽  
Vesicle Exocytosis ◽  
Active Zones ◽  
Vesicle Pool

The number and morphology of synaptic ribbons at photoreceptor and bipolar cell terminals has been reported to change on a circadian cycle. Here we sought to determine whether this phenomenon exists at goldfish Mb-type bipolar cell terminals with the aim of exploring the role of ribbons in transmitter release. We examined the physiology and ultrastructure of this terminal around two time points: midday and midnight. Nystatin perforated-patch recordings of membrane capacitance ( Cm) revealed that synaptic vesicle exocytosis evoked by short depolarizations was reduced at night, even though Ca2+ currents were larger. The efficiency of exocytosis (measured as the Δ Cm jump per total Ca2+ charge influx) was thus significantly lower at night. The paired-pulse ratio remained unchanged, however, suggesting that release probability was not altered. Hence the decreased exocytosis likely reflects a smaller readily releasable vesicle pool at night. Electron microscopy of single sections from intact retinas averaged 65% fewer ribbons at night. Interestingly, the number of active zones did not change from day to night, only the probability of finding a ribbon at an active zone. Additionally, synaptic vesicle halos surrounding the ribbons were more completely filled at night when these on-type bipolar cells are more hyperpolarized. There was no change, however, in the physical dimensions of synaptic ribbons from day to night. These results suggest that the size of the readily releasable vesicle pool and the efficiency of exocytosis are reduced at night when fewer ribbons are present at bipolar cell terminal active zones.

Interaction of GABAB-Mediated Inhibition With Voltage-Gated Currents of Pyramidal Cells: Computational Mechanism of a Sensory Searchlight

1998 ◽  
Vol 80 (6) ◽  
pp. 3197-3213 ◽  
Author(s):  
Neil J. Berman ◽  
Leonard Maler
Keyword(s):  
Bipolar Cell ◽  
Excitatory Amino Acid ◽  
Maximum Amplitude ◽  
Pyramidal Cells ◽  
Inhibitory Effect ◽  
Bipolar Cells ◽  
Postsynaptic Potentials ◽  
Voltage Gated ◽  
Conditional Inhibition

Berman, Neil J. and Leonard Maler. Interaction of GABAB-mediated inhibition with voltage-gated currents of pyramidal cells: computational mechanism of a sensory searchlight. J. Neurophysiol. 80: 3197–3213, 1998. This study examines, in the in vitro electrosensory lateral line lobe (ELL) slice preparation, mono- and disynaptic inhibition in pyramidal cells evoked by stimulation of the direct descending pathway from nucleus praeminentialis (Pd). The pathway forms the stratum fibrosum (StF) in the ELL and consists of excitatory fibers from Pd stellate cells that make monosynaptic contact with pyramidal cells and disynaptic inhibitory contacts via local interneurons and of GABAergic inhibitory fibers from Pd bipolar cells. Single or tetanic stimulation (physiological rates of 100–200 Hz) of the StF produced excitatory postsynaptic potentials (EPSPs) or compound EPSPs in ELL pyramidal cells. Slow (>600 ms) and fast inhibitory postsynaptic potentials (IPSPs; 5–50 ms) also were evoked. Application of γ-aminobutyric acid-A (GABAA) antagonists blocked the fast inhibition and dramatically increased the firing rate response to StF tetanic stimuli. GABAA antagonists also increased the amplitude of the slow IPSP. The slow IPSP was reduced by GABAB antagonists. Blockade of excitatory amino acid (EAA) synaptic transmission allowed the monosynaptic bipolar-cell-mediated inhibition to be studied in isolation: EAA antagonists blocked most of the EPSP response to StF stimulation leaving fast and (an increased amplitude) slow IPSP components. The bipolar-cell IPSPs were mediated by GABAA and GABAB receptors as they were sensitive to GABAA and GABAB antagonists. The bipolar-cell IPSPs scaled with stimulation rate (20–400 Hz), reaching a maximum amplitude at 200 Hz. Inhibitory efficacy of bipolar-cell slow IPSPs were tested by their ability to reduce spiking in the face of sustained or brief current pulses. Established spike trains (by sustained injected current) were little affected by the onset of the slow IPSP. Weak brief currents injected during the slow IPSP were strongly inhibited. Strong brief currents could overcome the slow IPSP inhibitory effect. Inhibition was observed to interact with the intrinsic I A-like K+ currents to produce a complex control of cell spiking. Hyperpolarizing inhibition removes inactivation of I A to prevent subsequent inputs from driving the cell to threshold. Established depolarizing inputs, having allowed I A to inactivate, enable the cell to be highly sensitive to further depolarizing input. The term “conditional inhibition” is proposed to describe the general phenomenon where synaptic inhibition interacts with voltage-sensitive intrinsic currents.

scholarly journals A missense mutation in Grm6 reduces but does not eliminate mGluR6 expression or rod depolarizing bipolar cell function

2017 ◽  
Vol 118 (2) ◽  
pp. 845-854 ◽  
Author(s):  
Neal S. Peachey ◽  
Nazarul Hasan ◽  
Bernard FitzMaurice ◽  
Samantha Burrill ◽  
Gobinda Pangeni ◽  
...  
Keyword(s):  
Mouse Model ◽  
Missense Mutation ◽  
Mouse Models ◽  
Human Disease ◽  
Bipolar Cell ◽  
Night Blindness ◽  
Cell Function ◽  
Congenital Stationary Night Blindness ◽  
Depolarizing Bipolar Cell

This article describes a mouse model of the human disease complete congenital stationary night blindness in which the mutation reduces but does not eliminate GRM6 expression and bipolar cell function, a phenotype distinct from that seen in other Grm6 mouse models.

Different types of synapses with different spectral types of cones underlie color opponency in a bipolar cell of the turtle retina

1999 ◽  
Vol 16 (5) ◽  
pp. 801-809 ◽  
Author(s):  
SILKE HAVERKAMP ◽  
WOLFGANG MÖCKEL ◽  
JOSEF AMMERMÜLLER
Keyword(s):  
Bipolar Cell ◽  
Metabotropic Glutamate Receptors ◽  
Horizontal Cell ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Color Processing ◽  
Ionotropic Receptors ◽  
Metabotropic Glutamate ◽  
Different Types ◽  
Color Opponency

Electrophysiologically, color-opponent retinal bipolar cells respond with opposite polarities to stimulation with different wavelengths of light. The origin of these different polarities in the same bipolar cell has always been a mystery. Here we show that an intracellularly recorded and HRP-injected, red-ON, blue/green-OFF bipolar cell of the turtle retina made invaginating (ribbon associated) synapses exclusively with L-cones. Non-invaginating synapses resembling wide-cleft basal junctions were made exclusively with M-cones. Input from S-cones was not seen. From these results we suggest sign-inverting transmission from L-cones at invaginating synapses via metabotropic glutamate receptors, and sign-conserving transmission from M-cones at wide-cleft basal junctions via ionotropic receptors. To explain the pronounced blue sensitivity of the bipolar cell, computer simulations were performed using a sign-conserving input from a yellow/blue chromaticity-type (H3) horizontal cell. The response properties of the red-ON, blue/green-OFF bipolar cell could be quantitatively reproduced by this means. The simulation also explained the asymmetry in L- and M-cone inputs to the bipolar cell as found in the ultrastructural analysis and assigned a putative role to H3 horizontal cells in color processing in the turtle retina.

Sign in / Sign up

Export Citation Format

Share Document