Light-dependent plasticity of the synaptic terminals of Mb bipolar cells in goldfish retina

1992 ◽  
Vol 320 (4) ◽  
pp. 521-530 ◽  
Author(s):  
Stephen Yazulla ◽  
Keith M. Studholme
Keyword(s):  
Bipolar Cells ◽  
Dependent Plasticity ◽  
Synaptic Terminals ◽  
Goldfish Retina

GABAergic input to the synaptic terminals of mb1 bipolar cells in the goldfish retina

1987 ◽  
Vol 411 (2) ◽  
pp. 400-405 ◽  
Author(s):  
Stephen Yazulla ◽  
Keith M. Studholme ◽  
Jang-Yen Wu
Keyword(s):  
Bipolar Cells ◽  
Synaptic Terminals ◽  
Goldfish Retina

Cannabinoid receptors on goldfish retinal bipolar cells: Electron-microscope immunocytochemistry and whole-cell recordings

2000 ◽  
Vol 17 (3) ◽  
pp. 391-401 ◽  
Author(s):  
STEPHEN YAZULLA ◽  
KEITH M. STUDHOLME ◽  
HELEN H. McINTOSH ◽  
SHIH-FANG FAN
Keyword(s):  
Cannabinoid Receptors ◽  
Bipolar Cells ◽  
Delayed Rectifier ◽  
Double Labeling ◽  
Intense Staining ◽  
Whole Cell ◽  
Synaptic Terminals ◽  
Cell Recording ◽  
Whole Cell Recordings ◽  
Goldfish Retina

Cannabinoid CB1 receptors are distributed throughout the CNS and interact with GABA, glutamate, and dopamine systems. Cannabinoids have effects on the visual system, some of which may have a retinal component, particularly the enhancement of photosensitivity. We used immunocytochemistry and whole-cell recording to study cannabinoids in the goldfish retina. Immunoblots of an antiserum against amino acids (1-14) of the rat CB1 receptor produced a single band in goldfish retina at about 70 kDa. Light microscope immunocytochemistry of CB1 receptor immunoreactivity (CB1R-IR) revealed intense staining of Müller cells and weaker staining of ON bipolar cells (verified with double labeling with PKC-IR) and the outer and inner plexiform layers. Ultrastructural analysis revealed that CB1R-IR was localized intracellularly as well as on the plasma membrane of photoreceptor terminals, bipolar cell terminals and, rarely, amacrine cell boutons. Membrane-associated CB1R-IR was restricted to cone pedicles at sites removed from the synaptic ribbon. Regarding bipolar cells, membrane-associated CB1R-IR was found at 93% of the synaptic terminals in sublamina b (ON-type) and only at 33% of the synaptic terminals in sublamina a (OFF-type). Whole-cell recordings from large ON-type Mb bipolar cells showed that the delayed rectifier (IK(V)) was rapidly and reversibly inhibited by 1 μM of the cannabinoid agonists CP 54490 and (+)-WIN 55212-2, effects blocked completely by the antagonist SR 141716A (1 μM). Inhibition of IK(V) in the Mb bipolar cells by cannabinoids should result in a more tonic ON response to increments of light. As such, cannabinoids may play a role in modulating the temporal aspects of signaling in the retina.

scholarly journals Dihydropyridine-sensitive calcium current mediates neurotransmitter release from bipolar cells of the goldfish retina

1993 ◽  
Vol 13 (7) ◽  
pp. 2898-2909 ◽  
Author(s):  
M Tachibana ◽  
T Okada ◽  
T Arimura ◽  
K Kobayashi ◽  
M Piccolino
Keyword(s):  
Neurotransmitter Release ◽  
Calcium Current ◽  
Bipolar Cells ◽  
Goldfish Retina

Colour receptors, and their synaptic connexions, in the retina of a cyprinid fish

1975 ◽  
Vol 270 (902) ◽  
pp. 61-118 ◽  
Keyword(s):  
Bipolar Cell ◽  
Cell Types ◽  
Bipolar Cells ◽  
Synaptic Terminals ◽  
Cone Type ◽  
Cone Cells ◽  
Sparse Population ◽  
Microscopic Morphology ◽  
The Individual ◽  
Dendritic Fields

Morphologically speaking, there are five kinds of cone cells in the retina of the rudd ( Scardinius erythrophthalmus ). But two of them, the principal elements of the double cones and the free principal cones, are probably functionally equivalent, while another, sparse, population of small ( oblique ) cones (which disappear in older fish), is unlikely to make a significant contribution to visual spectral sensitivity. Thus, principal and accessory cones (usually paired with one another), and single cones seem to be the three receptors which underlie the fish’s trichromacy. Photographic densitometry of individual cone cells was used to provide evidence that accessory cones contain a green-absorbing photopigment and the single cones a blue one. Other arguments are given in support of those identifications, and they also strongly suggest that principal cones contain the red-absorbing pigment. Golgi-impregnated bipolar cells were examined electron-microscopically to determine the specific patterns of synaptic connexion they make with these different, anatomically identifiable, colour cones and with the retinal rods. Three principal arrangements were distinguished (see figure 69, page 190). (1) Rod bipolar cells comprise two distinct morphological types, both of which connect exclusively to principal (red) cones as well as to the rods within the outlines of their dendritic fields. (2) Selective cone bipolar cells, more delicate neurons with considerably wider dendritic fields, connect (according to type) to one or other of the different colour cone populations. Examples analysed were specific for the accessory (green) or for the single (blue) cones; no bipolar cells were found connected only to red cones. (3) Mixed cone bipolars have the smallest dendritic fields, and connect to combinations of cones (for example, red and green, or green and blue, but not red and blue). They also have synaptic input (usually relatively sparse) from the rods. Cells were encountered connecting to all three cone types, but they were only partially analysed, and are not described at length. The light microscopic morphology of these bipolar cell types consistently reflects the detailed pattern of connexion each makes with the different receptor populations (just as the morphology of the cones reflects the spectral properties of their photopigment). But while their synaptic connectivity is generally highly specific for cone type, they do occasionally make anomalous connexions with the ‘wrong’ receptors. There is a high degree of divergence (page 85) at the receptor-bipolar synapses, and the different kinds of cones each characteristically connect to different numbers of bipolar cells. Principal (red) cones, which are the most numerous, individually connect to more bipolars than cones of other types, whose characteristic synaptic divergence is likewise related to the frequency with which they occur in the retina. However, rods, which are much more numerous than cones, do not conform with this generalization. The selectivity with which the synaptic terminals of the different cones are connected together by their invaginating basal processes was also examined. These processes link neighbouring synaptic terminals of differently coloured cones: specifically, principal (red) cone basal processes invaginate accessory (green) cone pedicles, and vice versa. Single (blue) cone basal processes connect only to accessory cone pedicles, but that synaptic relation is not reciprocated. These synapses between the cones have important bearing upon interpretation of the bipolar cell connectivity patterns. In their light, the interaction between colour channels which the convergence of different cones onto the mixed cone bipolar dendrites mediates, seems to re-iterate a process already undertaken more peripherally. Likewise, whereas the anatomy of the selective cone bipolars appears designed to convey activity from the individual cone populations, the responses of the receptors they sample must already be influenced by activity in other colour channels.

Static and Dynamic Membrane Properties of Large-Terminal Bipolar Cells From Goldfish Retina: Experimental Test of a Compartment Model

1997 ◽  
Vol 78 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Steven Mennerick ◽  
David Zenisek ◽  
Gary Matthews
Keyword(s):  
Equivalent Circuit ◽  
Experimental Test ◽  
Compartment Model ◽  
Bipolar Cells ◽  
Membrane Properties ◽  
Synaptic Terminal ◽  
Isolated Cells ◽  
Dynamic Membrane ◽  
Capacitance Measurements ◽  
Goldfish Retina

Mennerick, Steven, David Zenisek, and Gary Matthews. Static and dynamic membrane properties of large-terminal bipolar cells from goldfish retina: experimental test of a compartment model. J. Neurophysiol. 78: 51–62, 1997. Capacitance measurements allow direct studies of exocytosis and endocytosis in single synaptic terminals isolated from bipolar neurons of goldfish retina. Extending the technique to intact bipolar cells, with their more complex morphology, requires information about the cells' electrotonic architecture. To this end, we developed a compartment model of bipolar neurons isolated from goldfish retina and tested the model experimentally. The isolated cells retained morphology similar to that of bipolar neurons in intact goldfish retina. In whole cell recordings, current relaxations in response to 10-mV hyperpolarizing voltage pulses decayed with a biexponential time course. This suggests that the cells may be described by a two-compartment equivalent circuit with compartments corresponding to the soma/dendrites (6–10 pF) and synaptic terminal (2–4 pF), linked by the axial resistance (30–60 MΩ) of the axon. Four lines of evidence validate the equivalent circuit. 1) Similar estimates of somatic/dendritic and terminal capacitance were obtained whether the patch pipette was attached to the soma or to the synaptic terminal. 2) Estimates of the capacitance of the two compartments in intact cells were similar to estimates from somata and terminals that were isolated by cleavage of the connecting axon. 3) When current transients were generated from a more complete computer simulation of a bipolar neuron, analysis of the simulated transients with the use of the simple two-compartment model yielded capacitance estimates similar to those used to set up the simulation. 4) In isolated cells, the model gave estimates of depolarization-evoked increases in capacitance of the synaptic terminal that were quantitatively similar to those measured in terminals that were detached from the rest of the cell. Although in previous studies researchers have attempted to apply a similar equivalent circuit to more geometrically complex cells, morphological correlates of the equivalent-circuit compartments have been elusive. Our results demonstrate that in dissociated bipolar cells, precise morphological correlates can be assigned to the equivalent-circuit compartments. Additionally, the work shows that time-resolved capacitance measurements of synaptic transmitter release are possible in intact, isolated bipolar neurons and may also be feasible in intact tissue.

HCN channels are expressed differentially in retinal bipolar cells and concentrated at synaptic terminals

2003 ◽  
Vol 17 (10) ◽  
pp. 2084-2096 ◽  
Author(s):  
Frank Müller ◽  
Alexander Scholten ◽  
Elena Ivanova ◽  
Silke Haverkamp ◽  
Elisabeth Kremmer ◽  
...  
Keyword(s):  
Bipolar Cells ◽  
Hcn Channels ◽  
Synaptic Terminals ◽  
Retinal Bipolar Cells

Substance P modulates calcium current in retinal bipolar neurons

1992 ◽  
Vol 8 (6) ◽  
pp. 539-544 ◽  
Author(s):  
George S. Ayoub ◽  
Gary Matthews
Keyword(s):  
Substance P ◽  
Calcium Current ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Voltage Range ◽  
Patch Pipette ◽  
Voltage Dependent ◽  
Dependent Inhibition ◽  
Goldfish Retina

AbstractRetinal bipolar cells are non-spiking interneurons that relay information from photoreceptors to amacrine and ganglion cells. In turn, bipolar cells receive extensive synaptic feedback from amacrine cells, some of which contain neuropeptides, including substance P. We have examined the effect of substance P on single bipolar neurons isolated from goldfish retina and find that substance P (0.1–1 nM) produced a voltage-dependent inhibition of calcium current in these cells. The inhibition was strongest at negative potentials, with the peak suppression occurring at –20 to –30 mV; at potentials positive to 0 mV, there was little effect on calcium current. Thus, the net effect was to shift the voltage range of activation of calcium current toward more positive potentials. The inhibition of calcium current by substance P required GTP in the patch pipette and was blocked by internal GDP-β-S. Similar effects on calcium current were observed with somatostatin and metenkephalin, which are also found in amacrine cells.

Differential distribution of synaptotagmin immunoreactivity among synapses in the goldfish, salamander, and mouse retina

2003 ◽  
Vol 20 (1) ◽  
pp. 37-49 ◽  
Author(s):  
RUTH HEIDELBERGER ◽  
MENG M. WANG ◽  
DAVID M. SHERRY
Keyword(s):  
Posttranslational Modifications ◽  
Bipolar Cell ◽  
Plexiform Layer ◽  
Bipolar Cells ◽  
Mouse Retina ◽  
Inner Plexiform Layer ◽  
Calcium Sensor ◽  
Differential Distribution ◽  
Western Blots ◽  
Goldfish Retina

Synaptotagmin I is the leading candidate for the calcium sensor that triggers exocytosis at conventional synapses. However, physiological characterization of the calcium sensor for phasic release at the ribbon-style synapses of the goldfish Mb1 bipolar cell demonstrates a lower than predicted affinity for calcium, suggesting that a modified or different sensor triggers exocytosis at this synapse. We examined synaptotagmin immunolabeling in goldfish retina using two different antibodies directed against synaptotagmin epitopes that specifically labeled the expected 65-kDa protein on western blots of goldfish and mouse retinal membranes. The first antiserum strongly labeled conventional synapses in the inner plexiform layer (IPL), but did not label the ribbon-style synapse-containing synaptic terminals of goldfish Mb1 bipolar cells or photoreceptors. The second antibody also specifically labeled the expected 65-kDa protein on western blots but did not label any synapses in the goldfish retina. A third synaptotagmin antibody that performed poorly on western blots selectively labeled goldfish photoreceptor terminals. These results suggest that synaptotagmin may exist in at least three distinct “forms” in goldfish retinal synapses. These forms, which are differentially localized to conventional synapses, bipolar cell, and photoreceptor terminals, may represent differences in isoform, posttranslational modifications, epitope availability, and protein-binding partners. Labeling with these antibodies in the salamander and mouse retina revealed species-specific differences, indicating that synaptotagmin epitopes can vary across species as well as among synapses.

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