Synaptic Organization of an organotypic slice culture of the mammalian retina

1996 ◽  
Vol 13 (4) ◽  
pp. 759-771 ◽  
Author(s):  
Marco Sassoè-Pognetto ◽  
Andreas Feigenspan ◽  
Joachim Bormann ◽  
Heinz Wässle
Keyword(s):  
Hot Spots ◽  
Plexiform Layer ◽  
Slice Culture ◽  
Inner Plexiform Layer ◽  
Synaptic Organization ◽  
Glycine Receptors ◽  
Ribbon Synapses ◽  
Organotypic Slice Culture ◽  
Transmitter Receptors

AbstractVertical Slices of postnatal day 6 (P6) rat retina were cut and cultured using the roller-tube technique. The organotypic differentiation during a culture period of up to 30 days has been described in a previous study (Feigenspan et al., 1993a). Here we concentrated on the synaptic organization in the retinal slice culture. Electron microscopy revealed the presence of ribbon synapses in the outer plexiform layer and conventional and ribbon syanpses in the inner plexiform layer. Immunofluroscence with antibodies that recognize specific subunits of GABAA or glycine receptors revealed a punctuate distribution of the receptors. They were aggregated in “hot spots” that correspond to a concentration of receptors at postsynaptic sites. Different isoforms of GABAA and glycine receptors occured in the slice cultures. The experiments show that there is a differentiation of synapses and a diversity of transmitter receptors in the slice cultures that is comparable to the in vivo retina.

Synaptic organization of the inner plexiform layer of the retina of Xenopus laevis

1978 ◽  
Vol 201 (1142) ◽  
pp. 57-72 ◽  
Keyword(s):  
Xenopus Laevis ◽  
South African ◽  
Plexiform Layer ◽  
Uranyl Acetate ◽  
Inner Plexiform Layer ◽  
Lead Citrate ◽  
Synaptic Organization ◽  
Ribbon Synapses ◽  
Layer I ◽  
Clawed Frog

The inner plexiform layer (i. p. l.) of the retina of the South African clawed frog, Xenopus laevis , was studied by electron microscopy. Photomicrographs of single sections revealed synaptic morphologies comparable to those in other vertebrate retinae. In a partial serial reconstruction of a bipolar terminal, however, some unusual arrangements were found. The bipolar terminal made some synapses that at first examination appeared much like conventional synapses, but subsequent sections always revealed an extremely small ribbon. Many of the ribbon synapses were found to contact more than two postsynaptic processes; up to six pro­cesses postsynaptic to one ribbon contact were seen. A reciprocal synapse was not evident at each ribbon synapse. Montages of the entire width of the inner plexiform layer were constructed from sections cut from four different locations across the retina. The numbers of conventional and ribbon synapses per unit volume of tissue were determined. The synaptic densities found in Xenopus were much lower than those reported for other frogs. Differences in synaptic densities from the four locations were found to be statistically insignificant. The overall amacrine/bipolar synapse ratio was 6.8/1. The synaptic den­sities in the inner plexiform layer did not change when the tissue was stained with lead citrate alone rather than with uranyl acetate and lead citrate. The functional significance of the morphological and quantitative synaptic arrangements in Xenopus i. p. l. is discussed, and the synaptic organization is compared to that of other amphibia and vertebrates.

Glycine receptor immunoreactivity is localized at amacrine synapses in cat retina

1991 ◽  
Vol 7 (6) ◽  
pp. 611-618 ◽  
Author(s):  
Roberta G. Pourcho ◽  
Michael T. Owczarzak
Keyword(s):  
Ganglion Cells ◽  
Glycine Receptor ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Electron Microscopic Level ◽  
Inner Plexiform Layer ◽  
Glycine Receptors ◽  
Electron Microscopic ◽  
Cat Retina

AbstractImmunocytochemical techniques were used to localize strychnine-sensitive glycine receptors in cat retina. Light microscopy showed staining in processes ramifying throughout the inner plexiform layer and in cell bodies of both amacrine and ganglion cells. At the electron-microscopic level, receptor immunoreactivity was seen to be clustered at sites postsynaptic to amacrine cells. In contrast, bipolar cells were neither presynaptic nor postsynaptic elements at sites of glycine receptor staining. Double-label studies verified the presence of glycine immunoreactivity in amacrine terminals presynaptic to glycine receptors. These findings support a role for glycine as an inhibitory neurotransmitter in amacrine cells.

Synaptic connections involving immunoreactive glycine receptors in the turtle retina

1993 ◽  
Vol 10 (5) ◽  
pp. 907-914 ◽  
Author(s):  
Charles L. Zucker ◽  
Berndt Ehinger
Keyword(s):  
Amacrine Cell ◽  
Ganglion Cells ◽  
Glycine Receptor ◽  
Plexiform Layer ◽  
Photoreceptor Cells ◽  
Bimodal Distribution ◽  
Inner Nuclear Layer ◽  
Inner Plexiform Layer ◽  
Glycine Receptors ◽  
Cell Processes

AbstractThe distribution of glycine receptors in the turtle retina was studied with the aid of a monoclonal antibody that detects the 93-kD protein associated with the strychnine-sensitive glycine receptor. Light microscopically, receptors were found in the inner plexiform layer and, more sparsely, in the innermost parts of the inner nuclear layer. No receptors were seen to be associated with photoreceptor cells, horizontal cells, or any other structures in the distal inner nuclear layer or outer plexiform layer. Ultrastructurally, glycine receptors were found on the inner face of postsynaptic membranes of processes from amacrine and presumed ganglion cells and always involved amacrine cell processes as the presynaptic element. Such glycine receptor immunoreactive synapses onto amacrine cell processes were distributed throughout the inner plexiform layer with a peak density near the middle. On the other hand, output synapses onto ganglion cell processes displaying immunoreactive glycine receptor sites showed a bimodal distribution in the inner plexiform layer. Glycine receptor immunoreactivity was not detected on bipolar cells, but presumed glycine-utilizing processes (i.e. those presynaptic to immunoreactive glycine receptors) were occasionally found to be postsynaptic in bipolar cell dyads. The majority of the synaptic input to the presumed glycine-utilizing amacrine cell processes was from other amacrine processes, some of which were themselves glycine utilizing. The observations suggest that glycinergic synapses in the turtle retina are, to a large extent, engaged in processing interamacrine signals.

In vivo development of retinal ON-bipolar cell axonal terminals visualized in nyx::MYFP transgenic zebrafish

2006 ◽  
Vol 23 (5) ◽  
pp. 833-843 ◽  
Author(s):  
ERIC H. SCHROETER ◽  
RACHEL O.L. WONG ◽  
RONALD G. GREGG
Keyword(s):  
Bipolar Cell ◽  
Plexiform Layer ◽  
Transgenic Fish ◽  
Bipolar Cells ◽  
Regulatory Sequences ◽  
Inner Plexiform Layer ◽  
Fixed Tissue ◽  
Different Ages ◽  
Retinal Bipolar Cells

Axonal differentiation of retinal bipolar cells has largely been studied by comparing the morphology of these interneurons in fixed tissue at different ages. To better understand how bipolar axonal terminals develop in vivo, we imaged fluorescently labeled cells in the zebrafish retina using time-lapse confocal and two photon microscopy. Using the upstream regulatory sequences from the nyx gene that encodes nyctalopin, we constructed a transgenic fish in which a subset of retinal bipolar cells express membrane targeted yellow fluorescent protein (MYFP). Axonal terminals of these YFP-labeled bipolar cells laminated primarily in the inner half of the inner plexiform layer, suggesting that they are likely to be ON-bipolar cells. Transient expression of MYFP in isolated bipolar cells indicates that two or more subsets of bipolar cells, with one or two terminal boutons, are labeled. Live imaging of YFP-expressing bipolar cells in the nyx::MYFP transgenic fish at different ages showed that initially, filopodial-like structures extend and retract from their primary axonal process throughout the inner plexiform layer (IPL). Over time, filopodial exploration becomes concentrated at discrete foci prior to the establishment of large terminal boutons, characteristic of the mature form. This sequence of axonal differentiation suggests that synaptic targeting by bipolar cell axons may involve an early process of trial and error, rather than a process of directed outgrowth and contact. Our observations represent the first in vivo visualization of axonal development of bipolar cells in a vertebrate retina.

Morphological differentiation of bipolar cells in the ferret retina

1999 ◽  
Vol 16 (6) ◽  
pp. 1133-1144 ◽  
Author(s):  
E.D. MILLER ◽  
M.N. TRAN ◽  
G.-K. WONG ◽  
D.M. OAKLEY ◽  
R.O.L. WONG
Keyword(s):  
Visual Processing ◽  
Plexiform Layer ◽  
Morphological Differentiation ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Axon Terminals ◽  
Ribbon Synapses ◽  
Rod Bipolar Cells ◽  
Cone Bipolar Cells ◽  
Dye Labeling

Bipolar cells are not only important for visual processing but input from these cells may underlie the reorganization of ganglion cell dendrites in the inner plexiform layer (IPL) during development. Because little is known about the development of bipolar cells, here we have used immunocytochemical markers and dye labeling to identify and follow their differentiation in the neonatal ferret retina. Putative cone bipolar cells were immunoreacted for calbindin and recoverin, and rod bipolar cells were immunostained for protein kinase C (PKC). Our results show that calbindin-immunoreactive cone bipolar cells appear at postnatal day 15 (P15), at which time their axonal terminals are already localized to the inner half of the IPL. By contrast, recoverin-immunoreactive cells with terminals in the IPL are present at birth, but many of these cells may be immature photoreceptors. By the second postnatal week, recoverin-positive cells resembling cone bipolar cells were clearly present, and with increasing age, two distinct strata of immunolabeled processes occupied the IPL. PKC-containing rod bipolar cells emerged by the fourth postnatal week and at this age have stratified arbors in the inner IPL. The early bias of bipolar axonal arbors in terminating in the inner or outer half of the IPL is confirmed by dye labeling of cells with somata in the inner nuclear layer. At P10, several days before ribbon synapses have been previously observed in the ferret IPL, the axon terminals of all dye-labeled bipolar cells were clearly stratified. The results suggest that bipolar cells could provide spatially localized interactions that are suitable for guiding dendritic lamination in the inner retina.

Sign in / Sign up

Export Citation Format

Share Document