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.

Unusual coupling patterns of a cone bipolar cell in the rabbit retina

1999 ◽  
Vol 16 (6) ◽  
pp. 1029-1035 ◽  
Author(s):  
STEPHEN L. MILLS
Keyword(s):  
Gap Junctions ◽  
Bipolar Cell ◽  
Plexiform Layer ◽  
Cell Types ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Rabbit Retina ◽  
Retinal Bipolar Cells ◽  
Different Cell Types ◽  
Cone Bipolar Cells

In mammals, gap junctions between retinal bipolar cells are generally small and tracer coupling has not been previously demonstrated. In this study, Neurobiotin was injected into the Ba3-type cone bipolar cell, a medium-field cone bipolar cell that ramifies in sublamina a of the rabbit retina. Tracer spread to many other Ba3 bipolar cells, presumably through gap junctions. It also spread to a smaller field bipolar cell called the Ba1 that ramifies at the same depth of the inner plexiform layer. Injection of Neurobiotin into Ba1 bipolar cells did not produce staining beyond the injected cell. Tracer coupling from the Ba3 was therefore both heterologous, in that different cell types were stained, and asymmetric. The unusual properties of this bipolar cell suggest that its function may differ from that of most cone bipolar cells, which are narrow-field, do not overlap, and are poorly coupled to one another.

scholarly journals Heterocellular coupling between amacrine cell and ganglion cells

2018 ◽  
Author(s):  
Robert E. Marc ◽  
Crystal Sigulinsky ◽  
Rebecca L. Pfeiffer ◽  
Daniel Emrich ◽  
James R. Anderson ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Ganglion Cell ◽  
Bipolar Cell ◽  
Amacrine Cell ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Amacrine Cells ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Tem Analysis

AbstractAll superclasses of retinal neurons display some form of electrical coupling including the key neurons of the inner plexiform layer: bipolar cells (BCs), amacrine or axonal cells (ACs) and ganglion cells (GCs). However, coupling varies extensively by class. For example, mammalian rod bipolar cells form no gap junctions at all, while all cone bipolar cells form class-specific coupling arrays, many of them homocellular in-superclass arrays. Ganglion cells are unique in that classes with coupling predominantly form heterocellular cross-class arrays of ganglion cell::amacrine cell (GC::AC) coupling in the mammalian retina. Ganglion cells are the least frequent superclass in the inner plexiform layer and GC::AC gap junctions are sparsely arrayed amidst massive cohorts of AC::AC, bipolar cell BC::BC, and AC::BC gap junctions. Many of these gap junctions and most ganglion cell gap junctions are suboptical, complicating analysis of specific ganglion cells. High resolution 2 nm TEM analysis of rabbit retinal connectome RC1 allows quantitative GC::AC coupling maps of identified ganglion cells. Ganglion cells classes apparently avoid direct cross-class homocellular coupling altogether even though they have opportunities via direct membrane touches, while transient OFF alpha ganglion cells and transient ON directionally selective (DS) ganglion cells are strongly coupled to distinct amacrine / axonal cell cohorts.A key feature of coupled ganglion cells is intercellular metabolite flux. Most GC::AC coupling involves GABAergic cells (γ+ amacrine cells), which results in significant GABA flux into ganglion cells. Surveying GABA coupling signatures in the ganglion cell layer across species suggests that the majority of vertebrate retinas engage in GC::AC coupling.Multi-hop synaptic queries of the entire RC1 connectome clearly profiles the coupled amacrine and axonal cells. Photic drive polarities and source bipolar cell class selec-tivities are tightly matched across coupled cells. OFF alpha ganglion cells are coupled to OFF γ+ amacrine cells and transient ON DS ganglion cells are coupled to ON γ+ amacrine cells including a large interstitial axonal cell (IAC). Synaptic tabulations show close matches between the classes of bipolar cells sampled by the coupled amacrine and ganglion cells. Further, both ON and OFF coupling ganglion networks show a common theme: synaptic asymmetry whereby the coupled γ+ neurons are also presynaptic to ganglion cell dendrites from different classes of ganglion cells outside the coupled set. In effect, these heterocellular coupling patterns enable an excited ganglion cell to directly inhibit nearby ganglion cells of different classes. Similarly, coupled γ+ amacrine cells engaged in feedback networks can leverage the additional gain of bipolar cell synapses in shaping the signaling of a spectrum of downstream targets based on their own selective coupling with ganglion cells.

Rod bipolar cells in the cone-dominated retina of the tree shrew Tupaia belangeri

1991 ◽  
Vol 6 (6) ◽  
pp. 629-639 ◽  
Author(s):  
Brigitte Müller ◽  
Leo Peichl
Keyword(s):  
Bipolar Cell ◽  
Tree Shrew ◽  
Light And Electron Microscopy ◽  
Plexiform Layer ◽  
Bipolar Cells ◽  
Peripheral Retina ◽  
Inner Plexiform Layer ◽  
Cat Retina ◽  
Topographical Distribution ◽  
Rod Bipolar Cells

AbstractThe tree shrew has a cone-dominated retina with a rod proportion of 5%, in contrast to the common mammalian pattern of rod-dominated retinae. As a first step to elucidate the rod pathway in the tree shrew retina, we have demonstrated the presence of rod bipolar cells and studied their morphology and distribution by light and electron microscopy.Rod bipolar cells were labeled with an antiserum against the protein kinase C (PKC), a phosphorylating enzyme. Intense PKC immunoreactivity was found in perikarya, axons, and dendrites of rod bipolar cells. The cell bodies are located in the sclerad part of the inner nuclear layer, the dendrites ascend to the outer plexiform layer where they are postsynaptic to rod spherules, and an axon descends towards the inner plexiform layer (IPL). The axons branch, and terminate in the vitread third of the IPL where mammalian rod bipolar cells are known to terminate. Two amacrine cell processes are always seen as the postsynaptic elements (dyads). Dendritic and axonal arbors of rod bipolar cells are rather large, up to 100 μm in diameter. The topographical distribution of the rod bipolar cells was analyzed quantitatively in tangential sections.Their density ranges from 300 cells/mm2 in peripheral retina to 900 cells/mm2 more centrally. The distribution is rather flat with no local extremes. Consistent with the low rod proportion in tree shrew, the rod bipolar cell density is low compared to the rod-dominated cat retina for example (36,000-47,000 rod bipolar cells/mm2). Rod-to-rod bipolar cell ratios in the tree shrew retina range from smaller than 1 to about 7, and thus are also lower than in cat.

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.

Convergence and divergence of cones onto bipolar cells in the central area of cat retina

1990 ◽  
Vol 330 (1258) ◽  
pp. 323-328 ◽  
Keyword(s):  
Bipolar Cell ◽  
Central Area ◽  
Plexiform Layer ◽  
Preceding Paper ◽  
Bipolar Cells ◽  
Visual Signal ◽  
Wide Field ◽  
Inner Plexiform Layer ◽  
Type B ◽  
Cat Retina

In the central area of cat retina the cone bipolar cells that innervate sublamina b of the inner plexiform layer comprise five types, four with narrow dendritic fields and one with a wide dendritic field. This was shown in the preceding paper (Cohen & Sterling 1990 a ) by reconstruction from electron micrographs of serial sections. Here we show by further analysis of the same material that the coverage factor (dendritic spread x cell density) is about one for each of the narrow-field types (b 1 , b 2 , and b 4 ). The same is probably true for the other narrow-field type (b 3 ), but this could not be proved because its dendrites were too fine to trace. The dendrites of types b 1 , b 2 , and b 4 collect from all the cone pedicles within their reach and do not bypass local pedicles in favour of more distant ones. The dendrites of type b 5 , the wide-field cell, bypass many pedicles. On average 5.1±1.0 pedicles converge on a b 1 bipolar cell; 6.0±1.2 converge on a b 2 cell and 5.7±1.5 converge on a b 4 cell. Divergence within a type is minimal: one pedicle contacts only 1.2 b 1 cells, 1.0 b 2 cells, and 1.0 b 4 cells. Divergence across types is broad : each pedicle apparently contacts all four types of the narrow-field bipolar cells that innervate sublamina b . Each pedicle probably also contacts an additional 4—5 types of narrow-field bipolar cell that innervate sublamina a . There are several possible advantages to encoding the cone signal into multiple, parallel, narrow-field pathways. These include: tuning of pathways to transmit different temporal frequencies, use of ion channels with widely separated equilibrium potentials (to increase gain), and formation of different regulatory circuits in the inner plexiform layer. The latter possibility would permit different operations (e.g linear or nonlinear) to be performed on the visual signal on its way towards different types of ganglion cell.

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.

scholarly journals In vivo Morphometry of Inner Plexiform Layer (IPL) Stratification in the Human Retina With Visible Light Optical Coherence Tomography

2021 ◽  
Vol 15 ◽  
Author(s):  
Tingwei Zhang ◽  
Aaron M. Kho ◽  
Vivek J. Srinivasan
Keyword(s):  
Optical Coherence Tomography ◽  
Visual System ◽  
Visible Light ◽  
Human Subjects ◽  
Plexiform Layer ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Optical Coherence ◽  
On And Off Pathways

From the bipolar cells to higher brain visual centers, signals in the vertebrate visual system are transmitted along parallel on and off pathways. These two pathways are spatially segregated along the depth axis of the retina. Yet, to our knowledge, there is no way to directly assess this anatomical stratification in vivo. Here, employing ultrahigh resolution visible light Optical Coherence Tomography (OCT) imaging in humans, we report a stereotyped reflectivity pattern of the inner plexiform layer (IPL) that parallels IPL stratification. We characterize the topography of this reflectivity pattern non-invasively in a cohort of normal, young adult human subjects. This proposed correlate of IPL stratification is accessible through non-invasive ocular imaging in living humans. Topographic variations should be carefully considered when designing studies in development or diseases of the visual system.

scholarly journals Spectral inference reveals principal cone-integration rules of the zebrafish inner retina

2021 ◽  
Author(s):  
Philipp Bartel ◽  
Takeshi Yoshimatsu ◽  
Filip K Janiak ◽  
Tom Baden
Keyword(s):  
Bipolar Cell ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Equal Sign ◽  
Inner Retina ◽  
Temporal Variance ◽  
Set Up ◽  
Uv Cone ◽  
Integration Rules

In the vertebrate retina, bipolar cells integrate the signals from different cone types at two main sites: directly, via dendritic inputs in the outer retina, and indirectly, via axonal inputs in the inner retina. Of these, the functional wiring of the indirect route, involving diverse amacrine cell circuits, remains largely uncharted. However, because cone-photoreceptor types differ in their spectral sensitivities, insights into the total functional cone-integration logic of bipolar cell might be gained by linking spectral responses across these two populations of neurons. To explore the feasibility of such a "spectral-circuit-mapping" approach, we here recorded in vivo responses of bipolar cell presynaptic terminals in larval zebrafish to widefield but spectrally resolved flashes of light. We then mapped the results onto the previously established spectral sensitivity functions of the four cones. We find that this approach could explain ~95% of the spectral and temporal variance of bipolar cell responses by way of a simple linear model that combined weighted inputs from the cones with four stereotyped temporal components. This in turn revealed several notable integration rules of the inner retina. Overall, bipolar cells were dominated by red-cone inputs, often alongside equal sign inputs from blue- and green-cones. In contrast, UV-cone inputs were uncorrelated with those of the remaining cones. This led to a new axis of spectral opponency which was mainly set-up by red-/green-/blue-cone "Off" circuits connecting to "natively-On" UV-cone circuits in the outermost fraction of the inner plexiform layer – much as how key colour opponent circuits are established in mammals. Beyond this, and despite substantial temporal diversity that was not present in the cones, bipolar cell spectral tunings were surprisingly simple. They either approximately resembled both opponent and non-opponent spectral motifs already present in the cones or exhibited a stereotyped non-opponent broadband response. In this way, bipolar cells not only preserved the efficient spectral representations in the cones, but also diversified them to set up a total of six dominant spectral motifs which included three axes of spectral opponency. More generally, our results contribute to an emerging understanding of how retinal circuits for colour vision in ancestral cone-tetrachromats such as zebrafish may be linked to those found in mammals.

scholarly journals Neurotransmission plays contrasting roles in the maturation of inhibitory synapses on axons and dendrites of retinal bipolar cells

2015 ◽  
Vol 112 (41) ◽  
pp. 12840-12845 ◽  
Author(s):  
Mrinalini Hoon ◽  
Raunak Sinha ◽  
Haruhisa Okawa ◽  
Sachihiro C. Suzuki ◽  
Arlene A. Hirano ◽  
...  
Keyword(s):  
Bipolar Cell ◽  
Glycine Receptor ◽  
Gaba Release ◽  
Bipolar Cells ◽  
Receptor Expression ◽  
Inhibitory Synapses ◽  
Synapse Maturation ◽  
Retinal Bipolar Cells ◽  
Cellular Compartments

Neuronal output is modulated by inhibition onto both dendrites and axons. It is unknown whether inhibitory synapses at these two cellular compartments of an individual neuron are regulated coordinately or separately during in vivo development. Because neurotransmission influences synapse maturation and circuit development, we determined how loss of inhibition affects the expression of diverse types of inhibitory receptors on the axon and dendrites of mouse retinal bipolar cells. We found that axonal GABA but not glycine receptor expression depends on neurotransmission. Importantly, axonal and dendritic GABAA receptors comprise distinct subunit compositions that are regulated differentially by GABA release: Axonal GABAA receptors are down-regulated but dendritic receptors are up-regulated in the absence of inhibition. The homeostatic increase in GABAA receptors on bipolar cell dendrites is pathway-specific: Cone but not rod bipolar cell dendrites maintain an up-regulation of receptors in the transmission deficient mutants. Furthermore, the bipolar cell GABAA receptor alterations are a consequence of impaired vesicular GABA release from amacrine but not horizontal interneurons. Thus, inhibitory neurotransmission regulates in vivo postsynaptic maturation of inhibitory synapses with contrasting modes of action specific to synapse type and location.

Roles of aspartate and glutamate in synaptic transmission in rabbit retina. II. Inner plexiform layer

1985 ◽  
Vol 53 (3) ◽  
pp. 714-725 ◽  
Author(s):  
S. A. Bloomfield ◽  
J. E. Dowling
Keyword(s):  
Membrane Potential ◽  
Bipolar Cell ◽  
Ganglion Cells ◽  
Plexiform Layer ◽  
Bipolar Cells ◽  
Inner Plexiform Layer ◽  
Retinal Neurons ◽  
Inner Retina ◽  
Axon Terminals ◽  
Cell Responses

Intracellular recordings were obtained from amacrine and ganglion cells in the superfused, isolated retina-eyecup of the rabbit. The putative neurotransmitters aspartate, glutamate, and several of their analogues were added to the superfusate while the membrane potential and light-responsiveness of the retinal neurons were monitored. Both L-aspartate and L-glutamate displayed excitatory actions on the activity of the vast majority of amacrine and ganglion cells studied. However, these agents occasionally appeared to inhibit the responses of the inner retinal neurons by producing hyperpolarization of the membrane potential and blockage of the light-evoked responses. In either case, the effects of aspartate and glutamate were indistinguishable. The glutamate analogues kainate and quisqualate produced strong excitatory effects on the responses of amacrine and ganglion cells at concentrations some 200-fold less than those needed to obtain similar effects with aspartate or glutamate. The aspartate analogue, n-methyl DL-aspartate (NMDLA), also produced strong excitatory effects but was approximately three times less potent than kainate or quisqualate. On one occasion, we encountered a ganglion cell that was depolarized by kainate, but hyperpolarized by NMDLA. The glutamate antagonist alpha-methyl glutamate and the aspartate antagonist alpha-amino adipate effectively blocked the responses of amacrine and ganglion cells. However, on any one cell, one antagonist was always clearly more potent than the other. We examined the actions of the glutamate analogue 2-amino-4-phosphonobutyrate (APB) on the responses of inner retinal neurons and found that it selectively abolished all "on" activity in the inner retina. Together with our finding that APB selectively abolishes on-bipolar cell responses (see Ref. 6), these data support the hypothesis that on-bipolar cells subserve the "on" activity of amacrine and ganglion cells. Our data suggest that aspartate and glutamate are excitatory transmitters in the inner retina, possibly being released from bipolar cell axon terminals in the inner plexiform layer.

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