ON cone bipolar cell axonal synapses in the OFF inner plexiform layer of the rabbit retina

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.

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

Visual Neuroscience ◽

10.1017/s0952523806230219 ◽

2006 ◽

Vol 23 (5) ◽

pp. 833-843 ◽

Cited By ~ 35

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.

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Heterocellular coupling between amacrine cell and ganglion cells

10.1101/328815 ◽

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.

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Ultrastructural Circuitry in Retinal Cell Transplants to Rat Retina

Journal of Neural Transplantation and Plasticity ◽

10.1155/np.1994.17 ◽

1994 ◽

Vol 5 (1) ◽

pp. 17-29 ◽

Cited By ~ 13

Author(s):

Charles L. Zucker ◽

Berndt Ehinger ◽

Magdalene Seiler ◽

Robert B. Aramant ◽

Alan R. Adolph

Keyword(s):

Bipolar Cell ◽

Visual Information ◽

Pigment Epithelium ◽

Plexiform Layer ◽

Photoreceptor Cells ◽

Cell Types ◽

Retinal Cell ◽

Inner Plexiform Layer ◽

Cell Transplants ◽

Normal Differentiation

The development of five transplants of fetal retinal tissue to adult rat eyes was examined with the electron microscope. The transplants were of 9 to 10 weeks total age after conception in four cases and 20 weeks in one case. They were at stage E15 when transplanted. Transplants developed in both the epiretinal and subretinal spaces.The transplants were heterogeneously developed with some parts showing almost normal differentiation and others little. Subretinal transplants examined in this study were more developed than epiretinal grafts. Photoreceptor cells developed both inner and outer segments. Their synaptic terminals possessed output ribbon synapses with postsynaptic processes similar to those seen in normal retinas. In regions corresponding to the inner plexiform layer, the adult complement of synapses was seen, including advanced features such as serial synapses as well as reciprocal synapses at bipolar cell dyads. Incompletely differentiated synapses of both the amacrine and bipolar cell types were often observed, especially in the rat epiretinal transplants. Ganglion cell processes could not be identified with certainty.Although transplant cells were adjacent to host photoreceptor cells and pigment epithelium, obvious specializations or interactions were not observed. The experiments suggest that embryonic rat retinal cell transplants develop most or perhaps all of the structural components and neuronal circuitry necessary to transduce light and process some visual information.

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Amacrine-to-Amacrine Cell Inhibition in the Rabbit Retina

Journal of Neurophysiology ◽

10.1152/jn.90417.2008 ◽

2008 ◽

Vol 100 (4) ◽

pp. 2077-2088 ◽

Cited By ~ 44

Author(s):

Hain-Ann Hsueh ◽

Alyosha Molnar ◽

Frank S. Werblin

Keyword(s):

Patch Clamp ◽

Amacrine Cell ◽

Plexiform Layer ◽

Amacrine Cells ◽

Inner Plexiform Layer ◽

Gabaergic Inhibition ◽

Rabbit Retina ◽

No Inhibition ◽

Cell Inhibition ◽

In Cells

We studied the interactions between excitation and inhibition in morphologically identified amacrine cells in the light-adapted rabbit retinal slice under patch clamp. The majority of on amacrine cells received glycinergic off inhibition. About half of the off amacrine cells received glycinergic on inhibition. Neither class received any GABAergic inhibition. A minority of on, off, and on–off amacrine cells received both glycinergic on and GABAergic off inhibition. These interactions were found in cells with diverse morphologies having both wide and narrow processes that stratify in single or multiple layers of the inner plexiform layer (IPL). Most on–off amacrine cells received no inhibition and have monostratified processes confined to the middle of the IPL. The most common interaction between amacrine cells that we measured was “crossover inhibition,” where off inhibits on and on inhibits off. Although the morphology of amacrine cells is diverse, the interactions between excitation and inhibition appear to be relatively limited and specific.

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The shape and arrangement of the cholinergic neurons in the rabbit retina

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1984.0085 ◽

1984 ◽

Vol 223 (1230) ◽

pp. 101-119 ◽

Cited By ~ 228

Keyword(s):

Lucifer Yellow ◽

Cholinergic Neurons ◽

Dendritic Tree ◽

Plexiform Layer ◽

Inner Plexiform Layer ◽

Rabbit Retina ◽

Retinal Neuron ◽

Complete Filling ◽

Order Of Magnitude ◽

Dendritic Fields

The acetylcholine-synthesizing neurons of the rabbit retina were selectively stained by intraocular injection of the fluorescent dye 4, 6-diamidino-2-phenylindole (DAP1). Retinas were then isolated from the eye, fixed for 10-30 min with 4% paraformaldehyde, and mounted flat on the stage of a fluorescence microscope. The acetylcholine-synthesizing cells were penetrated under visual control by microelectrodes filled with lucifer yellow CH. When the dye was electrophoretically injected into the cells, complete filling of their dendrites often occurred. Cells were successfully injected as long as one month after fixation of the tissue. Complete or nearly complete filling of 281 cells was accomplished, at retinal locations systematically covering the retinal surface. The cells stained with DAPI were found to form a single morphological population. They have two to seven primary dendrites, which branch repeatedly within a narrow plane and form a round or slightly oval dendritic tree. The branching becomes very fine for the distal one third of the dendritic tree, and the dendrites there are studded with small swellings. The distal dendritic tree lies mainly within one of the two thin strata of the inner plexiform layer where acetylcholine is present. The shape and size of the dendritic tree are continuously graded across the retina ; the dendritic tree is narrower and the branching denser in the central retina, wider and sparser in the periphery. From knowledge of the population density and the shape of the neurons, one can reconstruct the array of dendrites that exists within the inner plexiform layer. The overlap of the dendritic fields is an order of magnitude greater than of any other retinal neuron previously described. Because the cells not only overlap widely but branch quite profusely, a very dense plexus of cholinergic dendrites is created.

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

Visual Neuroscience ◽

10.1017/s0952523800002625 ◽

1991 ◽

Vol 6 (6) ◽

pp. 629-639 ◽

Cited By ~ 21

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.

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