Cone Photoreceptors in Bass Retina Use Two Connexins to Mediate Electrical Coupling

O’Brien, John; Nguyen, H. Bao; Mills, Steven

doi:10.1523/jneurosci.1248-04.2004

Cited by 59 publications

(105 citation statements)

References 64 publications

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“…We treated half of each membrane preparation with alkaline phosphatase (AP) to remove phosphate groups from the protein. A monoclonal antibody against Cx35 (figure 3, panel A) identified Cx35 as a diffuse band running around 30-32 kDa, in keeping with previous reports (O 'Brien et al, 1998;Pereda et al, 2003;O'Brien et al, 2004). The phospho-Ser110 antibody (panel B) labeled the same band in untreated retinal membranes.…”

Section: Conserved Regulatory Phosphorylation Sites Are Phosphorylatesupporting

confidence: 87%

“…Some Cx35 plaques showed extensive, bright phospho-Ser276 labeling while others had essentially none (arrow). One readily identifiable group of Cx35 gap junctions were the extremely large (up to 32 μm 2 ) plaques distributed in two bands, one each in sublamina a and sublamina b, that we have previously reported (O'Brien et al, 2004). The cell type harboring these gap junctions is unknown, although they fit the description of the large gap junctions between large-caliber amacrine cell processes identified by Marc et al 1988 in TEM studies of goldfish retina.…”

Section: Phosphorylation Of Cx35 Is Controlled At the Level Of Indivisupporting

confidence: 53%

“…For retinal membrane preparations, blots were incubated with affinity purified phospho-specific antibodies diluted to 1 μg/ml in high-salt TBST (500 mM NaCl, 3 mM KCl, 25 mM Tris-Cl, pH 7.4, 0.1% Tween-20) plus 2% nonfat dry milk. Blots were also probed with a monoclonal anti-Cx35/36 antibody (Chemicon, Temecula, CA) that was developed against the perch Cx35 intracellular loop (O'Brien et al, 2004) at 1 μg/ml in the same solution. Blots were developed with peroxidase-linked secondary antibodies (Pierce) and detected by chemiluminescence using x-ray film.…”

Section: Western Blotmentioning

confidence: 99%

“…In the outer plexiform layer, where Cx35 is present in both cone and bipolar cell gap junctions (O'Brien et al, 2004), the phospho-Ser276 antibody labeled several morphologically distinct populations of Cx35 gap junctions (figure 9). Large plaques that varied from round to ellipsoid (arrows), and which may represent bipolar cell gap junctions, showed strong phospho-Ser276 labeling in both dark-and light-adapted retina.…”

Section: Phosphorylation Of Cx35 Is Controlled At the Level Of Indivimentioning

confidence: 99%

“…It has been found in a large number of neurons in the retina and central nervous system. In the retina this connexin is associated with AII amacrine cell gap junctions Mills et al, 2001), cone photoreceptor gap junctions (Feigenspan et al, 2004;O'Brien et al, 2004), and rod photoreceptor gap junctions in some species (Zhang & Wu, 2004). It is also apparent that a large number of other neurons use this connexin (O'Brien et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

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Connexin 35/36 is phosphorylated at regulatory sites in the retina

Kothmann

Li²,

Burr

et al. 2007

Vis Neurosci

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Connexin 35/36 is the most widespread neuronal gap junction protein in the retina and central nervous system. Electrical and/or tracer coupling in a number of neuronal circuits that express this connexin are regulated by light adaptation. In many cases the regulation of coupling depends on signaling pathways that activate protein kinases such as PKA, and Cx35 has been shown to be regulated by PKA phosphorylation in cell culture systems. To examine whether phosphorylation might regulate Cx35/36 in the retina we developed phospho-specific polyclonal antibodies against the two regulatory phosphorylation sites of Cx35 and examined the phosphorylation state of this connexin in the retina. Western blot analysis with hybrid bass retinal membrane preparations showed Cx35 to be phosphorylated at both the Ser110 and Ser276 sites, and this labeling was eliminated by alkaline phosphatase digestion. The homologous sites of mouse and rabbit Cx36 were also phosphorylated in retinal membrane preparations. Quantitative confocal immunofluorescence analysis showed gap junctions identified with a monoclonal anti-Cx35 antibody to have variable levels of phosphorylation at both the Ser110 and Ser276 sites. Unusual gap junctions that could be identified by their large size (up to 32 μm 2 ) and location in the IPL showed a prominent shift in phosphorylation state from heavily phosphorylated in nighttime, dark-adapted retina to weakly phosphorylated in daytime, light-adapted retina. Both Ser110 and Ser276 sites showed significant changes in this manner. Under both lighting conditions other gap junctions varied from non-phosphorylated to heavily phosphorylated. We predict that changes in the phosphorylation states of these sites correlate with changes in the degree of coupling through Cx35/36 gap junctions. This leads to the conclusion that connexin phosphorylation mediates changes in coupling in some retinal networks. However, these changes are not global and likely occur in a cell type-specific or possibly a gap junction-specific manner.

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Section: Conserved Regulatory Phosphorylation Sites Are Phosphorylatesupporting

confidence: 87%

Section: Phosphorylation Of Cx35 Is Controlled At the Level Of Indivisupporting

confidence: 53%

Section: Western Blotmentioning

confidence: 99%

Section: Phosphorylation Of Cx35 Is Controlled At the Level Of Indivimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Connexin 35/36 is phosphorylated at regulatory sites in the retina

Kothmann

Li²,

Burr

et al. 2007

Vis Neurosci

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Components and properties of the G3 ganglion cell circuit in the rabbit retina

Hoshi

Mills

2008

J of Comparative Neurology

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Each point on the retina is sampled by about 15 types of ganglion cell, each of which is an element in a circuit also containing specific types of bipolar cell and amacrine cell. Only a few of these circuits are well characterized. We found that intracellular injection of Neurobiotin into a specific ganglion cell type targeted by fluorescent markers also stained an asymmetrically branching ganglion cell. It was also tracer-coupled to an unusual type of amacrine cell whose dendrites were strongly asymmetric, coursing in a narrow bundle from the soma in the dorsal direction only. The dendritic field of the ganglion cell stratifies initially in sublamina b (the ON layers), but with few specializations and branches, and then more extensively in sublamina a (the OFF layers) at the level of the processes of the coupled amacrine cell. Intersections of the ganglion and amacrine cell processes contain puncta immunopositive for Cx36. Additionally, we found that the dopaminergic amacrine cell makes contact with both the ganglion cell and the amacrine cell, and that a bipolar cell immunopositive for calbindin synapses onto the sublamina b processes of the ganglion cell. Dopamine D 1 receptor activation reduced tracer flow to the amacrine cells. We have thus targeted and characterized two poorly understood retinal cell types and placed them with two other cell types in a substantial portion of a new retinal circuit. This unique circuit comprised of pronounced asymmetries in the ganglion cell and amacrine cell dendritic fields may result in a substantial orientation bias. Indexing termsganglion cell; amacrine cell; bipolar cell; connexin36; gap junction; orientation selectivityThe visual processing stream as it emanates from the vertebrate retina consists of numerous parallel pathways carried by ≈15 types of ganglion cell (Dacey, 1999;Masland, 2001;Wässle, 2004). The dendritic fields of neighboring ganglion cells of a given type are positioned in a mosaic so as to sample the visual scene completely. Each individual ganglion cell is a portion of a retinal circuit whose characteristics are differentiated from those of other ganglion cell types in large part by their synaptic contacts-which of the dozen or so bipolar cell types relays the output of the photoreceptor to them and which of the 30 or more amacrine cells synapse upon these bipolar cells, the ganglion cell itself, or other amacrine cells. Identification of these repeating cell assemblies is a major step in unraveling the function of the retina and early vision.It has recently become clear that many, perhaps most, retinal ganglion cells are coupled via gap junctions to specific types of amacrine cell which play a part in determining the function of the circuit and also serve as a diagnostic tool for establishing cell type. The role of these coupled amacrine cells is not presently known. They may contribute to synchronized firing of NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript the ganglion cells (Mastronarde, 1983;Brivanlou et al., ...

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Histamine receptors of cones and horizontal cells in Old World monkey retinas

Vila

Satoh

Rangel

et al. 2011

J of Comparative Neurology

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In primates the retina receives input from histaminergic neurons in the posterior hypothalamus that are active during the day. In order to understand how this input contributes to information processing in Old World monkey retinas, we have been localizing histamine receptors (HR) and studying the effects of histamine on the neurons that express them. Previously, we localized HR3 to the tips of ON bipolar cell dendrites and showed that histamine hyperpolarizes the cells via this receptor. We raised antisera against synthetic peptides corresponding to an extracellular domain of HR1 between the 4th and 5th transmembrane domains and to an intracellular domain near the carboxyl terminus of HR2. Using these, we localized HR1 to horizontal cells and a small number of amacrine cells and localized HR2 to puncta closely associated with synaptic ribbons inside cone pedicles. Consistent with this, HR1 mRNA was detected in horizontal cell perikarya and primary dendrites and HR2 mRNA was found in cone inner segments. We studied the effect of 5 µM exogenous histamine on primate cones in macaque retinal slices. Histamine reduced Ih at moderately hyperpolarized potentials, but not the maximal current. This would be expected to increase the operating range of cones and conserve ATP in bright, ambient light. Thus, all three major targets of histamine are in the outer plexiform layer, but the retinopetal axons containing histamine terminate in the inner plexiform layer. Taken together, the findings in these three studies suggest that histamine acts primarily via volume transmission in primate retina.

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Cone Photoreceptors in Bass Retina Use Two Connexins to Mediate Electrical Coupling

Cited by 59 publications

References 64 publications

Connexin 35/36 is phosphorylated at regulatory sites in the retina

Connexin 35/36 is phosphorylated at regulatory sites in the retina

Components and properties of the G3 ganglion cell circuit in the rabbit retina

Histamine receptors of cones and horizontal cells in Old World monkey retinas

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