Synaptic elements for GABAergic feed-forward signaling between HII horizontal cells and blue cone bipolar cells are enriched beneath primate S-cones.
Synaptic elements for GABAergic feed-forward signaling between HII horizontal cells and blue cone bipolar cells are enriched beneath primate S-cones.
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DOI：
10.1371/journal.pone.0088963
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Neitz J
中科院分区：
文献类型：
--
作者：
Puller C;Haverkamp S;Neitz M;Neitz J
哺乳动物视网膜水平细胞的功能和突触特征仍有争议。存在从水平细胞到视锥细胞的反馈信号和从水平细胞到双极细胞的前馈信号的证据，但后者的细节仍然难以捉摸。在这里，免疫组织化学和共聚焦显微镜被用来分析SNARE蛋白syntaxin-4，GABA受体亚基α1和ρ，阳离子-氯离子共转运蛋白NKCC和KCC 2在灵长类视网膜外丛状层的表达模式。在猕猴视网膜中，如以前在其他物种中观察到的，突触融合蛋白-4表达在视锥蒂和视杆小球的水平细胞的树突和轴突末梢上。在视锥细胞中，syntaxin-4密集地聚集在两条带中，分别位于水平细胞树突尖端和桥粒样连接处。有趣的是，在水平细胞可以直接突触到双极细胞上的较低带中，突触融合蛋白-4在短波长敏感（S）锥下方高度富集，并与钙结合蛋白（HII水平细胞的标志物）共定位。在小鼠或地松鼠中均未观察到S-视锥的富集。此外，大量的GABA受体和阳离子-氯协同转运亚基被发现灵长类动物的S-锥。最后，虽然syntaxin-4表达的HI和HII水平的细胞类型，强烈的聚类和共定位与钙结合蛋白在S-锥表明增强表达HII细胞。两者合计，GABA受体锥蒂下，氯转运蛋白，和syntaxin-4是一组突触的蛋白质，这将是必需的GABA介导的前馈途径，通过水平细胞携带信号直接从锥双极细胞的推定成分。
The functional roles and synaptic features of horizontal cells in the mammalian retina are still controversial. Evidence exists for feedback signaling from horizontal cells to cones and feed-forward signaling from horizontal cells to bipolar cells, but the details of the latter remain elusive. Here, immunohistochemistry and confocal microscopy were used to analyze the expression patterns of the SNARE protein syntaxin-4, the GABA receptor subunits α1 and ρ, and the cation-chloride cotransporters NKCC and KCC2 in the outer plexiform layer of primate retina. In macaque retina, as observed previously in other species, syntaxin-4 was expressed on dendrites and axon terminals of horizontal cells at cone pedicles and rod spherules. At cones, syntaxin-4 appeared densely clustered in two bands, at horizontal cell dendritic tips and at the level of desmosome-like junctions. Interestingly, in the lower band where horizontal cells may synapse directly onto bipolar cells, syntaxin-4 was highly enriched beneath short-wavelength sensitive (S) cones and colocalized with calbindin, a marker for HII horizontal cells. The enrichment at S-cones was not observed in either mouse or ground squirrel. Furthermore, high amounts of both GABA receptor and cation-chloride cotransporter subunits were found beneath primate S-cones. Finally, while syntaxin-4 was expressed by both HI and HII horizontal cell types, the intense clustering and colocalization with calbindin at S-cones indicated an enhanced expression in HII cells. Taken together, GABA receptors beneath cone pedicles, chloride transporters, and syntaxin-4 are putative constituents of a synaptic set of proteins which would be required for a GABA-mediated feed-forward pathway via horizontal cells carrying signals directly from cones to bipolar cells.
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DOI：
10.1523/jneurosci.1218-09.2009
发表时间：
2009-07-01
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Crook JD;Davenport CM;Peterson BB;Packer OS;Detwiler PB;Dacey DM
通讯作者：
Dacey DM
影响因子：
1.8
作者：
Dacey, D;Packer, OS;Lee, B
通讯作者：
Lee, B
影响因子：
5.5
作者：
BAYLOR, DA;FUORTES, MGF;OBRYAN, PM
通讯作者：
OBRYAN, PM
影响因子：
64.8
作者：
DACEY, DM;LEE, BB
通讯作者：
LEE, BB
DOI：
10.1007/bf00500621
发表时间：
1987-01-01
期刊：
HISTOCHEMISTRY
影响因子：
--
作者：
AGARDH, E;EHINGER, B;WU, JY
通讯作者：
WU, JY