Evidence of metabotropic glutamate receptor subtypes found on catfish horizontal and bipolar retinal neurons.
Evidence of metabotropic glutamate receptor subtypes found on catfish horizontal and bipolar retinal neurons.
复制标题
在鲶鱼水平和双极视网膜神经元上发现代谢型谷氨酸受体亚型的证据。
DOI：
10.1016/s0306-4522(98)00512-0
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发表时间：
1999
期刊：
影响因子：
3.3
通讯作者：
Linn,CL
中科院分区：
文献类型：
--
作者：
Gafka,AC;Vogel,KS;Linn,CL
我们已经使用电生理学，药理学和免疫学技术，以确定哪些类的代谢型谷氨酸受体存在于视锥水平细胞在鲶鱼视网膜。急性分离的视锥水平细胞中的膜片钳记录提供了证据，表明存在I组和III组代谢型谷氨酸受体，并且与电压门控钙电流的调制有关。II组代谢型谷氨酸受体激动剂不影响钙电流。应用免疫细胞化学技术研究了鲶鱼视网膜中代谢型谷氨酸受体亚型的定位。用抗I组（代谢型谷氨酸受体1α、代谢型谷氨酸受体5）、II组（代谢型谷氨酸受体2/3）和III组（代谢型谷氨酸受体6）代谢型谷氨酸受体亚型的抗体标记急性分离的水平、双极和Müller细胞。免疫染色结果表明，视锥水平细胞表达I组（代谢型谷氨酸受体1α，代谢型谷氨酸受体5）和III组（代谢型谷氨酸受体6），但不表达II组（代谢型谷氨酸受体2/3）受体亚型，这与我们的电生理结果一致。暴露于抗代谢型谷氨酸受体1α、5或6抗体的视锥水平细胞均显示弥漫性整体染色，在树突状突起和细胞体上均发现深色免疫染色斑块。在鲶鱼双极细胞，所有四个抗代谢型谷氨酸受体抗体染色的过程和细胞体的双极细胞均匀。没有证据表明一组双极细胞不与抗代谢型谷氨酸受体抗体染色，尽管当双极细胞与抗代谢型谷氨酸受体6抗体孵育时发生了强免疫染色。Müller细胞未显示针对任何抗代谢型谷氨酸受体抗体的免疫染色。我们的非免疫对照证实免疫染色对抗原具有特异性，并进行免疫印迹以证明鲶鱼视网膜中抗体的特异性。这些结果支持了这一假设，即组I和III代谢型谷氨酸受体亚型被发现在鲶鱼水平细胞，和组I，II和III代谢型谷氨酸受体亚型表达在鲶鱼双极细胞。鲶鱼视锥水平细胞上的代谢型谷氨酸受体可调节这些细胞上的电压门控持续钙电流。
We have used electrophysiological, pharmacological and immunological techniques to determine which classes of metabotropic glutamate receptors exist on cone horizontal cells in the catfish retina. Patch-clamp recordings in acutely dissociated cone horizontal cells provide evidence that group I and III metabotropic glutamate receptors exist, and are linked to modulation of a voltage-gated calcium current. Group II metabotropic glutamate receptor agonists did not affect the calcium current. Immunocytochemical techniques were used to study the localization of metabotropic glutamate receptor subtypes found in the catfish retina. Antibodies raised against group I (metabotropic glutamate receptor 1α, metabotropic glutamate receptor 5), group II (metabotropic glutamate receptor 2/3) and group III (metabotropic glutamate receptor 6) metabotropic glutamate receptor subtypes were used to label acutely dissociated horizontal, bipolar and Müller cells. Results from immunostaining provide evidence that cone horizontal cells express group I (metabotropic glutamate receptor 1α, metabotropic glutamate receptor 5) and group III (metabotropic glutamate receptor 6), but not group II (metabotropic glutamate receptor 2/3) receptor subtypes, consistent with our electrophysiological results. Cone horizontal cells exposed to anti-metabotropic glutamate receptor 1α, 5 or 6 antibodies all demonstrated diffuse overall staining, with patches of dark immunostaining found on both dendritic processes and cell somata. In catfish bipolar cells, all four of the anti-metabotropic glutamate receptor antibodies stained the processes and cell bodies of bipolar cells homogeneously. There was no evidence for a group of bipolar cells that did not stain with the anti-metabotropic glutamate receptor antibodies, although the densest immunostaining occurred when bipolar cells were incubated with the anti-metabotropic glutamate receptor 6 antibody. Müller cells did not show immunostaining against any anti-metabotropic glutamate receptor antibody. Our non-immune controls confirmed that immunostaining was specific for the antigen, and immunoblots were performed to demonstrate the specificity of the antibodies in catfish retina. These results support the hypothesis that group I and III metabotropic glutamate receptor subtypes are found on catfish horizontal cells, and group I, II and III metabotropic glutamate receptor subtypes are expressed on catfish bipolar cells. The metabotropic glutamate receptors on catfish cone horizontal cells act to modulate the voltage-gated sustained calcium current found on these cells.