The glutamate analog 2-amino-4-phosphonobutyrate antagonizes synaptic transmission from cones to horizontal cells in the goldfish retina.
The glutamate analog 2-amino-4-phosphonobutyrate antagonizes synaptic transmission from cones to horizontal cells in the goldfish retina.
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谷氨酸类似物 2-氨基-4-磷酸丁酸拮抗金鱼视网膜中从视锥细胞到水平细胞的突触传递。
DOI：
10.1073/pnas.86.5.1726
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发表时间：
1989
影响因子：
11.1
通讯作者：
Copenhagen,DR
中科院分区：
文献类型：
--
作者：
Nawy,S;Sie,A;Copenhagen,DR
在视网膜中，谷氨酸类似物 2-氨基-4-磷酸丁酸 (APB) 区分了一类谷氨酸受体，该受体被认为仅存在于去极化双极细胞 (DBC) 上。我们现在报道 APB 是金鱼视网膜中视锥细胞驱动的水平细胞的有效拮抗剂。 APB 使膜超极化至与钴林格氏电势相同的电位并阻止光响应。 APB 专门作用于视锥细胞通路，因为它对视杆细胞驱动的水平细胞没有影响。对水平细胞具有拮抗作用的最低有效 APB 浓度（约 2 µM）与对 DBC 具有激动作用的浓度相似。 APB 无法阻断外源谷氨酸或红藻氨酸对水平细胞的作用。我们认为 APB 对锥体水平细胞突触的作用是在不同于谷氨酸和红藻氨酸结合位点的位点介导的。因此，APB很可能作用于水平细胞突触谷氨酸受体的不同位点或位于视锥细胞本身的突触前受体。
In the retina, the glutamate analog 2-amino-4-phosphonobutyrate (APB) distinguishes a class of glutamate receptors that is thought to be found only on depolarizing bipolar cells (DBCs). We now report that APB is a potent antagonist of cone-driven horizontal cells in the goldfish retina. APB hyperpolarized the membrane to the same potential as cobalt Ringer's and blocked the light responses. APB acted specifically on the cone pathway, as it had no effect on rod-driven horizontal cells. The lowest effective APB concentration for antagonistic action on the horizontal cells (approximately 2 microM) was similar to the concentration for agonist action on DBCs. APB was not able to block the actions of exogenous glutamate or kainate on horizontal cells. We propose that the action of APB on the cone-horizontal cell synapse is mediated at a site that is distinct from the glutamate and kainate binding site. Therefore, APB is most probably acting at a different locus on the synaptic glutamatergic receptors of the horizontal cells or at presynaptic receptors located on the cones themselves.