Expression of alpha 7 nicotinic acetylcholine receptors by bipolar, amacrine, and ganglion cells of the rabbit retina
Expression of alpha 7 nicotinic acetylcholine receptors by bipolar, amacrine, and ganglion cells of the rabbit retina
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DOI：
10.1369/jhc.6a7116.2006
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发表时间：
2007-05-01
影响因子：
3.2
通讯作者：
Keyser, Kent T.
中科院分区：
文献类型：
--
作者：
Dmitrieva, Nina A.;Strang, Christianne E.;Keyser, Kent T.
胆碱能药物通过激活尼古丁乙酰胆碱受体（nachr）影响哺乳动物视网膜中许多神经节细胞（GCs）的光反应。虽然兔视网膜中表达含有β 2亚基的nAChR的视网膜神经元已被表征，但其他nAChR亚型的表达模式尚不清楚。因此，我们通过单标、双标和三标免疫组织化学方法评估了α 7 nachr在视网膜神经元中的表达。我们的数据表明，在兔视网膜中，几种类型的双极细胞、无腺细胞和GC层细胞表达α 7 nachr。至少有三种不同的锥体双极细胞群表现出α 7标记，而甘氨酸免疫反应性无毛细胞包括大多数α 7阳性无毛细胞。一些gaba能无分泌细胞也表现出α 7免疫反应性；在杆状双极细胞或杆状无毛细胞（所有无毛细胞）中未检测到α 7标记。我们的数据表明，乙酰胆碱（ACh）或胆碱激活α 7 nachr可能会影响几种类型的锥体双极细胞的谷氨酸释放，从而调节GC反应。乙酰胆碱诱导的抑制性无毛分泌细胞的兴奋可能引起其他无毛分泌和GC回路的抑制或去抑制。最后，乙酰胆碱可能作用于GCs自身表达的α 7 nachr。
Cholinergic agents affect the light responses of many ganglion cells (GCs) in the mammalian retina by activating nicotinic acetylcholine receptors (nAChRs). Whereas retinal neurons that express beta 2 subunit-containing nAChRs have been characterized in the rabbit retina, expression patterns of other nAChR subtypes remain unclear. Therefore, we evaluated the expression of alpha 7 nAChRs in retinal neurons by means of single-, double-, and triple-label immunohistochemistry. Our data demonstrate that, in the rabbit retina, several types of bipolar cells, amacrine cells, and cells in the GC layer express alpha 7 nAChRs. At least three different populations of cone bipolar cells exhibited alpha 7 labeling, whereas glycine-immunoreactive amacrine cells comprised the majority of alpha 7-positive amacrine cells. Some GABAergic amacrine cells also displayed alpha 7 immunoreactivity; alpha 7 labeling was never detected in rod bipolar cells or rod amacrine cells (All amacrine cells). Our data suggest that activation of alpha 7 nAChRs by acetylcholine (ACh) or choline may affect glutamate release from several types of cone bipolar cells, modulating GC responses. ACh-induced excitation of inhibitory amacrine cells might cause either inhibition or disinhibition of other amacrine and GC circuits. Finally, ACh may act on alpha 7 nAChRs expressed by GCs themselves.