Eye Center, Renmin Hospital of Wuhan University, Eye Institute of Wuhan University, PR China.
Acta Histochem. 2013 Jan;115(1):42-7. doi: 10.1016/j.acthis.2012.03.005. Epub 2012 Apr 16.
N-methyl-D-aspartate receptors (NMDARs) belong to the ionotropic glutamate receptors, which play key roles in neuronal communication in the retina. NMDA receptors are tetrameric protein complexes usually comprising two obligatory NMDA receptor 1 (NR1) subunits and modulatory NMDA receptor 2/3 (NR2/3) subunits. Although the expression patterns of different NMDA receptor subunits have been extensively studied, in this study we focused on NR1 protein expression in the rat retina by immunofluorescence double labeling. We show that NR1 labeling is diffusely distributed in the outer plexiform layer (OPL) and throughout the whole inner plexiform layer (IPL). The NR1-immunoreactivity (IR) was displayed in a variety of cells in the inner nuclear layer (INL) and the ganglion cell layer (GCL). Interestingly, NR1 was expressed in both rod and cone bipolar cells identified by specific bipolar cell markers Chx10, protein kinase C (PKC) and recoverin. All the amacrine cells that we studied, including cholinergic, dopaminergic, GABAergic and glycinergic amacrine cells, were NR1-IR positive. In the ganglion cell layer, NR1-IR was expressed in all cells that were positive for the ganglion cell marker Brn3a. Our study suggests that the NR1 subunit is expressed more widely than was previously appreciated.
N-甲基-D-天冬氨酸受体（NMDARs）属于离子型谷氨酸受体，在视网膜神经元通讯中发挥关键作用。NMDA 受体是四聚体蛋白复合物，通常由两个必需的 NMDA 受体 1（NR1）亚基和调节性 NMDA 受体 2/3（NR2/3）亚基组成。尽管不同 NMDA 受体亚基的表达模式已得到广泛研究，但在本研究中，我们通过免疫荧光双重标记重点研究了大鼠视网膜中的 NR1 蛋白表达。我们表明，NR1 标记在外部丛状层（OPL）和整个内部丛状层（IPL）中广泛分布。NR1-免疫反应性（IR）在内核层（INL）和节细胞层（GCL）中的多种细胞中显示。有趣的是，NR1 在由特定双极细胞标记物 Chx10、蛋白激酶 C（PKC）和恢复蛋白鉴定的杆状和锥状双极细胞中均有表达。我们研究的所有无长突细胞，包括胆碱能、多巴胺能、GABA 能和甘氨酸能无长突细胞，均为 NR1-IR 阳性。在节细胞层中，NR1-IR 在所有 Brn3a 阳性的节细胞中表达。我们的研究表明，NR1 亚基的表达比以前认为的更为广泛。
