Hartveit E, Brandstätter J H, Sassoè-Pognetto M, Laurie D J, Seeburg P H, Wässle H
Max-Planck-Institut für Hirnforschung, Neuroanatomische Abteilung, Frankfurt, Federal Republic of Germany.
J Comp Neurol. 1994 Oct 22;348(4):570-82. doi: 10.1002/cne.903480407.
The localization of the N-methyl-D-aspartate receptor subunit NR2A was studied, by using light microscopic immunocytochemistry, in the retina of adult rat, rabbit, cat, and monkey. Strong, punctate immunolabeling was observed in the inner plexiform layer indicating a synaptic localization of the NR2A subunit. The punctate labeling was concentrated in two bands corresponding to the on- and off-sublaminae of the inner plexiform layer. The punctate character of immunofluorescence suggested a synaptic localization of the receptor. This was confirmed by electron microscopy of immunostained adult rat retina. The staining was localized postsynaptic to cone bipolar cells, and only one of the two postsynaptic elements of the dyad was labeled. Staining was not observed at extrasynaptic plasma membranes. In situ hybridization of adult rat retina showed expression of the NR2A subunit in virtually all ganglion cells and displaced amacrine cells in the ganglion cell layer and in a subset of amacrine cells in the inner nuclear layer. The postnatal developmental expression of the NR2A subunit was studied in rat retina by light microscopic immunocytochemistry. Punctate immunolabeling appeared prior to eye opening, and the developmental profile of NR2A could be compatible with a role in development of circuitry in the inner plexiform layer.
利用光学显微镜免疫细胞化学技术，对成年大鼠、兔、猫和猴视网膜中N-甲基-D-天冬氨酸受体亚基NR2A的定位进行了研究。在内网状层观察到强烈的点状免疫标记，表明NR2A亚基定位于突触。点状标记集中在与内网状层的ON和OFF亚层相对应的两条带中。免疫荧光的点状特征表明该受体定位于突触。成年大鼠视网膜免疫染色的电子显微镜检查证实了这一点。染色定位于视锥双极细胞的突触后，并且双联体的两个突触后元件中只有一个被标记。在突触外质膜未观察到染色。成年大鼠视网膜的原位杂交显示，NR2A亚基在神经节细胞层的几乎所有神经节细胞和移位无长突细胞以及内核层的一部分无长突细胞中表达。通过光学显微镜免疫细胞化学技术研究了大鼠视网膜中NR2A亚基的出生后发育表达。点状免疫标记在睁眼之前出现，并且NR2A的发育情况可能与内网状层神经回路的发育作用相符。
