Transgene is specifically and functionally expressed in retinal inhibitory interneurons in the VGAT-ChR2-EYFP mouse
Transgene is specifically and functionally expressed in retinal inhibitory interneurons in the VGAT-ChR2-EYFP mouse
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转基因在 VGAT-ChR2-EYFP 小鼠视网膜抑制性中间神经元中特异性、功能性表达
DOI：
10.1016/j.neuroscience.2017.09.006
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发表时间：
2017
期刊：
影响因子：
3.3
通讯作者：
Weng Shi Jun
中科院分区：
文献类型：
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作者：
Xu Guo Zhong;Cui Ling Jie;Liu Ai Lin;Zhou Wei;Gong Xue;Zhong Yong Mei;Yang Xiong Li;Weng Shi Jun
在各种转基因小鼠中已经报道了视网膜中的异位转基因表达，表明表征视网膜表型的重要性。我们通过荧光免疫组织化学和电生理学检查了VGAT-ChR 2-EYFP小鼠视网膜中的转基因表达，特别强调了通过特定标记物鉴定的视网膜神经元亚型中的增强型黄色荧光蛋白（EYFP）定位。在内、外丛状层均检测到较强的EYFP信号。此外，ChR 2-EYFP融合蛋白还在绝大多数抑制性中间神经元的胞体中表达，包括水平细胞和GABA能和甘氨酸能无长突细胞。然而，一小部分位于神经节细胞层的无长突细胞没有被EYFP标记，其中一部分是胆碱能细胞。相反，在视网膜兴奋性神经元的胞体中没有检测到EYFP信号：光感受器、双极细胞和神经节细胞以及Müller胶质细胞。当突触能传递被阻断时，明亮的蓝光刺激引起来自无长突细胞的内向光电流，以及来自神经节细胞的突触后抑制电流，表明功能性ChR 2表达。因此，当需要视网膜抑制性神经元的靶向标记和/或光遗传学操作时，VGAT-ChR 2-EYFP小鼠可以是用于解剖视网膜微电路的有用动物模型。
Ectopic transgene expression in the retina has been reported in various transgenic mice, indicating the importance of characterizing retinal phenotypes. We examined transgene expression in the VGAT-ChR2-EYFP mouse retina by fluorescent immunohistochemistry and electrophysiology, with special emphasis on enhanced yellow fluorescent protein (EYFP) localization in retinal neuronal subtypes identified by specific markers. Strong EYFP signals were detected in both the inner and outer plexiform layers. In addition, the ChR2-EYFP fusion protein was also expressed in somata of the great majority of inhibitory interneurons, including horizontal cells and GABAergic and glycinergic amacrine cells. However, a small population of amacrine cells residing in the ganglion cell layer were not labeled by EYFP, and a part of them were cholinergic ones. In contrast, no EYFP signal was detected in the somata of retinal excitatory neurons: photoreceptors, bipolar and ganglion cells, as well as Müller glial cells. When glutamatergic transmission was blocked, bright blue light stimulation elicited inward photocurrents from amacrine cells, as well as post-synaptic inhibitory currents from ganglion cells, suggesting a functional ChR2 expression. The VGAT-ChR2-EYFP mouse therefore could be a useful animal model for dissecting retinal microcircuits when targeted labeling and/or optogenetic manipulation of retinal inhibitory neurons are required.