Characterization of green fluorescent protein-expressing retinal cells in CD 44-transgenic mice
Characterization of green fluorescent protein-expressing retinal cells in CD 44-transgenic mice
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DOI：
10.1016/j.neuroscience.2006.09.061
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发表时间：
2007-02-09
期刊：
影响因子：
3.3
通讯作者：
Dudley, V. J.
中科院分区：
文献类型：
--
作者：
Sarthy, V.;Hoshi, H.;Dudley, V. J.
视网膜中的感觉信息从杆状和锥状光感受器传递到更高的视觉中心，通过许多平行的电路独立地采样光感受器马赛克。每个回路由神经节细胞、双极细胞和无突细胞类型的独特组合组成。许多无毛细胞的形态和生理反应已经被描述。然而，它们参与的突触连接和视网膜回路却很少被理解。阻碍视网膜电路更全面表征的一个主要问题是需要对50多种视网膜内细胞类型进行特定的细胞标记。标记细胞的一种潜在策略是在特定细胞类型中使用转基因报告基因的表达。在最近对CD44增强绿色荧光蛋白（EGFP）转基因小鼠的研究中，我们观察到绿色荧光蛋白（GFP）在细胞核内层（INL）和GCL的无毛细胞和神经节细胞群体中表达。为了表征gfp标记细胞的形态，我们利用视网膜的整个载体进行靶向离子导入注射路西法黄和神经生物素。此外，免疫细胞化学用于表征细胞的抗原特性。我们发现许多表达gfp的细胞既能表达gaba，也能表达calretinin。除体细胞染色外，在内层丛状层（IPL）约50-60%的深度有一个较强的GFP（+）带。胆碱乙酰转移酶（choline acetyltransferase, ChAT）抗体双标记显示gfp条带位于视网膜内3层。在INL中标记效果最好的表达gfp的细胞类型是在第3层分叉的宽视场无毛细胞。gfp在GCL中的表达细胞类似于131型，也可能是A2神经节细胞。CD44-EGFP小鼠可为小鼠视网膜无突细胞的电生理和连接研究提供有价值的资源。(c) 2006 IBRO。Elsevier Ltd.出版。版权所有。
Sensory information in the retina is transferred from rod and cone photoreceptors to higher visual centers via numerous parallel circuits that sample the photoreceptor mosaic independently. Each circuit consists of a unique combination of ganglion cell, bipolar and amacrine cell types. The morphology and physiological responses of many amacrine cells have been characterized. However, the synaptic connections and retinal circuits in which they participate are only rarely understood. A major problem that has prevented fuller characterization of retinal circuitry is the need for specific cellular markers for the more than 50 inner retinal cell types. One potential strategy for labeling cells is to use transgenic expression of a reporter gene in a specific cell type. In a recent study of cluster of differentiation 44 (CD44)-enhanced green fluorescent protein (EGFP) transgenic mice, we observed that the green fluorescent protein (GFP) was expressed in a population of amacrine and ganglion cells in the inner nuclear layer (INL) and the GCL. To characterize the morphology of the GFP-labeled cells, whole mount preparations of the retina were used for targeted iontophoretic injections of Lucifer Yellow and Neurobiotin. Furthermore, immunocytochemistry was used to characterize the antigenic properties of the cells. We found that many GFP-expressing cells were GABAergic and also expressed calretinin. In addition to the somatic staining, there was a strong GFP(+)-band located about 50-60% depth in the inner plexiform layer (IPL). Double labeling with an antibody to choline acetyltransferase (ChAT) revealed that the GFP-band was located at strata 3 inner retina. The best-labeled GFP-expressing cell type in the INL was a wide-field amacrine cell that ramified in stratum 3. The GFP-expressing cells in the GCL resemble the type 131, or possibly A2 ganglion cells. The CD44-EGFP mice should provide a valuable resource for electrophysiological and connectivity studies of amacrine cells in the mouse retina. (c) 2006 IBRO. Published by Elsevier Ltd. All rights reserved.