Kántor Orsolya, Szarka Gergely, Benkő Zsigmond, Somogyvári Zoltán, Pálfi Emese, Baksa Gábor, Rácz Gergely, Nitschke Roland, Debertin Gábor, Völgyi Béla
Department of Neuroanatomy, Faculty of Medicine, Institute for Anatomy and Cell Biology, Albert-Ludwigs-University Freiburg, Freiburg, Germany.
MTA-PTE NAP 2 Retinal Electrical Synapses Research Group, Pécs, Hungary.
Front Cell Neurosci. 2018 Nov 22;12:409. doi: 10.3389/fncel.2018.00409. eCollection 2018.
Connexin36 (Cx36) subunits form gap junctions (GJ) between neurons throughout the central nervous system. Such GJs of the mammalian retina serve the transmission, averaging and correlation of signals prior to conveying visual information to the brain. Retinal GJs have been exhaustively studied in various animal species, however, there is still a perplexing paucity of information regarding the presence and function of human retinal GJs. Particularly little is known about GJ formation of human retinal ganglion cells (hRGCs) due to the limited number of suitable experimental approaches. Compared to the neuronal coupling studies in animal models, where GJ permeable tracer injection is the gold standard method, the post-mortem nature of scarcely available human retinal samples leaves immunohistochemistry as a sole approach to obtain information on hRGC GJs. In this study Lucifer Yellow (LY) dye injections and Cx36 immunohistochemistry were performed in fixed short-post-mortem samples to stain hRGCs with complete dendritic arbors and locate dendritic Cx36 GJs. Subsequent neuronal reconstructions and morphometric analyses revealed that Cx36 plaques had a clear tendency to form clusters and particularly favored terminal dendritic segments.
连接蛋白36（Cx36）亚基在整个中枢神经系统的神经元之间形成缝隙连接（GJ）。哺乳动物视网膜的此类缝隙连接在将视觉信息传递至大脑之前，负责信号的传递、平均和关联。视网膜缝隙连接已在多种动物物种中得到详尽研究，然而，关于人类视网膜缝隙连接的存在和功能，仍然存在令人困惑的信息匮乏。由于合适的实验方法有限，对于人类视网膜神经节细胞（hRGC）的缝隙连接形成尤其知之甚少。与动物模型中的神经元耦合研究相比，在动物模型中，注射缝隙连接可渗透示踪剂是金标准方法，而人类视网膜样本稀缺且具有死后性质，这使得免疫组织化学成为获取hRGC缝隙连接信息的唯一途径。在本研究中，对固定的死后短时间样本进行了荧光黄（LY）染料注射和Cx36免疫组织化学，以对具有完整树突分支的hRGC进行染色，并定位树突状Cx36缝隙连接。随后的神经元重建和形态计量分析表明，Cx36斑块明显倾向于形成簇，并且特别青睐树突末端节段。
