Neuronal communication is typically mediated via synapses and gap junctions. New forms of intercellular communication, including nanotubes (NTs) and extracellular vesicles (EVs), have been described for non-neuronal cells, but their role in neuronal communication is not known. Recently, transfer of cytoplasmic material between donor and host neurons (“material transfer”) was shown to occur after photoreceptor transplantation. The cellular mechanism(s) underlying this surprising finding are unknown. Here, using transplantation, primary neuronal cultures and the generation of chimeric retinae, we show for the first time that mammalian photoreceptor neurons can form open-end NT-like processes. These processes permit the transfer of cytoplasmic and membrane-bound molecules in culture and after transplantation and can mediate gain-of-function in the acceptor cells. Rarely, organelles were also observed to transfer. Strikingly, use of chimeric retinae revealed that material transfer can occur between photoreceptors in the intact adult retina. Conversely, while photoreceptors are capable of releasing EVs, at least in culture, these are taken up by glia and not by retinal neurons. Our findings provide the first evidence of functional NT-like processes forming between sensory neurons in culture and in vivo.

中文翻译：

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类似纳米管的过程促进光感受器之间的物质转移


神经元通讯通常通过突触和间隙连接介导。细胞间通讯的新形式，包括纳米管（NT）和细胞外囊泡（EV），已被描述用于非神经元细胞，但它们在神经元通讯中的作用尚不清楚。最近，供体和宿主神经元之间细胞质物质的转移（“物质转移”）被证明在光感受器移植后发生。这一令人惊讶的发现背后的细胞机制尚不清楚。在这里，通过移植、原代神经元培养和嵌合视网膜的生成，我们首次证明哺乳动物感光神经元可以形成开放式 NT 样过程。这些过程允许细胞质和膜结合分子在培养物中和移植后转移，并且可以介导受体细胞的功能获得。极少数情况下，也观察到细胞器发生转移。引人注目的是，嵌合视网膜的使用表明，完整的成人视网膜中的光感受器之间可以发生物质转移。相反，虽然光感受器能够释放EV，至少在培养物中，但这些EV被神经胶质细胞而不是视网膜神经元吸收。我们的研究结果提供了在培养物和体内感觉神经元之间形成功能性 NT 样过程的第一个证据。