Tunneling nanotubes (TNTs), open membranous channels between connected cells, represent a novel direct way of communication between distant cells for the diffusion of various cellular material, including survival or death signals, genetic material, organelles, and pathogens. Their discovery prompted us to review our understanding of many physiological and pathological processes involving cellular communication but also allowed us to discover new mechanisms of communication at a distance. While this has enriched the field, it has also generated some confusion, as different TNT-like protrusions have been described, and it is not clear whether they have the same structure–function. Most studies have been based on low-resolution imaging methods, and one of the major problems is the inconsistency in demonstrating the capacity of these various connections to transfer material between cells belonging to different populations. This brief review examines the fundamental properties of TNTs. In adult tissues, TNTs are stimulated by different diseases, stresses, and inflammatory signals. ‘Moreover’, based on the similarity of the processes of development of synaptic spines and TNT formation, we argue that TNTs in the brain predate synaptic transmission, being instrumental in the orchestration of the immature neuronal circuit.

隧道纳米管 (TNT) 是连接细胞之间开放的膜通道，代表了远距离细胞之间一种新的直接通信方式，用于扩散各种细胞物质，包括生存或死亡信号、遗传物质、细胞器和病原体。他们的发现促使我们回顾了我们对涉及细胞通讯的许多生理和病理过程的理解，但也使我们能够发现新的远距离通讯机制。虽然这丰富了该领域，但也产生了一些混乱，因为已经描述了不同的 TNT 样突起，目前尚不清楚它们是否具有相同的结构功能。大多数研究是基于对低分辨率成像方法，主要问题之一是在证明这些不同连接在属于不同群体的细胞之间转移材料的能力时不一致。这篇简短的评论检查了 TNT 的基本特性。在成人组织中，TNT 受到不同疾病、压力和炎症信号的刺激。“此外”，基于突触棘和 TNT 形成过程的相似性，我们认为大脑中的 TNT 早于突触传递，有助于未成熟神经元回路的协调。