Chow I, Young S H
Dev Biol. 1987 Aug;122(2):332-7. doi: 10.1016/0012-1606(87)90298-3.
Gap junctions, which are low-resistance intercellular pathways, may contribute to normal embryogenesis by allowing cell-to-cell passage of as yet unidentified regulatory or inductive signals. But little is known about the properties of newly formed single junctional channels which are the basis of the communicating junctions. Reported here are the first direct measurements of current passing through single junctional channels as they form. Individual pairs of embryonic Xenopus muscle cells in culture were manipulated into contact, allowing control of the onset time and area of cellular contact, and current was recorded with the patch clamp technique. The opening of single channels which pass current between the two cells at a conductance of about 100 pS was observed within minutes of cell-cell contact. The channels opened one-at-a-time, and once formed, remained open for long periods of time, with infrequent brief closures. This suggests that formation of electrical coupling between two cells proceeds by addition of single conducting junctional channels one channel-at-a-time.
缝隙连接是低电阻的细胞间通道，它可能通过允许尚未确定的调节或诱导信号在细胞间传递，从而对正常胚胎发育有所贡献。但是，对于作为通讯连接基础的新形成的单个连接通道的特性却知之甚少。本文报道了对单个连接通道形成时通过的电流进行的首次直接测量。将培养的非洲爪蟾胚胎肌肉细胞单个配对，使其相互接触，从而可以控制细胞接触的起始时间和接触面积，并使用膜片钳技术记录电流。在细胞间接触后的几分钟内，观察到单个通道在两个细胞之间以约100皮西门子的电导通过电流。通道一次打开一个，一旦形成，就会长时间保持打开状态，偶尔会短暂关闭。这表明两个细胞之间的电偶联是通过一次添加一个传导性连接通道来实现的。
