ACTIVITY-DEPENDENT FLUORESCENT STAINING AND DESTAINING OF LIVING VERTEBRATE MOTOR-NERVE TERMINALS
ACTIVITY-DEPENDENT FLUORESCENT STAINING AND DESTAINING OF LIVING VERTEBRATE MOTOR-NERVE TERMINALS
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DOI：
10.1523/jneurosci.12-02-00363.1992
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发表时间：
1992-02-01
影响因子：
5.3
通讯作者：
BEWICK, GS
中科院分区：
文献类型：
--
作者：
BETZ, WJ;MAO, F;BEWICK, GS
来自几个物种的活的运动神经末梢可以以活性依赖的方式被某些苯乙烯基染料染色，例如RH 414、RH 795和一种新的染料FM 1 -43，它们可以独立于其他染料成像。 染料显然被困在回收的突触囊泡中。 在蛙胸皮肌中，在染料存在下刺激后，沿神经末梢的长度出现沿着规则分布的明亮荧光点。 这些斑点与突触后ACh受体很好地对齐，并且持续数小时，除非给予进一步的刺激，在这种情况下，斑点消失。 与染色一样，褪色需要释放递质，并在高刺激频率下在几分钟内逐渐进行（例如，30 Hz），并且同一末端中的荧光点以大约相同的速率消失。 我们认为，每个斑点是一个集群的数百个突触囊泡和染色的机制涉及的能力，染料分区可逆地进入外小叶的表面膜，而不能穿透整个膜厚度。 然后，在递质释放后的内吞过程中，染料分子被捕获在回收的突触囊泡膜中。 因此，染料使之有可能光学研究囊泡胞吐作用和回收活神经末梢在真实的时间，并应是有用的标记终端在各种制剂根据其活动水平。
Living motor nerve terminals from several species can be stained in an activity-dependent fashion by certain styryl dyes, such as RH414, RH795, and a new dye, FM1-43, which can be imaged independently of the others. The dyes evidently become trapped within recycled synaptic vesicles. In frog cutaneus pectoris muscle, bright fluorescent spots spaced regularly along the length of the nerve terminals appear after stimulation in the presence of the dye. The spots align well with postsynaptic ACh receptors and are persistent for many hours, unless further stimulation is given, in which case the spots disappear. Destaining, like staining, requires transmitter release and proceeds gradually over several minutes at high stimulus frequencies (e.g., 30 Hz), and fluorescent spots in the same terminal disappear at about the same rate. We suggest that each spot is a cluster of hundreds of synaptic vesicles and that the mechanism of staining involves the ability of the dyes to partition reversibly into the outer leaflet of surface membranes, without being able to penetrate the entire membrane thickness. Then, during endocytosis following transmitter release, dye molecules become trapped in recycled synaptic vesicle membranes. The dyes therefore make it possible optically to study vesicle exocytosis and recycling in living nerve terminals in real time, and should be useful for marking terminals in a variety of preparations according to their level of activity.