Kuromi H, Kidokoro Y
Institute for Behavioral Sciences, Gunma University School of Medicine, Maebashi, Japan.
Neuron. 1998 May;20(5):917-25. doi: 10.1016/s0896-6273(00)80473-0.
In a temperature-sensitive Drosophila mutant, shibire, synaptic vesicles are completely depleted in nerve terminals after stimulation at 34 degrees C, but upon returning to 22 degrees C, endocytosis resumes. In this study, synaptic vesicles in the boutons of nerve terminals at the mutant neuromuscular junction were loaded with a fluorescent dye, FM1-43, during vesicle reformation at 22 degrees C after complete depletion at 34 degrees C. We found two distinct pools of synaptic vesicles, namely an exo/endo cycling pool, located in the periphery of the bouton, and a reserve pool, located in its center. Cytochalasin D treatment eliminated the reserve pool and reduced synaptic transmission evoked by high frequency stimulation. Thus, the reserve pool may play a crucial role for sustaining high frequency synaptic transmission.
在一种温度敏感型果蝇突变体“shibire”中，在34摄氏度刺激后，神经末梢中的突触小泡会完全耗尽，但回到22摄氏度时，内吞作用会恢复。在本研究中，在34摄氏度完全耗尽后于22摄氏度进行小泡重塑期间，用荧光染料FM1-43加载了突变体神经肌肉接头处神经末梢突触小体中的突触小泡。我们发现了两种不同的突触小泡池，即位于突触小体周边的外排/内吞循环池和位于其中心的储备池。细胞松弛素D处理消除了储备池，并减少了高频刺激诱发的突触传递。因此，储备池可能对维持高频突触传递起关键作用。
