Synaptic vesicle pools and vesicle recycling in nerve terminals

神经末梢的突触小泡池和小泡回收

• 批准号: 10680760
• 负责人: KUROMI Hiroshi
• 金额: $ 2.18万
• 依托单位: Gunma University, School of Medicine, Institute for Behavioral Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10680760/
• 关键词: synaptic vesicles; FM1-43; exo; endo cycling pool; reserve pool; stimulation frequency; cAMP; PKA cascade; rutabaga; dunce; quantal content; forskolin; cyclosporin A

In a temperature-sensitive Drosophila mutant, shibire, synaptic vesicles are completely depleted in nerve terminals after stimulation at 34゜C, but upon returning to 22゜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゜C after complete depletion at 34゜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. To determine the role of exo/endo cycling vesicle pool in synaptic transmission, we estimated the quantal content electrophysiologically while the pool size was determined optically using fluorescent dye … More FM1-43. We then manipulated the size of the pool with following treatments. First, to change the state of boutons of terminals motoneuronal axons were severed. With this treatment the size of exo/endo cycling vesicle pool decreased together with the quantal content. Secondly, we promoted the FM1-43 uptake using cyclosporin A which inhibits calcineurin activities and enhances endocytosis. Cyclosporin A increased the total uptake of FM1-43, but neither the size of exo/endo cycling vesicle pool nor the quantal content changed . Thirdly, we increased the size of exo/endo cycling vesicle pool by forskolin which enhances synaptic transmission. The forskolin-treatment increased both the size of exo/endo cycling vesicle pool and the quantal content. Thus, we found that the quantal content was closely correlated with the size of exo/endo cycling vesicle pool but not necessarily with the total uptake of FM1-43 fluorescence by boutons. The results suggest that vesicles in the exo/endo cycling pool primarily participate in evoked exocytosis of vesicles. Less

在温度敏感的果蝇突变体中，shibire，在34°C下刺激后，合成蔬菜在神经末端完全耗尽，但在恢复22°C的内吞作用恢复后。在这项研究中，在34°C完全部署后，在22°C的场地报告中，将突变神经肌肉连接的神经末端的胸子中的合成蔬菜加载。我们发现了两个不同的突触蔬菜池，即一个位于Bouton的外围和一个位于其中心的储备池的Exo/Exo/endo骑自行车池。细胞切拉斯蛋白D处理消除了储备池，并减少了高频刺激引起的合成传播。该储备池对于维持高频合成传输可能起着至关重要的作用。为了确定EXO/ENDO循环场所在突触传输中的作用，我们在电生理上估计了定量含量，而使用荧光染料则通过光学确定池大小…更多的FM1-43。然后，我们通过以下处理来操纵游泳池的大小。首先，要改变末端的胸腔胸腔轴突的状态很严重。通过这种处理，Exo/endo循环囊泡池的大小随数量含量的降低。其次，我们使用环孢菌素A促进了FM1-43的吸收，从而抑制钙调蛋白活性并增强内吞作用。环孢菌素A增加了FM1-43的总吸收，但是Exo/endo Cycling囊泡池的大小均未改变，也没有改变数量含量。第三，我们通过Forskolin提高了Exo/endo循环囊泡池的大小，从而增强了突触传播。 Forskolin-Greatment增加了Exo/endo循环囊泡池的大小和数量含量。这就是我们发现，数量含量与Exo/endo循环蔬菜池的大小密切相关，但与Boutons的FM1-43荧光的总吸收相关。结果表明，Exo/endo骑自行车池中的蔬菜主要参与诱发蔬菜的胞吞作用。较少的

项目成果

Zhang,D,Kuromi,H.and Kibokoro,Y.: "Activation of metabotropic receptors enhances synaptic transmission at the Drosophila neuromuscular junction"Neuropharmacol.. 38. 645-657 (1999)

张，D，Kuromi，H. 和 Kibokoro，Y.：“代谢型受体的激活增强果蝇神经肌肉接头处的突触传递”Neuropharmacol.. 38. 645-657 (1999)

Zhang, D., Kuromi, H. and Kidokoro, Y.: "Synaptic transmission at the Drosophila neuromuscular junction : Effects of metabotropic glutamate receptor activation.""Slow synaptic response and modulation" Eds. by Kuba, K. et al. Springer-Velag, Tokyo.. 260-26

张，D.，Kuromi，H. 和 Kidokoro，Y.：“果蝇神经肌肉接头处的突触传递：代谢型谷氨酸受体激活的影响”。“慢速突触反应和调节”编辑。

Zhang D.,Kuromi H.and Kidokoro Y.: "Synaptic transmission at the Drosophila neuromuscular junction : Effects of metabotropic glutamate receptor activation"Slow synaptic glutamate receptor and modulation Edited by Kuba K.et al. Springer-Verlag, Tokyo. 260-

张D.，Kuromi H.和Kidokoro Y.：“果蝇神经肌肉接头处的突触传递：代谢型谷氨酸受体激活的影响”慢突触谷氨酸受体和调节由Kuba K.等人编辑。

Yoshihara,M.,Ueda,A.,Zhang,D.,Deitcher.D.L.Schwarz,T.L.and Kidokoro,Y.: "Selective effects of neuronal-synaptobrevin mutation on transmitter release evoked by sustained versus transient Ca^<2+> increases and by cAMP"J.Neurosci.. 19. 2432-2441 (1999)

Yoshihara,M.、Ueda,A.、Zhang,D.、Deitcher.D.L.Schwarz,T.L. 和 Kidokoro,Y.：“神经元突触短蛋白突变对持续与瞬时 Ca^2 > 引起的递质释放的选择性影响增加和

Rheuben, M.B., Yoshihara, M. and Kidokoro, Y.: "Ultrastructural correlations of neuromuscular junction development."Intern. Rev. Neurobiol.. 43. 69-9 (1999)

Rheuben, M.B.、Yoshihara, M. 和 Kidokoro, Y.：“神经肌肉接头发育的超微结构相关性。”实习生。