Kuromi H, Kidokoro Y
Institute for Behavioral Sciences, Gunma University School of Medicine, Maebashi, Japan.
Neuron. 2000 Jul;27(1):133-43. doi: 10.1016/s0896-6273(00)00015-5.
At Drosophila neuromuscular junctions, there are two synaptic vesicle pools, namely the exo/endo cycling pool (ECP) and the reserve pool (RP). We studied the recruitment process from RP using a fluorescent dye, FMI-43. During high-frequency nerve stimulation, vesicles in RP were recruited for release, and endocytosed vesicles were incorporated into both pools, whereas with low-frequency stimulation, vesicles were incorporated into and released from ECP. Release of vesicles from RP was detected electrophysiologically after emptying vesicles in the ECP of transmitter by a H+ pump inhibitor. Recruitment from RP was depressed by inhibitors of steps in the cAMP/PKA cascade and enhanced by their activators. In rutabaga (rut) with low cAMP levels, mobilization of vesicles from RP during tetanic stimulation was depressed, while it was enhanced in dunce (dnc) with high cAMP levels.
在果蝇神经肌肉接头处，存在两种突触小泡池，即外排/内吞循环池（ECP）和储备池（RP）。我们使用荧光染料FMI-43研究了从储备池的募集过程。在高频神经刺激期间，储备池中的小泡被募集用于释放，内吞的小泡被纳入两个池，而在低频刺激时，小泡被纳入外排/内吞循环池并从该池中释放。在用H⁺泵抑制剂排空递质外排/内吞循环池中的小泡后，通过电生理学方法检测到储备池中小泡的释放。cAMP/PKA级联反应步骤的抑制剂会抑制从储备池的募集，而其激活剂则会增强这种募集。在cAMP水平较低的rutabaga（rut）中，强直刺激期间储备池中小泡的动员受到抑制，而在cAMP水平较高的dunce（dnc）中则增强。
