Wu L G, Borst J G
Abteilung Zellphysiologie, Max-Planck-Institut für medizinische Forschung, Heidelberg, Germany.
Neuron. 1999 Aug;23(4):821-32. doi: 10.1016/s0896-6273(01)80039-8.
Recovery from synaptic depression is believed to depend mainly on replenishment of the releasable pool of vesicles. We observed that during recovery from depression in a calyx-type synapse, part of the releasable pool was replenished rapidly. Half recovery occurred within 1 s, even in the absence of residual calcium. Vesicles that had recently entered the releasable pool had a 7- to 8-fold lower release probability than those that had been in the pool for more than 30 s. These results suggest that the reduction in the release probability of releasable vesicles contributes greatly to the level of depression. How synapses maintain transmission during repetitive firing is in debate. We propose that during repetitive firing, accumulation of intracellular Ca2+ may facilitate release of the rapidly replenished but reluctant vesicles, making them available for sustaining synaptic transmission.
突触抑制的恢复被认为主要依赖于可释放囊泡池的补充。我们观察到，在花萼型突触从抑制状态恢复的过程中，部分可释放囊泡池迅速得到补充。即使在没有残余钙的情况下，半恢复在1秒内就会发生。最近进入可释放囊泡池的囊泡的释放概率比那些在池中超过30秒的囊泡低7至8倍。这些结果表明，可释放囊泡释放概率的降低对抑制水平有很大贡献。突触在重复放电期间如何维持传递仍存在争议。我们提出，在重复放电期间，细胞内Ca2+的积累可能促进快速补充但难以释放的囊泡的释放，使其可用于维持突触传递。
