Carl Ludwig Institute of Physiology, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany.
J Neurosci. 2011 Apr 20;31(16):6041-52. doi: 10.1523/JNEUROSCI.6698-10.2011.
How can synapses change the amount of neurotransmitter released during synaptic plasticity? Although release in general is intensely investigated, its determinants during plasticity are still poorly understood. As a model for plastic strengthening of synaptic release, we here use the well-established presynaptic homeostatic compensation during interference with postsynaptic glutamate receptors at the Drosophila neuromuscular junction. Combining short-term plasticity analysis, cumulative EPSC analysis, fluctuation analysis, and quantal short-term plasticity modeling, we found an increase in the number of release-ready vesicles during presynaptic strengthening. High-resolution light microscopy revealed an increase in the amount of the active zone protein Bruchpilot and an enlargement of the presynaptic cytomatrix structure. Furthermore, these functional and structural alterations of the active zone were not only observed after lifelong but already after minutes of presynaptic strengthening. Our results demonstrate that presynaptic plasticity can induce active zone remodeling, which regulates the number of release-ready vesicles within minutes.
在突触可塑性过程中，突触如何改变神经递质的释放量？尽管目前对释放过程进行了深入研究，但对其在可塑性过程中的决定因素仍知之甚少。作为突触释放可塑性增强的模型，我们在此使用在果蝇肌神经接点中干扰突触后谷氨酸受体后的已建立的突触前内在稳态补偿。通过结合短期可塑性分析、累积 EPSC 分析、波动分析和量子短期可塑性建模，我们发现突触前增强过程中，准备释放的囊泡数量增加。高分辨率的荧光显微镜显示，活性区蛋白 Bruchpilot 的含量增加，并且突触前细胞基质结构增大。此外，这些活性区的功能和结构改变不仅在终生观察到，而且在几分钟的突触前增强后即可观察到。我们的研究结果表明，突触前可塑性可以诱导活性区重塑，在几分钟内调节准备释放的囊泡数量。
