Neuronal fusion mediated by soluble N-ethylmaleimide-sensitive-factor attachment protein receptors (SNAREs) is a fundamental cellular process by which two initially distinct membranes merge resulting in one interconnected structure to release neurotransmitters into the presynaptic cleft. To get access to the different stages of the fusion process, several in vitro assays have been developed. In this review, we provide a short overview of the current in vitro single vesicle fusion assays. Among those assays, we developed a single vesicle assay based on pore-spanning membranes (PSMs) on micrometre-sized pores in silicon, which might overcome some of the drawbacks associated with the other membrane architectures used for investigating fusion processes. Prepared by spreading of giant unilamellar vesicles with reconstituted t-SNAREs, PSMs provide an alternative tool to supported lipid bilayers to measure single vesicle fusion events by means of fluorescence microscopy. Here, we discuss the diffusive behaviour of the reconstituted membrane components as well as that of the fusing synthetic vesicles with reconstituted synaptobrevin 2 (v-SNARE). We compare our results with those obtained if the synthetic vesicles are replaced by natural chromaffin granules under otherwise identical conditions. The fusion efficiency as well as the different fusion states observable in this assay by means of both lipid mixing and content release are illuminated.

由可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体 (SNARE) 介导的神经元融合是一种基本的细胞过程，通过该过程，两个最初不同的膜合并，形成一个互连的结构，将神经递质释放到突触前间隙。为了了解融合过程的不同阶段，已经开发了几种体外测定法。在这篇综述中，我们对当前的体外单囊泡融合测定进行了简短的概述。在这些测定中，我们开发了一种基于硅微米级孔上的跨孔膜（PSM）的单囊泡测定，这可能克服与用于研究融合过程的其他膜结构相关的一些缺点。 PSM 通过用重建的 t-SNARE 铺展巨型单层囊泡来制备，为支持的脂质双层提供了一种替代工具，可通过荧光显微镜测量单囊泡融合事件。在这里，我们讨论了重建膜成分的扩散行为以及融合合成囊泡与重建突触短蛋白 2 (v-SNARE) 的扩散行为。我们将我们的结果与在其他相同条件下用天然嗜铬颗粒替换合成囊泡所获得的结果进行比较。阐明了融合效率以及在该测定中通过脂质混合和内容物释放可观察到的不同融合状态。