Communication between neurons relies on neurotransmission, a process during which synaptic vesicles containing neurotransmitters, are docked, primed and then fuse with the presynaptic plasma membrane thereby releasing the neurotransmitter on the post-synaptic neurons. The proteins involved in these mechanisms are constantly subjected to Brownian movement and hence must be organised in functional nanoclusters to optimise efficiency. How the inherent mobility of these proteins is compatible with docking, priming and ultimately fusion, is still subject to numerous investigations. In this talk, we will highlight key changes in the nanoscale organization of the SM-protein Munc18-1 and SNARE protein syntaxin1A, that are associated with neurotransmitter release.