In conclusion, it is an emerging scenario that active zone components are transported by vesicular organelles which may be used as modular units in synapse formation in developing neuronal networks. In the future, the following questions may move into the center of this field of research: what exactly is the subcellular compartment where active zone components meet initially? Do all active zone components meet there? Which ones are incorporated later? How many distinct pathways for trafficking of active zone components exist? Moreover, how are CAZ-proteins transported in invertebrates and in specialized synapses such as ribbon synapses? How are PTVs transported in general and in distinct systems, how are they targeted to nascent synaptic sites? Furthermore, do PTVs really fuse with the plasma membrane during active zone formation? Which molecules are involved, how is this regulated? Finally, how are synaptogenesis and synaptic turnover mediated in the adult nervous system? Do PTVs contribute to plasticity of mature synapses?*
Was this article helpful?