Local Signaling for Tight Coupling of Synaptic Exo- and Endocytosis
In the CNS communication between neurons occurs at synapses by secretion of neurotransmitter via exocytosis of synaptic vesicles (SVs). Given the limited number of SVs in presynaptic boutons a fast and efficient trafficking cycle is required. Within this CRC we use cultured mammalian hippocampal neurons in conjunction with high and superresolution imaging methods to understand how local membrane signaling platforms orchestrate resorting and recycling of exocytosed SV proteins and lipids for proper SV reformation: We aim at answering the following central questions: Do SV proteins / lipids in part remain clustered after exocytosis, thereby facilitating formation of pre-assembled endocytic structures at the endocytic zone? To what extent do self-assembly forces between SV proteins/lipids function in maintaining endocytic domains (readily retrievable pool at endocytic sites)? What couples so tightly exo- and compensatory endocytosis despite their clear separation in two membrane domains?