Genetic studies in Drosophila: vesicle pools and cytoskeleton-based regulation of synaptic transmission.

Presynaptic plasticity mechanisms rely on modulation of the synaptic vesicle fusion machinery and the regulated mobilization of synaptic vesicles at the active zone. This review discusses recent evidence suggesting that the relative proportions of synaptic vesicles in the reserve and ready releasable pools is the primary determinant of synaptic transmission strength, and that transport of vesicles between these pools is mediated by cytoskeletal mechanisms. Recent efforts to identify the molecules required for regulation of the presynaptic cytoskeleton suggest that common mechanisms may exist to regulate synaptic vesicle pools in widely divergent neuronal types, ranging from synaptic modulation at the Drosophila neuromuscular junction to the synaptic plasticity required for learning and memory in the mammalian brain.