Vesicle dynamics and synaptic computation. (360G-Wellcome-064413_Z_01_A)

This proposal aims to build a quantitative understanding of synaptic function by providing direct links between molecular mechanisms and synaptic computation. We will focus mainly on the cerebellar mossy fibre-granule cell synapse, a model system that is well suited for this purpose. A core aim is todevelop a high resolution optical assay of vesicular release by applying new confocal methods to acute slices from transgenic mice expressing synaptopHluorin. This and recent advances in patching presynaptic terminals will be used to characterize, systematically, vesicle supply, Ca2+-dependenceof release and vesicle recycling. A kinetic model of the vesicle cycle will bedeveloped to elucidate the key determinants of synaptic function. The molecular determinants of specific presynaptic processes will be identified bycomparing model predictions with the behaviour of synapses when protein interactions are altered in transgenic mice or with peptides. Postsynaptically, AMPA receptor function will be examined with localized glutamate uncaging. Key subsynaptic processes will be linked to function by