FLUORESCENCE ACTIVATED SYNAPTOSOME SORTING FROM PIONEERING TO CORE FACILITY AT BORDEAUX NEUROCAMPUS

The central nervous system contains a complex intermingled network of neurons, glia, and vascular cells. For several decades, neurobiologists have used technologies to isolate specific events occurring along these networks and analyze the underlying molecular mechanisms. To reduce this complexity, biochemists have optimized subcellular fractionation methods that enrich for specific compartments such as synapses (called “synaptosomes”). However, these approaches suffer from a lack of specificity and purity.
We thus extended the conventional synaptosome preparation by an upstream labelling of specific populations of synaptosomes using genetically encoded fluorescent reporters and a downstream fluorescence activated sorting step to remove unwanted contaminants as much as possible. To that end we first took advantage of the VGLUT1^venus knock-in mouse model that labels a major class of excitatory synapses. We then adapted our protocol to sort from single neuronal projections and small target regions of the brain as we did in the present example by labeling dopaminergic projections to the striatum. Along the years and projects, we developed a wide array of analysis methods taking advantage of the fluorescent synaptosome model.
With these assets, we now established a core facility to host custom designed biological microparticle sorting projects. Here we propose a detailed presentation of the Fluorescence Activated Microparticle Sorting: FAMS facility at Bordeaux Neurocampus with a strong emphasis on synaptosome sorting.