FIG. 3.

Plasma extracellular vesicles (EVs) enriched for neuronal origin, astrocyte, or oligodendrocyte origin. Schematic showing the assembly and release of EVs from cells within the brain. EVs are generated by the inward budding of endosomal membranes, with the associated recruitment and internalization of cellular protein and RNA cargo. Following their cellular release EVs travel within the interstitial fluid to neighboring cells or, via the circulation, to distant targets to potentially provide modulatory actions. EVs are found in and can be isolated from plasma/serum samples from animal models as well as humans. Enrichment for their cellular origin (whether neuronal, astrocyte, or a different cell type—such as oligodendrocytces) can be achieved by immunoprecipitation with biotinylated antibodies against surface markers to isolate sub-populations from different central nervous system (CNS) cell types. The quantitative evaluation of their protein and RNA content provides a platform for their use as biomarkers to changes in neurological function, disease state, and treatment conditions.