The Dichotomous Role of Extracellular Vesicles in the Central Nervous System

Extracellular vesicles (EVs) are important mediators of intercellular communication. Interest in the role of central nervous system (CNS)-derived EVs has been increasing; however, some skepticism of their importance has persisted because many aspects of their biology remain elusive. This ambiguity is largely due to technical barriers that hamper our ability to achieve a comprehensive understanding of their molecular components and mechanisms responsible for their transmission and uptake. However, accumulating evidence supports the notion that EVs play important roles in basic physiological processes within the CNS during neurodevelopment and synaptic plasticity. Interestingly, EVs also act to spread toxic polypeptides in neurodegenerative diseases. Developing a more profound understanding of the role that EVs play in the CNS could lead to the identification of biomarkers and potential vehicles for drug delivery. Here we highlight our current understanding of CNS EVs and summarize our current understanding of their complex role in the CNS.