Oligodendrocyte precursor cells engulf synaptic inputs in an experience- and microglia-dependent manner

Oligodendrocyte precursor cells (OPCs) are a highly proliferative class of non-neuronal progenitors that largely give rise to myelinating oligodendrocytes. Although OPCs persist across the lifespan, their functions beyond oligodendrogenesis remain to be fully characterized. Here, we show that OPCs contribute to neural circuit remodeling by internalizing presynaptic thalamocortical inputs in both the developing and adult mouse visual cortex. Inputs internalized by OPCs localize to lysosomal compartments, consistent with OPC engulfment of synapses occuring through phagocytosis. We further show that engulfment by OPCs is heightened during experience-dependent plasticity, and that this experience-dependent increase in engulfment requires microglia. These data identify a new function for OPCs beyond the generation of oligodendrocytes and reveal that distinct non-neuronal populations collaborate to modulate synaptic connectivity.