Myelin is repaired by constitutive differentiation of oligodendrocyte progenitors

Oligodendrocytes form myelin sheaths around axons to enable rapid
signaling within neural circuits. The generation of new oligodendrocytes
through differentiation of oligodendrocyte precursor cells (OPCs) promotes
myelin plasticity and repair in the adult brain. Here, we performed
genetic interrogation and in vivo analysis of OPCs in order to determine
their differentiation dynamics. Our results show that OPCs attempt to
differentiate throughout the adult CNS with spatial and temporal
regularity. The differentiation rate was not influenced by myelin demand
or oligodendrocyte loss, and declined with age and in response to acute
inflammation. The results suggest that OPC differentiation is governed
primarily by constitutive processes and might be negatively influenced by
aging and inflammation.