Myelin plasticity: sculpting circuits in learning and memory

Oligodendrocyte lineage cells have recently been shown to exhibit plasticity in response to sensory experience and learning. In this Review, Xin and Chan outline the evidence for and the possible mechanisms underlying the contribution of oligodendrocyte and myelin plasticity to memory acquisition and maintenance. Throughout our lifespan, new sensory experiences and learning continually shape our neuronal circuits to form new memories. Plasticity at the level of synapses has been recognized and studied for decades, but recent work has revealed an additional form of plasticity - affecting oligodendrocytes and the myelin sheaths they produce - that plays a crucial role in learning and memory. In this Review, we summarize recent work characterizing plasticity in the oligodendrocyte lineage following sensory experience and learning, the physiological and behavioural consequences of manipulating that plasticity, and the evidence for oligodendrocyte and myelin dysfunction in neurodevelopmental disorders with cognitive symptoms. We also discuss the limitations of existing approaches and the conceptual and technical advances that are needed to move forward this rapidly developing field.