Myelin, a lipid membrane that wraps axons, enabling fast neurotransmission and metabolic support to axons, is conventionally thought of as a static structure that is set early in development. However, recent evidence indicates that in the central nervous system (CNS), myelination is a protracted and plastic process, ongoing throughout adulthood. Importantly, myelin is emerging as a potential modulator of neuronal networks, and evidence from human studies has highlighted myelin as a major player in shaping human behavior and learning. Here we review how myelin changes throughout life and with learning. We discuss potential mechanisms of myelination at different life stages, explore whether myelin plasticity provides the regenerative potential of the CNS white matter, and question whether changes in myelin may underlie neurological disorders.

髓磷脂是一种包裹轴突的脂质膜，可实现对轴突的快速神经传递和代谢支持，通常被认为是在发育早期设置的静态结构。然而，最近的证据表明，在中枢神经系统 (CNS) 中，髓鞘形成是一个长期且可塑的过程，贯穿整个成年期。重要的是，髓磷脂正在成为神经元网络的潜在调节剂，人类研究的证据表明髓磷脂是塑造人类行为和学习的主要参与者。在这里，我们回顾了髓磷脂在整个生命和学习过程中是如何变化的。我们讨论了不同生命阶段髓鞘形成的潜在机制，探索髓鞘可塑性是否提供了中枢神经系统白质的再生潜力，并质疑髓鞘的变化是否可能是神经系统疾病的基础。