Ludwin S K
Department of Pathology, Queen's University, Kingston, Ontario, Canada.
Adv Neurol. 1988;47:215-54.
Remyelination in the PNS is efficient, quick, and consistently found in all demyelinating diseases. Schwann cell proliferation in response to demyelination is rapid and prolific, and the numbers of Schwann cells generated are in excess of those required for adequate remyelination. This cell poses no limit to regenerative potential, and it can divide and remyelinate following numerous repetitive episodes. The Schwann cell generally has easy access to the denuded axons. The limiting factor to remyelination is the persistence of the demyelinating agent, be it directed at the myelin or secondarily through axonal disease. CNS remyelination differs in some respects. Although it has now become clear that it may occur in a variety of clinical and experimental situations, it is slower and often less complete than in the PNS. The limiting factors here include the nature of the demyelinating process, the regenerative potential of the oligodendrocyte, and the accessibility of the latter to the demyelinated axon. It is apparent that the oligodendrocyte is capable of some proliferation, but the time frame in which this can occur is more constrained than for the Schwann cell. Nevertheless the demonstration that the process occurs leads to increasing hope that clinically useful remyelination may be encouraged in the future either by more carefully controlling the extent of demyelination or by finding ways of stimulating oligodendrocyte proliferation and access to the axon.
周围神经系统（PNS）的髓鞘再生高效、迅速，且在所有脱髓鞘疾病中均能持续出现。雪旺细胞对脱髓鞘的反应迅速且大量增殖，产生的雪旺细胞数量超过了充分髓鞘再生所需的数量。这种细胞对再生潜力没有限制，并且在经历多次重复发作后仍能分裂并进行髓鞘再生。雪旺细胞通常很容易接触到裸露的轴突。髓鞘再生的限制因素是脱髓鞘因子的持续存在，无论是直接作用于髓鞘还是继发于轴索性疾病。中枢神经系统（CNS）的髓鞘再生在某些方面有所不同。尽管现在已经清楚它可能在各种临床和实验情况下发生，但它比周围神经系统的髓鞘再生更慢，而且往往更不完全。这里的限制因素包括脱髓鞘过程的性质、少突胶质细胞的再生潜力以及少突胶质细胞接触脱髓鞘轴突的难易程度。显然，少突胶质细胞能够进行一定程度的增殖，但其发生的时间框架比雪旺细胞更受限制。然而，髓鞘再生过程的证实让人们越来越有希望，未来通过更严格地控制脱髓鞘程度，或者找到刺激少突胶质细胞增殖并使其接触轴突的方法，可能会促进临床上有用的髓鞘再生。
