[Oligodendroglial defect and insufficiency of remyelination during MS: anatomoclinical and experimental comparative study].

Introduction: The mechanisms responsible for the failure of remyelination during MS are poorly understood. We have analyzed in which way oligodendrocytes (OL) could be involved.

Methods: The number of remyelinated fiber per OL has been determined in 18 chronic MS lesions and compared to normal appearing white matter (NAWM), as well as in the center of lysophosphatidyl choline (LPC)-induced lesions in adult rats in which remyelination was accelerated by microinjection of neurotrophin-3 (NT-3).

Results: In chronic MS lesions and in LPC-induced lesions the number of myelinated fibers per OL was strongly decreased compared to NAWM and to animals treated with NT-3 respectively.

Conclusion: Our results suggest that the capacity of OL to remyelinate axons could be impaired, due to successive relapses, during MS.