Neurotrophin-3 specifically increases mature oligodendrocyte population and enhances remyelination after chemical demyelination of adult rat CNS

In human central nervous system (CNS) demyelinating diseases, spontaneous remyelination is often incomplete. Therefore, we have tested whether neutrotrophin-3 (NT-3) accelerates CNS myelin repair after a chemically-induced demyelination. One group of adult rats was inflected in the corpus callosum (CC) with 1 mul of 1% lysophosphatidylcholine (LPC) and 1 mul of NT-3 (1 mug/mul), and 15 days after injure, (D15) remyelination was compared to control rats (receiving 1 mul of LPC+1 mul of vehicle buffer of NT-3). The demyelinated volume decreased by 56% in NT-3-treated rats at D15. and immunohistochernistry showed an increase in mature MBP+ oligodendrocytes (OL) ( +66%) in treated animals (whereas less mature (CNP') OL were unchanged). Since less than 3% axons degenerate in this model, and as astrocytic gliosis was not modified, these data suggest that NT-3 acts directly on cells of the OL lineage to enhance remyelination in vivo. (C) 2003 Elsevier Science B.V. All rights reserved.