1. A method for the in vitro differentiation of mesenchymal stem cells and selection of neural precursors derived therefrom, the method comprising the steps of: (a) isolating mesenchymal stem cells from a human with multiple sclerosis, (b) expanding the isolated mesenchymal stem cells, (c) culturing a portion of said expanded mesenchymal stem cells in a neural progenitor basal medium (NPBM) supplemented with epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and neural cell survival factor-1 (NSF-1), (d) collecting floating cell clusters from the NPBM-cultured cells, (e) measuring, in a test portion of the collected cells, expression of nestin, glial fibrillary acidic protein (GFAP), neurofilament-M (NF-M), and alpha smooth muscle (aSM) actin, relative to expression of nestin, GFAP, NF-M, and aSM actin in a test portion of the mesenchymal stem cells expanded in step (b), and (f) selecting the remaining portion of the collected cells as neural precursors for further use based on increased expression of nestin, GFAP, and NF-M, and decreased expression of αSM actin in said test portion of the collected cells, relative to the expression of nestin, GFAP, NF-M, and aSM actin in said test portion of mesenchymal stem cells.