Fig. 5.

Glial-restricted precursors (GRPs) immunopurified from the E14 rat spinal cord differentiate into astrocytes rather than SCs 4 weeks following transplantation into EB lesions. Embryonic GRPs express the glial precursor antigens A2B5 and NG2 as assessed by FACS (A, B). In (A, B) the green plot represents unlabeled control cells while the purple plot represents the population of cells labeled with fluorescent antibody. Double-label immunohistochemistry for hPAP and GFAP shows that most GRPs differentiate into astrocytes 4 weeks after engraftment into EB lesions of the ventrolateral spinal cord (C–E). (C–E) The insets show the entire region of the VLF and the inner box designates the area shown at higher magnification. Unlike adult OPCs, GRPs do not co-label with the SC myelin protein P0 following engraftment into EB lesions (F–H). As evidenced by the presence of some endogenous SC remyelination (G), this particular animal was not irradiated. Similar results were obtained irrespective of whether or not animals received irradiation, with the exception that endogenous SCs were not observed within EB-X lesions (data not shown). Scale bar = 50 μm in (C–E); 28 μm in (F–H).