Fig. 2.

Quantitative assessment of immunostaining shows that systemic treatment with guanosine stimulates endogenous oligodendroglial progenitors (NG2+ cells) to proliferate and mature in rats with stable chronic spinal cord injury. a, b Bromodeoxyuridine (BrdU) was used to label proliferating cells after treatment. BrdU immunostaining in cross sections from vehicle- (a) and guanosine- (b) treated animals at the lesion 14 days after treatment shows increased BrdU+ nuclei in b compared to the vehicle-treated control group in a. Scale bar = 50 μm. c Quantitative analysis shows that 7 or 14 days after guanosine treatment there was a significant increase in the number of BrdU+ cells compared with vehicle-treated controls. d, e Demonstrate examples of double-fluorescent immunostaining using antibodies against BrdU (in green) and a marker (NG2) for oligodendroglial progenitors (in red) in cross sections from vehicle- (d) and guanosine- (e) treated animals at the lesion 14 days after treatment. Scale bar = 50 μm. f–h Show quantification of proliferating progenitors (NG2+/BrdU+ double-labelled cells; f) and total number of NG2 cells (g). Data indicate that after 7 or 14 days administration guanosine significantly stimulates proliferation of oligodendroglial progenitors (f, g). Concurrently, guanosine also significantly increases the number of mature oligodendroglia shown in i and j compared to vehicle-treated controls (h, j) using fluorescent immunostaining with a specific marker (Rip) to label the mature oligodendroglia. Scale bar = 50 μm