Cavity formation is progressive after chronic contusion and is attenuated by CDKs inhibition. SCI-induced lesion volume/cavity formation was measured with GFAP/DAB staining and analyzed by unbiased stereological techniques. (A) Representative images showed lesion cavity at 3 mm rostral to the injury center at 4 weeks (b) and 4 months (c) after SCI. Scale bars = 500 μm. (B) Histological assessment showed that 4 months-SCI rats developed a larger lesion cavity (52.4 ± 5.0% of total volume) than that in 4 weeks-SCI animals (28.4 ± 3.9% of total volume). Notably, a significant reduction in lesion volume was found in rats that received delayed systemic treatment of CR8 at 4 months post-injury (40.8 ± 3.6% of total volume). *p < 0.05 vs. SCI-4 weeks Veh group; #
p < 0.05 vs. SCI-4 months Veh group. n = 6 rats/group.