Figure 7. Impact SCI causes upregulation on the expression of a cluster of cell cycle genes in the hippocampus. Quantitative real-time PCR analysis was used to quantify mRNA levels in the hippocampal tissues from sham or SCI mice at 1 d, 7 d or 9 wk post-injury. The E2F1 transcription factor (A) showed a rapid, transient elevation at 24 h after injury. The expression of cyclin A1, A2, D1, and PCNA genes (B and C, E and F) were significantly increased in the SCI rats at 9 wk post-injury, whereas cyclin B1 remained unchanged at all time-points (D). *P < 0.05, **P < 0.01, ***P < 0.001 vs. Sham group. n = 4 (Sham), 6 (d1 SCI), 6 (d7 SCI), 5 (9 wk SCI).