Fig. 1.

Rat spontaneous pain behavior recording photos (a) and rating score (b) after CCI surgery. Figure 1a is the rat affected hind paw photos of spontaneous pain behavior recording at 0, 3, 4, 5, 7, and 14 days. Figure 1b is the postoperative spontaneous pain behavior rating score. The score began to increase from the third day and reach the peak on the seventh day. It could sustain for 14 days until drawing the materials from rats. There was a especially significant difference between control groups and CCI group. **P < 0.01, compare to control group, n = 6