Fig. 4. Representative photomicrograph showing the effect of intrathecal ketorolac on spinal cFos expression. There is a significant decrease in cFos immunostaining with 50 μg ketorolac treatment (A ) compared with saline (B ) in the deep dorsal horn region; similar differences were present in the central canal region (lamina X), (C ) = 50 μg ketorolac, (D ) = saline.