Fig. 4

Behavioral responses of rhBMP-2/ACS or vehicle/ACS implanted rats to acute painful stimuli. Transient effects of rhBMP-2 in spinal arthrodesis model on withdrawal responses (presented as withdrawal latency) to noxious thermal stimulation (a ipsilateral and b contralateral; mean ± SEM, n = 11). Effects of rhBMP-2/ACS implantation on mechanical pain sensitivity as assessed with von Frey hair stimulation (c ipsilateral and d contralateral). Line graph presented as mean ± SEM of the log of the threshold von Frey hair bend force (mean ± SEM, n = 11). Statistical significance in a–d are represented as *p < 0.05, where comparisons are against pre-operative baseline for ipsilateral or contralateral or ^# p < 0.05 comparing different treatment groups at the same time point