Intra-articular anti-NGF immediately after FJD prevented the development of FJD-induced pain and spinal neuronal hyperexcitability. (A) The forepaw mechanical withdrawal threshold significantly decreased from baseline for FJD+veh at all times (p<0.001), with no change from baseline at any time in the FJD+anti-NGF, sham+veh, or sham+anti-NGF groups. The withdrawal threshold decreased for FJD+veh compared to FJD+anti-NGF (*p<0.015), sham+veh (#p<0.001), and sham+anti-NGF (‡p<0.001) at all days. (B) At day 7, the number of spikes evoked in spinal neurons by forepaw stimulation with 10g and 26g von Frey filaments significantly increased in the FJD+veh group compared to all other groups (*#‡p<0.012). There were no differences between FJD+anti-NGF, sham+veh, and sham+anti-NGF for any filament. (C) The pinch, but not brush, stimulus evoked significantly more spikes in the FJD+veh group than all others (*#‡p<0.001). (D) There was a significant effect of group on the proportion of WDR neurons (+p<0.005), with the largest number in the FJD+veh group. (E) Representative recordings show increased spikes evoked by the 10g, 26g, and pinch stimuli in the FJD+veh group compared to the other groups. FJD: facet joint distraction; NGF: nerve growth factor; WDR: wide dynamic range.