Figure 7.

Spinal sPLA₂ inhibition at day 7 returns evoked and spontaneous dorsal horn activity to sham levels on day 14 after painful nerve root injury. (a) Differences in dorsal horn evoked activity are only observed after a noxious pinch, with both the inhibitor-treated (*p = 0.005) and sham (#p = 0.0001) groups exhibiting significantly fewer evoked spikes than the vehicle-treated nerve root compression (NRC) group. (b) Both non-noxious and noxious filament stimulation also elicit significantly more evokes spikes for NRC with vehicle treatment than sham (#p < 0.004); yet, inhibitor treatment significantly reduces (*p < 0.026) evoked activity to sham levels. (c) Example voltage traces from vehicle-treated neurons that display no baseline firing (0 spikes/sec) or active firing (either <1 or ≥1 spike/sec). (d) Spinal sPLA₂ inhibition also restores the proportion of neurons that exhibit spontaneous activity to sham levels and is significantly different (*p = 0.038) than the proportion of neurons observed after NRC with vehicle treatment. At day 14, the proportion of neurons with spontaneous activity is also significantly different (#p = 0.006) in the vehicle NRC group than that in the sham control group.