Competitive gel-based activity-based protein profiling (ABPP) reveals higher monoacylglycerol lipase (MAGL) activity over fatty acid amide hydrolase (FAAH) in trigeminal ganglia (TG) and cervical, thoracic and lumbar dorsal root ganglion (DRG). (A) Rat TG and DRG proteomes were preincubated for 1 h with vehicle (DMSO), the MAGL-inhibitors JJKK-048 (100 nM) and KML29 (1 μM) and FAAH-inhibitor JZP327A (1 μM). Then they were labeled with the fluorescent probe TAMRA-FP, as indicated in Materials and Methods. TAMRA-FP labeled bands (active serine hydrolases) appear dark after in-gel imaging. FAAH and MAGL were identified based on selective inhibition and their expected molecular weights. Notice that MAGL activity after DMSO treatment is high whereas the FAAH activity was almost absent. (B) Histograms comparing the basal activity of MAGL and FAAH in TG and DRG. Basal MAGL activity was approximately 9-fold higher compared that of FAAH in TG (in a.u., arbitrary units). Similarly, MAGL activity compared to that of FAAH was ~5-fold higher in cervical DRG, ~4-fold higher in thoracic DRG and ~11-fold higher in lumbar DRG. Unpaired t-test, *** p < 0.001, n = 8.