Western blots illustrating enhanced NMDA receptor phosphorylation and upregulation of GFAP levels in the trigeminal Vi/Vc transition zone and caudal Vc after masseter or skin inflammation. The examples of immunoreactive bands for phosphoserine896 NR1 subunit (P-NR1) of the NMDA receptor (A) and GFAP (B) are shown on top of each panel. CFA was injected into the masseter (Masseter-CFA) or the overlying skin site (Skin-CFA) to produce deep or cutaneous inflammation, respectively. Note that compared to naive and saline controls, masseter inflammation induced an increase in P-NR1 and GFAP levels in both Vi/Vc and caudal Vc at 30 min (30') and 24 h after CFA (Left). However, cutaneous inflammation only led to an increase in P-NR1 and GFAP levels in caudal Vc, but not in Vi/Vc transition zone (Right). *, p < 0.05; **, p < 0.01 vs. naive rats. N = 3-4 for each time point. Error bars represent S.E.M.