Fig. 5

GluN1 receptors were involved in stress-induced wide-spreading hyperalgesia in female rats with orofacial pain. a The expression of GluN1 receptors in L4-L5 spinal dorsal horn in the E2 + CFA + FS group (n = 5) and oil + CFA + FS group (n = 5) significantly increased than that in the oil + saline + non-FS group (n = 5). § p < 0.05 vs the oil + saline + non-FS group. b NMDA receptor antagonist APV but not vehicle (saline) blocked the development of thermal hyperalgesia induced by stress in female rats with orofacial inflammation. *** p < 0.001 vs baseline. The thermal withdrawal latency significantly decreased on day 2 post FS stress in saline treated rats (E2 + CFA + FS + saline group, n = 12) compared with APV treated (E2 + CFA + FS + APV group, n = 8). # p < 0.05 vs the E2 + CFA + FS + APV group at the same time point. c APV but not vehicle blocked mechanical allodynia induced by stress in female rats with orofacial inflammation. *** p < 0.001 vs baseline. The mechanical withdrawal threshold significantly decreased on day 3 and day 7 post FS stress in saline treated rats (E2 + CFA + FS + saline group, n = 12) compared with APV treated (E2 + CFA + FS + APV group, n = 8). # p < 0.05 vs the E2 + CFA + FS + APV group at the same time point