Objective To explore the function of metabtrophic glutamate receptor subtype 5(mGluR5) in formalin-induced temporomandibular joint pain.Methods A total of 36 adult SD rats were randomly divided into 6 groups(n =6),including normal control group(no-treated),negative control group(Nacl 0.9% injection),formalin group(5% formalin injection),MPEP-1 group(5% formalin +1 mmoL/L of MPEP injection),MPEP-2 group(5% formalin +2.5 mmoL/L MPEP injection),MPEP-3 group(5% formalin +5 mmoL/L MPEP injection).The nociceptive...