“…Changes in functional expression of P2X 3 receptors are closely related to inflammation, while CFA injections or chronic nerve compression and temporal mandibular joint disorders increase the expression of P2X 3 receptors ( Xu and Huang, 2002 ; Ambalavanar et al, 2005 ; Shinoda et al, 2005 ). Intrathecal injection of P2X 3 receptor agonist α, β -meATP enhances pain behavior ( Xiang et al, 2008 ), while intrathecal injection of P2X 3 receptor antagonist A-317491 or treatment with antisense P2X 3 receptor oligonucleotides significantly reduces formalin- or α, β -meATP injection-induced nociceptive behavior and nociceptive inflammatory response in DRG and spinal cord after partial sciatic nerve ligation, CFA adjuvant, formalin or α, β -meATP injection into the skin ( Barclay et al, 2002 ; Hemmings-Mieszczak et al, 2003 ; McGaraughty et al, 2003 ; Pissanetzky, 2016 ). In addition, inflammatory cytokines IL-1, IL-6, and TNF-α also contribute to the pathophysiology of chronic pain ( del Rey et al, 2012 ; Li et al, 2017 ; Yang et al, 2020 ).…”