Abstract:

 Objective   To explore the roles of cycclooxygenase-2 (COX-2) and proinflammatory cytokine lipopolysaccharide (LPS) in spinal long-term potentiation (LTP). Methods   The C-fiber-evoked field potentials were recorded at superficial layers of the spinal dorsal horn at the lumbar enlargement, and the COX-2 expression in LPS-treated rats at different time points was measured by immunoblotting technique.  Results   Spinal LTP and COX-2 expression were significantly augmented 4h, but not 12h and 24h after intraperitoneal injection of LPS. NS398, a selective inhibitor of COX-2, reversed the elevated LTP induced by LPS 4h after injection. Elevated COX-2 expression in LPS-treated rats 4h after injection was significantly suppressed by NS398. Conclusion   Activation of COX-2 is involved in changes of LPS-induced spinal LTP.

Key words: Cycclooxygenase-2; Lipopolysaccharides; Long-term potentiation; Spinal cord