Pain
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It has been suggested that spinal cord long-term potentiation (LTP) may contribute to hypersensitivity and hyperalgesia. We have investigated if noxious stimulus-induced spinal cord LTP might have a long lasting effect on supraspinal neuronal activity. First, we verified that spinal LTP was induced by electrical high frequency stimuli (HFS) conditioning applied to the sciatic nerve. ⋯ The study demonstrates that PET may be used as an in vivo method to study regional brain metabolic activity between different conditions. It is concluded that noxious sciatic stimuli which induce spinal cord LTP also affect supraspinal metabolic activity. We suggest that these changes might illustrate a supraspinal maladaptive dysfunction involved in pain hypersensitivity and hyperalgesia.
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Resveratrol is a natural polyphenol that protects from cancer and cardiovascular diseases. Resveratrol is able to induce apoptotic cell death and it inhibits the cyclooxygenase (COX) cascade. We measured the antinociceptive effect of resveratrol on carrageenan-induced hyperalgesia, prostaglandin-E2 (PGE2) concentration in CSF and COX-1/COX-2 gene expression in the spinal cord and dorsal root ganglion (DRG) in rats. ⋯ In conclusion, the antinociceptive effect exhibited by resveratrol was related to the prevention of COX-2 mRNA increase induced by carrageenan. Resveratrol also prevented the bilateralisation of COX-2 expression. The later effect, together with the prolonged analgesia induced by a single injection, may be of great benefit for preventing chronic pain states often seen after inflammatory insults.