Cerebral modulation of IL-1β and NF-κB by NO donors. GNT and SNP increased the expression of IL-1β within PAG (a) and thalamus (b) with a peak at 4 h after administration. LPS was used as positive control. NO donors produced a cerebral activation of the NF-κB pathway as indicated by the reduction of Iκ-Bα levels in the PAG (c) and thalamus (d). NO donors increased c-Fos protein levels in the PAG (c) and thalamus (d) with a similar time course to the nociceptive hypersensitivity. ,, compared with vehicle-treated control group (c).