Chronic morphine treatments alter IL-1β expression in different brain regions of mice. Values represent mean ± SEM (n = 8 per group)
Panel A: IL-1β expression in hippocampus significantly increased for wild-type C57BL/6 (p < 0.001) but not for CBA (p > 0.05) and Balb/c (p > 0.05) strains in morphine-treated group, and did not change for TLR4 KO and MyD88 KO strains between treatments (p > 0.05).
Panels B and C: IL-1β expression in brain stem (B) and midbrain plus diencephalon regions (C) - no statistically significant change in IL-1β expression between treatments for all strains (p > 0.05).
Panel D: IL-1β expression in medial prefrontal cortex (mPFC) - significantly decreased for wild-type Balb/c (p < 0.05), but not for CBA (p > 0.05), C57BL/6 (p > 0.05) and MyD88 KO (p > 0.05) mice in morphine treated group and no change for TLR4 KO mice (p > 0.05) between treatments.
Panel E: IL-1β expression in cortex - no statistically significant change of IL-1β expression between treatments for all strains (p > 0.05).
*: p < 0.05, ***: p < 0.001