001) and 13 h (p < 0.05)

and significantly different to ME7 + saline animals at 9 and 13 h (p < 0.001). Conversely ME7 + saline were not different to NBH + saline at any time point (p > 0.05). Similar early and exaggerated hypothermic responses were seen after poly I:C challenge to ME7 animals at 16 and 18 weeks (data not shown). As shown in Fig. 3 poly I:C induced differential hippocampal responses in NBH and ME7 animals 18 weeks post-inoculation. TNF-α mRNA was markedly induced in ME7 animals per se ( Fig. 3a). One-way ANOVA (F = 51.85, df 5, 26, p = 0.0001) with selected Bonferroni post hoc tests revealed that ME7 + saline was significantly different to NBH + saline. Systemic challenge with poly I:C induces opposite effects on TNF-α in NBH and ME7 animals. Levels in ME7 + poly I:C animals were NVP-BKM120 in vitro actually depressed at 4 h with respect to ME7 animals and statistically significantly lower at 6 h (p < 0.001 by one-way ANOVA with Bonferroni post hoc test). Poly I:C induced very marked increases by 4 h in IL-6 in the hippocampus of both NBH and ME7 animals (Fig. 3c). The increase learn more was, however, more marked in ME7 + poly I:C animals. A significant one-way ANOVA (F = 65.01, df 5, 26, p < 0.0001) with selected Bonferroni pairwise tests revealed no difference between IL-6 levels in NBH + saline and ME7 + saline animals (p > 0.05), but showed that ME7 + poly

I:C at 4 h was significantly different to NBH + poly I:C (p < 0.001) and these levels decreased somewhat by 6 h. IL-1β mRNA was clearly induced in the hippocampus of ME7 animals at 4 h post-poly I:C and returned to near baseline levels by 6 h in normal animals. The poly-I:C-induced PIK3C2G increase was markedly higher in ME7 animals (Fig. 3b). One-way ANOVA (F = 24.54, df 5, 26, p < 0.0001) followed by selected Bonferroni post hoc comparisons showed that ME7 + saline was significantly higher than NBH + saline (p < 0.05). The IL-1β increase post-poly I:C was more marked in ME7 than in NBH (p < 0.001). IFNβ, which is IRF3-dependent, was induced more markedly in the hippocampus

of ME7 animals treated with poly I:C (Fig. 3d) and appeared to peak at 4 h. A significant one-way ANOVA (F = 18.45, df 5, 25; p < 0.0001) followed by Bonferroni post hoc tests revealed that ME7 + poly I:C was significantly higher than NBH + poly I:C at their peak values (p < 0.01), but ME7 + saline and NBH + saline were not significantly different (p > 0.05). PTX3, an NFκB-dependent gene with no reported regulation by IRF3, showed an exaggerated induction in the hippocampus of ME7 + poly I:C compared to NBH + poly I:C. Levels of this transcript were still rising at 6 h (Fig. 3e), distinct from the NFκB-dependent, primary response genes IL-1β, TNFα and IL-6 (Fig. 2a and b) and consistent with secondary induction by IL-1β. Selected Bonferroni post hoc comparisons after a significant one-way ANOVA (F = 9.27, df 5, 25, p < 0.