As shown in Figures 5(d) and 5(h), the infection induced a strong increase of IL-1RA mRNA expression in the hippocampal formation and cortex of WT mice (35.8 ± 10- and 38.3 ± 14.7-fold induction for infected WT in the hippocampus and cortex) while the difference between WT and TNFR1−/− in the hippocampus as well as WT and TNFR1−/− and TNFR1-IL-6−/− mice in the cortex reached statistical significance (all p < 0.05; Figures 5(d) and 5(h)). This evidence concerns the gene TNFRSF1A and infection.