Heightened neonatal cytokine responses in the CNS following TLR4 and TLR9 stimulation. Neonatal (gray bars) and weanling (open bars) mice were inoculated intracerebrally (ic) with LPS or CpG-ODN at the concentrations described in the Methods section. Control groups were either not inoculated (none) or inoculated ic with PBS. At 12 hpi, brain tissue was removed and processed for protein analysis. Cytokine protein levels in brain homogenates from neonatal and weanling mice were measured using a Multiplex bead assay. n = 10 to 12 for neonates and 5 to 6 for weanling mice. Data are presented as mean ± SEM. Statistical analysis was completed by two-way analysis of variance with Sidak’s multiple comparisons test. Significant age-specific differences are as indicated: *P < 0.05, **P < 0.01, ***P < 0.001.