Figure 1.

Neonatal (P3) E. coli infection caused transient brain inflammation and microglial activation. Neonatal BALB/c mice (P3) were injected subcutaneously with either sterile saline (CON) or E. coli (ELI). Brains were collected from male and female mice 24, 48, or 72 h later and mRNA levels of (A) CD11b, (B) IL-1β, (C) IL-1R1 and (D) TNFα were determined (n = 7). In a related study, male and female mice were infected as above. The brain was collected 24 h later and Iba-1 protein expression was determined. E, Representative images of Iba-1 labeling in the CX of both CON and ELI mice are shown (scale bar, 100 μm). Insets show enlarged image of microglia (scale bar, 50 μm). F, Digital image analysis of Iba-1 proportional area in the cortex (n = 4). Bars represent the mean ± SEM. Means with asterisk are significantly different from controls (p < 0.05). Means with plus sign denote a tendency (p ≤ 0.1).