Fig. 4

In vivo imaging of the acute and chronic inflammatory immune response in the brain of nestin-luc-GFP mice. Single LPS injection showed robust induction of the nestin signal after 24 h (a, b). The signal tends to decrease after 24 h (dotted blue line) (c, d). Repetitive injections of LPS (5 mg/kg) every 3 days produced a second small peak in the nestin signal intensity after 4 days (solid blue line) (e–l). m Quantitative analysis of the nestin signal by in vivo imaging after LPS injection showed a significant increase in signal intensities 24 h after challenge in both experimental paradigm (acute and chronic LPS administration protocols) (LPS vs baseline ***p ≤ 0.0001, n = 8–10/group). The nestin signal gradually decreased to reach baseline level at day 3. Chronic exposure of LPS resulted in fluctuation of the nestin signal expression 2 weeks after of LPS treatment (LPS vs baseline *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001)