Fig. 2

IL-1β immunostaining and cell counts after NA-induced neuroinflammation in TLR2- or TLR4-deficient mice. Histological images from septofimbria (a–c) and hypothalamus (d–f) of WT (a, d), TLR2^-/- (b, e), and TLR4^-/- (c, f) strains 24 h after the injection of NA. Staining was evident in subventricular cells or in cells close to the ventricular surface, and decreased towards deeper regions in the nervous parenchyma. Positive IL-1β label was almost undetectable in samples treated with saline (not shown). Within each image, a magnified detail is shown. IL-1β positive cells were counted in the septofimbria (g) and the hypothalamus (h). In all three strains, NA provoked an increase in IL-1β positive cells, although such increase was slightly lower in TLR2^-/-, and significantly reduced in TLR4^-/-, compared to WT mice. Bars in histograms are the mean + SD of n = 3 saline injected or n = 9–10 NA-injected animals (for each strain). Kruskal-Wallis test was used to compare group means. Letters (a–d) on top of the bars indicate the absence (if same letter) or presence (if different letters) of a significant difference between the compared groups (P < 0.001). LV = lateral ventricle; SF = septofimbria; IIIV = third ventricle