Figure 2.

(Left) IL-1β secretion in ovine primary astrocyte cultures in response to 6 h LPS exposure without or with pre-incubation with α7nAChR antagonist (B100) or agonist (A10) for 1 h. Single hit, in vitro only LPS exposure; second hit, in vivo systemic and subsequent in vitro LPS exposure 4 to 5 weeks later. Y axis shows fold changes in IL-1β in relation to the levels of sham treatment (LPS). Generalized estimating equations (GEE) modeling results are presented in text and no significance marks are provided in the figure. For both box plots, an asterisk represents an extreme outlier (a value more than 3 times the interquartile range from a quartile). A circle marks outlier with values between 1.5 and 3 box lengths from the upper or lower edge of the box. Briefly, we found significant main term effects (p = 0.019) “treatment” (LPS and α7nAChR drug) as well as main term “hit” (p = 0.010), i.e., the contribution of in vivo LPS exposure, the second hit effect on the IL-1β secretion profile. Results are provided as median {25–75} percentiles. (Right) Identical experimental results from microglia studies are presented for comparison. The main terms “hit” and “treatment” were not significant (p = 0.716 and p = 0.666, respectively), but their interaction was significant (p = 0.026, cf. Figure 1 in (3) where the original results have been published.