Fig. 1.

(A) Intraperitoneal thermometers (dataloggers) were implanted in 8 male and 8 female TLR4^fl/fl mice on C57BL/6 background. After 1 week, male (n = 4) and female (n = 4) mice were subjected to subarachnoid injection of 60 μl of whole blood from CD45.1⁺ mice (C57BL/6 background); the remaining 8 mice were subjected to subarachnoid injection of 60 μl of normal saline. Post-SAH surgery (36 h), temperatures were recorded from the two groups and are shown for every 8 h, with mean and standard error of the mean. The mice subjected to SAH had significantly higher temperatures at all time points by two-way ANOVA (p < 0.03; n = 16). (B) Fever burden was calculated by subtracting 36.5 °C from each time point, 36 h after SAH surgery, and summing the values over 3.125 days, or 300 measurements at 15-min intervals. Intracerebroventricular injection of 5 μg of lipopolysaccharide was performed as a control for TLR4-dependent fever in male (n = 3) and female (n = 3) TLR4^fl/fl mice. Statistical significance was determined by Student’s t test and showed no difference