Fig. 3

LL rats produced more TNF-α and showed increased sickness behavior in response to LPS. (a) TNF-α plasma levels after the administration of 2μg/kg of LPS. The repeated-measures two-way ANOVA indicated a significant effect due to the interaction condition versus time, p = 0.0065. The Bonferroni test **p < 0.01 indicated statistical difference from LD. (b) Thermoregulatory response to LPS. The arrow represents LPS administration at ZT2 for both groups. The mean day-night core body temperature (Tb) is shown in the box, for LD (grey bars) and LL (white bars), stripped bars in each group represent the night. The repeated-measures two-way ANOVA indicated a significant effect due to light condition p = 0.0107; and time p = 0.0011. The Bonferroni test p < 0.05 indicated statistical difference from LD and # between LL. (c) Thermoregulatory response 24 h post LPS. The mean day-night core body temperature (Tb) is shown in the box. The subjetive day-night phases for LL rats were selected based on the 12 h day and 12 h night of LD animals. The repeated-measures two-way ANOVA indicated effects due to the interaction condition versus time, p = 0.0011; the Bonferroni test indicated *p < 0.05 statistical difference from LD and & between LD. (d) Food intake, (e) Water intake and (f) Weight gain during the day of LPS administration, 24 and 48 h post LPS in LD and LL rats. Values are expressed as a percentage of the baseline value established prior to LPS administration. For d, the repeated-measures two-way ANOVA indicated effects due to lighting condition p = 0.0107 and time p = 0.0011. Data are the mean ± SEM (n = 6/group). *p < 0.05 indicates statistical difference from LD; with Bonferroni test