Fig. 1 |. Meningeal lymphatic ablation exacerbates sickness behavior.

a, Experimental scheme involving 2-month-old male mice injected with Visudyne intra-cisterna magna (i.c.m.) and photoactivated for ablation or without photoactivation for sham. Seven days later, IL-1β-induced sickness behavior was quantified by repeated 10-min open field test at 1, 2, 3 and 6 h following 1 μg IL-1β or saline i.p. injection. b, Representative heatmaps depict mouse position over 10 min, 2 h following saline or IL-1β injection. c, Exploratory activity of lymphatic ablated and sham mice following saline or IL-1β injection (n = 8 sham with saline, n = 7 ablation with saline, n = 8 sham with IL-1β, n = 6 ablation with IL-1β-injected male mice). d,e, Food consumption of mice with different treatments, 3 and 6 h after IL-1β i.p. injection (n = 10 sham, n = 9 ablation). f–h, Sucrose preference as compared with baseline and IL-1β-treated groups for sham and ablation measured for 12 h (n = 8 sham, n = 10 ablation-treated mice). Base., baseline. g, No difference in total fluid intake was seen between sham and ablation groups in either the baseline or IL-1β-treated groups. h, Sucrose preference as compared with baseline for each group. i, IL-1β detected by enzyme-linked immunosorbent assay (ELISA) of plasma from IL-1β KO and WT mice 2 h following IL-1β or saline i.p. injection (n = 3 samples consisting of plasma from two pooled male mice each). j, Exploratory activity of IL-1β KO mice following IL-1β or saline injection (n = 8 male mice per group). c, Three-way analysis of variance (ANOVA). e, Two-tailed unpaired Mann–Whitney test. g, h, Two-way ANOVA with Tukey’s post hoc test. i, Two-way ANOVA with Tukey’s post hoc test. j, Two-way ANOVA with Sidak’s post hoc test. Data in panels c, e, g, i, and j are presented as mean ± s.e.m. The experiments in panels c, i and j were repeated in duplicates, and one experimental set of data is presented. Data in panels e, g and h resulted from a single experiment.