TNF-α/TNFR1 Signaling is Required for the Full Expression of Acute and Chronic Itch in Mice via Peripheral and Central Mechanisms

TNFR1, but not TNFR2, is required for both histaminergic and non-histaminergic itch in mice. A Time course of acute histaminergic itch induced by compound 48/80 (48/80) in wild-type (WT), TNFR1-KO, TNFR2-KO, and TNFR1/R2 DKO mice. B Total scratching bouts within 30 min induced by 48/80 in all four groups of mice. C Time course of acute non-histaminergic itch induced by chloroquine (CQ) in WT, TNFR1-KO, TNFR2-KO, and TNFR1/R2 DKO mice. D Total scratching bouts within 30 min induced by CQ in all four groups of mice. Data are presented as mean ± SEM ( P < 0.05 vs WT group one-way ANOVA followed by Bonferroni post hoc test; n = 5–7 mice per group)