Fig. 1.

Schematic of itch-signaling pathways. 5-HT: 5-hydroxytryptamine (serotonin); ACC: anterior cingulate cortex; BNP: brain natriuretic peptide; CGRP: calcitonin gene related peptide; Dyn: dynorphin; Glu: glutamate; Gly: glycine; GRP: gastrin releasing peptide; IL: interleukin; LTB4: leukotriene B4; Mrgpr: Mas-related G-protein coupled receptor; PAF: platelet activating factor; PAR: protease-activated receptor; SI: primary somatosensory cortex; SP: substance P; Sst: somatostatin; TLR: toll-like receptor; TLSP: thymic stromal lymphopoietin.