Ding-Dong, the Itch Is Dead

Gastrin-releasing peptide receptor (GRPR) is a G-protein–coupled receptor that has been implicated in a variety of physiologic processes and behaviors, including food intake and fear memory. Prompted by previous findings that intracerebral administration of bombesin (an animal homologue of GRP) elicited grooming behavior in rodents, investigators tested the hypothesis that GRPR is, in fact, the itch receptor.

The investigators first found that GRP is expressed in a subset of small and medium-sized dorsal-root ganglion, unmyelinated neurons. Prior findings have suggested an itch-dedicated pathway in the peripheral and central nervous system that involves a group of itch-specific, unmyelinated C-fibers and spinothalamic lamina I neurons in the…