Distinct roles of NMB and GRP in itch transmission

Li Wan, Hua Jin, Xian-Yu Liu, Joseph Jeffry, Devin M. Barry, Kai-Feng Shen, Jia-Hang Peng, Xue-Ting Liu, Jin-Hua Jin, Yu Sun, Ray Kim, Qing-Tao Meng, Ping Mo, Jun Yin, Ailin Tao, Rita Bardoni & Zhou-Feng Chen: Scientific Reports, Volume 7, Issue 1, 1 December 2017, Article number 15466 Read More

Abstract

A key question in our understanding of itch coding mechanisms is whether itch is relayed by dedicated molecular and neuronal pathways. Previous studies suggested that gastrin-releasing peptide (GRP) is an itch-specific neurotransmitter. Neuromedin B (NMB) is a mammalian member of the bombesin family of peptides closely related to GRP, but its role in itch is unclear. Here, we show that itch deficits in mice lacking NMB or GRP are non-redundant and Nmb/Grp double KO (DKO) mice displayed additive deficits. Furthermore, both Nmb/Grp and Nmbr/Grpr DKO mice responded normally to a wide array of noxious stimuli. Ablation of NMBR neurons partially attenuated peripherally induced itch without compromising nociceptive processing. Importantly, electrophysiological studies suggested that GRPR neurons receive glutamatergic input from NMBR neurons. Thus, we propose that NMB and GRP may transmit discrete itch information and NMBR neurons are an integral part of neural circuits for itch in the spinal cord. © 2017 The Author(s).

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Posted on November 18, 2017
Posted in: HPAN, Neurodegeneration, Neurogenetics & Transcriptomics, Publications Authors: