Anteromedial thalamic nucleus to anterior cingulate cortex inputs modulate histaminergic itch sensation

• Published in: Neuropharmacology 2020-05, Vol.168, p.108028-108028, Article 108028
• Main Authors: Deng, Ying-Zhi, Lu, Yu-Chen, Wu, Wei-Wei, Cheng, Li, Zan, Gui-Ying, Chai, Jing-Rui, Wang, Yu-Jun, Chen, Zhong, Liu, Jing-Gen
• Format: Article
• Language: English
• Subjects: Anterior cingulate cortex; Anteromedial thalamic nucleus; Histamine; Itch
• ISSN: 0028-3908; 1873-7064
• DOI: 10.1016/j.neuropharm.2020.108028

Itch is an unpleasant feeling that triggers scratching behavior. Much progress has been made in identifying the mechanism of itch at the peripheral and spinal levels, however, itch circuits in the brain remain largely unexplored. We previously found that anterior cingulate cortex (ACC) to dorsal medial striatum (DMS) inputs modulated histamine-induced itch sensation, but how itch information was transmitted to ACC remained unclear. Here, we demonstrated that the anteromedial thalamic nucleus (AM) was activated during histaminergic itch, and there existed reciprocal neuronal projections between AM and ACC. Disconnection between AM and ACC resulted in a significant reduction of histaminergic, but not nonhistaminergic, itch-related scratching behavior. Optogenetic activation of AM-ACC, but not ACC-AM, projections evoked histaminergic itch sensation. Thus, our studies firstly reveal that AM is critical for histaminergic itch sensation and AM-ACC projections modulate histaminergic itch-induced scratching behavior. •Anteromedial thalamic nucleus (AM) was activated during histaminergic itch.•Photoactivation of AM induced spontaneous scratching behavior.•There existed reciprocal neuronal projections between AM and ACC in the brain.•Disconnection of AM and ACC circuit attenuated histaminergic-induced itch.•Photoactivation of AM-ACC inputs evoked histaminergic itch sensation.