期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：52
页码：27011-27017
DOI：10.1073/pnas.1905658116
出版社：The National Academy of Sciences of the United States of America
摘要：Spinal gastrin-releasing peptide receptor-expressing (GRPR + ) neurons play an essential role in itch signal processing. However, the circuit mechanisms underlying the modulation of spinal GRPR + neurons by direct local and long-range inhibitory inputs remain elusive. Using viral tracing and electrophysiological approaches, we dissected the neural circuits underlying the inhibitory control of spinal GRPR + neurons. We found that spinal galanin + GABAergic neurons form inhibitory synapses with GRPR + neurons in the spinal cord and play an important role in gating the GRPR + neuron-dependent itch signaling pathway. Spinal GRPR + neurons also receive inhibitory inputs from local neurons expressing neuronal nitric oxide synthase (nNOS). Moreover, spinal GRPR + neurons are gated by strong inhibitory inputs from the rostral ventromedial medulla. Thus, both local and long-range inhibitory inputs could play important roles in gating itch processing in the spinal cord by directly modulating the activity of spinal GRPR + neurons.
