Objective The study is to observe the effect of nitric oxide（NO） donor and scavenger to the hypoglossal motor nucleus（HMN） activity and explore the underlying mechanism. Methods Male adult anesthetized Wistar rats were anesthetized. The activity of genioglossus（GG）, diaphragma, blood pressure（BP） and respiratory rate（RR）were recorded when constant microdialysis perfusion of artificial cerebrospinal fluid（ACSF） to HMN as control, followed with diethylamine NONOate sodium salt hydrate（DEA）, a NO donor, and 2-（4-carboxyphenyl）-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt（carboxy-PTIO）, a NO scavenger. Results Compared with ACSF, application of DEA and carboxy-PTIO at HMN increased and decreased the GG activity respectively and significantly（P
