title: Neuropeptide S reduces propofol- or ketamine-induced slow wave states through activation of cognate receptors in the rat.
abstract: Intracerebroventricular injection of NPS reduces the duration of the ketamine- or thiopental-induced loss of the righting reflex in rats. But the specific EEG activities are unknown. We therefore sought to examine the effects of the NPS-NPSR system on anesthetic-induced characteristics of EEG power spectra and sleep-wake profiles. NPS alone or together with an NPSR antagonist was injected intracerebroventricularly, whereas the propofol (50mg/kg) or ketamine (100mg/kg) was administrated intraperitoneally. NPS (1 or 2nmol) significantly reduced the amount of propofol-induced EEG delta activity and slow wave states (SWS). NPS (1 or 5nmol) significantly reduced the amount of ketamine-induced SWS and EEG delta activity. Cortical EEG power spectral analysis showed that, in saline-pretreated rats, propofol induced a marked increase in delta (0.5-4Hz) activity, decrease in theta (4.5-8.5Hz) activity, and decrease in high frequency activity (14.5-60Hz), while, in rats pretreated with 1nmol of NPS, the duration of delta activity was reduced, while its spectral pattern was not changed. Whereas injection of ketamine into saline-pretreated rats induced a marked increase in delta (0.5-4Hz) activity, a moderate increase in theta (4.5-8.5Hz) activity, and a marked decrease in high frequency (14.5-60Hz) activity. However, delta activity was reduced while theta activity increased under pretreatment with 1nmol of NPS. The inhibitory effect of NPS on anesthetic-induced SWS was characterized by a reduced SWS episode duration with no significant change in either episode number or latency to SWS. [D-Val5]NPS, an NPSR antagonist (20nmol), significantly attenuated the arousal-promoting effect of 1nmol of NPS, but had no effect on SWS when injected alone. We speculate that NPS significantly reduces anesthetic-induced SWS and EEG slow activity by selective activation of the NPSR, which, in turn, would trigger subsequent arousal pathways.
authors.affiliation: Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, China; Department of Human Anatomy, Hunan Normal University, Changsha, China.
authors.forename: Xiang-Pan
authors.initials: XP
authors.lastname: Kong
authors.affiliation: Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, China.
authors.forename: Can
authors.initials: C
authors.lastname: Wang
authors.affiliation: Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, China.
authors.forename: Jun-Fan
authors.initials: JF
authors.lastname: Xie
authors.affiliation: Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, China.
authors.forename: Li-Rong
authors.initials: LR
authors.lastname: Dai
authors.affiliation: Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, China. Electronic address: shaoyf@lzu.edu.cn.
authors.forename: Yu-Feng
authors.initials: YF
authors.lastname: Shao
authors.affiliation: Integrative Physiology of the Brain Arousal Systems, Lyon Neuroscience Research Center, INSERM U1028-CNRS UMR 5292, University Claude Bernard Lyon 1, Lyon, France. Electronic address: lin@univ-lyon1.fr.
authors.forename: Jian-Sheng
authors.initials: JS
authors.lastname: Lin
authors.affiliation: Departments of Neuroscience, Anatomy, Histology, and Embryology, Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Lanzhou University, Lanzhou, China. Electronic address: houyiping@lzu.edu.cn.
authors.forename: Yi-Ping
authors.initials: YP
authors.lastname: Hou
mesh_terms: D000818:Animals; D003700:Delta Rhythm / Q000187:drug effects*; D004569:Electroencephalography; D007649:Ketamine / Q000494:pharmacology*; D008297:Male; D009479:Neuropeptides / Q000494:pharmacology*; D015742:Propofol / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018013:Receptors, Neuropeptide / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D009479:Neuropeptides; D018013:Receptors, Neuropeptide; C568280:neuropeptide S receptor, rat; C534458:neuropeptide S, rat; D007649:Ketamine; D015742:Propofol