Abstract
Exposure of rats to inescapable shock (IS) potentiated the analgesic response to a low dose (1 mg/kg) of morphine 24 hr later. This effect was blocked by naltrexone (10 micrograms), diazepam (5 micrograms), or 8-hydroxy-2-(di-n-propylamine)-tetralin (8-OH-DPAT; 1 microgram) microinjected into the dorsal raphe nucleus (DRN) 15 min before IS. When microinjected into the DRN at the time of tail-flick testing, 8-OH-DPAT also effectively prevented this effect. Further, intra-DRN administration of a beta-carboline mimicked the effects of IS, because rats treated with methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (1 microgram) and simply restrained displayed potentiated morphine analgesia 24 hr later. These data suggest that this phenomenon shares mechanisms in common with other effects of IS at the level of the DRN.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.