Abstract
Groups of rats were given morphine or methadone on a regimen of increasing amounts for 20 days. The animals were then tested using a conditioned avoidance response (CAR) task. Morphine-treated animals tested between 15 min and 3 h after daily injections were clearly superior to saline-injected control animals. Animals tested following self-regulated oral intake of morphine or methadone and animals tested with 1-min, 12-h, or 24-h delays between daily injections and tests performed very much like control rats. A second experiment was performed which indicated that the superior performance of some groups is associated with drug-induced hyperactivity in animals chronically injected with morphine.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
