Kerman University of Medical Sciences

Document Type: Original Article(s)

Authors

1 MSc Student, Department of Physiology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran

2 Assistant Professor, Department of Physiology, School of Medicine, Bojnord University of Medical Sciences, Bojnord, Iran

3 Professor, Neuroscience Research Center, Institute of Neuropharmacology, Department of Physiology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran

4 Researcher, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran

5 Professor, Neuroscience Research Center AND Department of Physiology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran

6 General Practitioner, Welfare Organization, Kerman, Iran

Abstract

Background: Opioids have been shown to affect learning and memory processes. Different protocols of morphine withdrawal can substantially vary in their success to prevent opioid induced impairments of cognitive performance. In the present study, we report the effects of single and repetitive ultra-rapid detoxification (URD) on spatial learning and memory in morphine addicted rats. Methods: Morphine (10 mg/kg) was intraperitoneally (IP) injected in male rats once a day over one week and after which they were detoxified with naloxone administration under anesthesia. For the repetitive procedure, a second one week morphine treatment with a second subsequent detoxification was performed. Control groups received an equivalent volume of saline injections. Spatial learning and memory was evaluated using the Morris water maze (MWM) task. Findings: Both protocols of morphine administration resulted in a severe spatial memory impairment that could be significantly prevented by both single and repetitive URD. However, memory abilities in animals treated with repetitive URD were still significantly lower than in animals of the corresponding control group. Alterations in motor activity or sensory-motor coordination between morphine treated and control animals could be ruled out by comparing swimming speed and visible platform performances that were not different between groups. Thus, URD and, specifically single URD, can prevent the spatial memory impairments in addicted rats. Conclusion: As opioid addiction is an extending and serious concern in many societies, these findings may have clinical values and therapeutic implications for patients who experience multiple opioid relapses.

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