Priming dose of morphine/methamphetamine combination induced stereotyped behavior in morphine/methamphetamine-dependent mice

• Main Authors: Suhaimi, Maryam Saadah, Ridzwan, Irna Elina, Muhamad, Abdul Halim, Mohd Ghazali, Masitah, Kasmuri, Abdul Razak, Mohd Nazar, Nor Ilyani, Hashim, Ridzwan, Syd Mohmad Faudzi, Syed Mohd Syahmi
• Format: Conference or Workshop Item
• Language: English
• Published: 2015
• Subjects: RS Pharmacy and materia medica
• Online Access: http://irep.iium.edu.my/44310/1/ICBHSR_2015.pdf; http://irep.iium.edu.my/44310/

Concurrent use of methamphetamine and morphine could give a synergistic effect, where it produce greater rewarding effects, and antagonize the side effects of each other, causing it to have a greater potential to be abused. This poly-drug abuse may lead to behavioral sensitization shown by stereotype behavior. The aim of this study is to compare the behavioral effects of priming dose in reinstatement model of morphine- and morphine/methamphetamine-dependent mice. Through conditioned place preference (CPP) test, dependence was successfully established by using 7.5 mg/kg morphine and/or 1 mglkg methamphetamine and then, extinction was achieved by retesting style. The mice were later challenged with priming dose of 2.5 mg/kg morphine and/or 'l mg/kg methamphetamine. Significant preference towards the drug-paired compartment were shown in both morphine- and morphine/methamphetamine-dependent mice (P<0.05 n=12). However, stereotyped behavior was developed only in morphinelmethamphetamine-dependent mice (45-60 mins). This result indicates that concurrent use of morphine and methamphetamine can induce behavioral sensitization in reinstatement modelof morphine/methamphetamine-dependence mice. This finding suggests that stereotype behavior can be one of the parameter to examine drug addiction and craving in animal model and to extend it to human. Thus, this study may lead to potential treatment for poly-drug abuse and the treatment should be designed to inhibit both reinstatement and behavioral sensitization effect of the drug^ Further study on relapse and behavioral sensitization in methamphetamine-dependent mice should be carried out to ascertain any cross-sensitization between morphine and methamphetamine.