Effects of Desipramine on Morphine‑Induced Conditioned Place Preference in Mice

In this study, we aimed to investigate the effects of Desipramine on morphine dependence and inhibition of reinstatement using the Conditioned Place Preferences (CPP) test in mice.

In this study, two protocols were used to evaluate morphine dependency and reinstatement: In one of these protocols, 40 mice were equally assigned into 8 groups of normal saline, normal saline/morphine, three groups of morphine/DES (12.5, 25 and 50 mg/kg/day with morphine 40 mg/kg) and three groups of DES (12.5, 25 and 50 mg/kg). The time spent in the black and white compartments was calculated on day 3 and 8. In the next step, 20 mice were equally divided into 4 groups: one received normal saline/morphine and the other three groups received morphine/DES at 12.5, 25 and 50 mg/kg/d. In the other protocol, animals underwent a period of abstinence, then, they received 10 mg/kg morphine as a reminder dose in order to elucidate morphine reinforcement. Finally, the time spent in white and black box were calculated.

The results confirmed animals addiction following morphine administration (40 mg/kg for four days), in CPP apparatus. In the first protocol, DES at 25 and 50 mg/kg significantly reduced morphine tendency. In the second protocol, DES at 25 and 50 mg/kg significantly reduced morphine reinstatement. But, DES 12.5 mg/kg did not commit morphine reinstatement.

The results confirmed that DES 25 and 50 mg/kg prohibited morphine tendency and reinstatement.