olanzapine antagonizes the acquisition and expression of morphine-induced conditioned place preference in male and female mice

introduction: several investigations have indicated that dopamine d receptors could influence morphine 2 eward. the influence of olanzapine (a d dopamine receptor antagonist) on the morphine-induced conditioned 2 lace preference (cpp) in male and female mice was investigated in the present study. methods: the effects of olanzapine on the acquisition and expression of morphine cpp in male and female -mri mice (w: 20-25 g) were investigated in the present study. resultd: subcutaneous (s.c.) injection of morphine (1-10 mg/kg, three drug sessions) induced place preference oth in male and female mice. intraperitoneal (i.p.) administration of olanzapine (0.5-5 mg/kg) induced place version (cpa) in female mice but not in male mice. administration of olanzapine (1, 2.5, 5 mg/kg, i.p.) reduced oth the acquisition and expression of morphine-induced cpp in male and female mice. however, olanzapine (5 g/kg, i.p.) caused more than 80% mortality in female but not male mice. the effects of olanzapine were reversed y l-arginine (20 mg/kg, i.p.) pre-administration. conlusion: we conclude that olanzapine reduced morphine effects via different mechanism/s.