【Introduction】
Methamphetamine (METH) is addictive drugs widely distributed in the world. Since METH users cannot be recovered from addictive symptoms, a novel medication is required. We have reported that local injection of osteopontin (OPN), an extracellular matrix protein, to the nucleus accumbens (NAc) suppresses behavioral alterations induced by METH in mice. Glatiramer acetate (GA, Copaxone®), a therapeutic reagent for multiple sclerosis, was reported to induce OPN in the brain. Here, we examined the therapeutic effects of GA on METH-induced behavioral alterations in mice. 
【Methods】
C57BL/6J (8-9 weeks, male) received subcutaneous administration of GA (0.1 mg/mouse) and METH (1 mg/kg). After daily administration of GA for 14 days, behavioral analyses were conducted under METH conditioning. The brains were collected for immunohistochemistry (IHC) or flow cytometry (FCM).  
【Results】
Pre-administration of GA to mice suppressed conditioned place preference, not hyperlocomotion, under METH conditioning. IHC and FCM revealed that OPN expression in the brain was upregulated in the microglia and macrophage. 
【Conclusion】
These indicate that GA suppresses METH-preference behavior, possibly mediated by the upregulation of osteopontin. Taken together, GA is indicated to have a therapeutic potential for METH-preference behavior.