tokens: OBJECTIVES : Given its preclinical success for treating substance abuse and the increased risk of visual field defects ( VFD ) associated with cumulative lifetime exposure , we explored the effects of sub - chronic low dose GVG on cocaine - induced increases in nucleus accumbens ( NAcc ) dopamine ( DA ). METHODS : Using in vivo microdialysis , we compared acute exposure ( 450 mg / kg ) to an identical sub - chronic exposure ( 150 mg / kg per day for 3 days ), followed by 1 - or 3 - day washout .