Single administration of zinc evokes pharmacological behavioral effects in rodents, while no brain zinc alterations were detected. The aim of the present study was to examine the effect of a single zinc hydroaspartate intraperitoneal (ip) administration on the extracellular (synaptic) zinc concentration in the rat prefrontal cortex. We used anodic stripping voltammetric (ASV) method of zinc determination in microdialysate, which assays the extracellular zinc concentration. We report that acute (65 mg/kg) zinc hydroaspartate administration (ip) increases the extracellular zinc by 48% in the rat prefrontal cortex. These data for the first time demonstrate: 1) utility of ASV zinc detection in brain microdialysates and 2) that single ip zinc administration increases brain (cortical) extracellular zinc pool. The results indicate zinc-induced fast brain penetration and may explain its rapid pharmacological effects.