Dopaminergic neurons located in the ventral midbrain are essential for the control of diverse cognitive and motor behaviors and are associated with multiple psychiatric and neurodegenerative disorders, jointly with drug addiction. Three anatomically and functionally distinct subgroups of midbrain dopaminergic neurons have been identified (A8-A10) which give rise to prominent forebrain projections (i.e. mesostriatal, mesocortical and mesolimbic pathways), each one with a different behavioral role. The mesolimbic pathway is involved in drug addiction and there is overwhelming evidence that most of the drugs of abuse, such as: cocaine, amphetamine and even nicotine, increase dopamine transmission in limbic regions of the brain through different mechanisms. The nucleus accumbens (NAc) is the major target of mesolimbic pathway and dopamine release in this area is stimulated after systemic administration of all addictive drugs in mouse. Quantification of dopamine (DA) concentration in in-vivo intracerebral microdialysis study plays a critical role for determination of the effects of drugs in mesolimbic system. Classically, determination of dopamine concentration in microdialysis samples