Alterations in social behaviour are one of the core deficits in Autism Spectrum Disorder (ASD). Although it is unclear what the fundamental circuits underlie such deficits, numerous authors have proposed the idea that imbalances in the mesocorticolimbic dopaminergic system could be one of the leading causes. In fact, dopaminergic neurons located in the ventral tegmental area (VTA) that innervate the nucleus accumbens (NAcc) and the prefrontal cortex (PFC) are critical for the creation of reward associations, including social reward. We have previously identified functional dopaminergic alterations in the Cntnap2 KO mouse model of ASD. In this work, we perform a molecular characterization of the expression of dopamine-system related molecules. The dopamine system englobes several players, many of which have been associated with ASD. Specifically, the genes encoding dopamine receptors 1, 2 and 3, dopamine transporter or dopa-decarboxylase have been reported as mutated in ASD. Here, we used molecular techniques to measure the expression of the above mentioned genes.Preliminary results show alterations in several dopaminergic markers in different brain regions. These results, complete previous functional results in our laboratory [OP1] and allow us to better understand the mechanisms leading to the deficits of the dopaminergic system associated to social behavior in ASD and inform the development of targeted therapies.