Substance use disorders (SUD) has a significant impact on human wellbeing and carries a high economic cost in the modern world. Astrocytes are known to participate in all major aspects of brain functions by regulating extracellular levels of neuroactive molecules. Notably, astrocytes were previously shown to critically adjust levels of dopamine in the prefrontal cortex (PFC) through astroglial vesicular monoamine transporter 2 (aVMAT2). Our recent data also indicate aVMAT2 expression in the nucleus accumbens (NAcc)., As SUD engages common neural pathways involved in natural reward processing in PFC and NAcc through dopaminergic signaling, we here investigate whether and how aVMAT2 contributes to dopamine modulations in acute action of drugs and in the self-administration paradigm of cocaine or natural rewards. To this end, we measured reward- or drug-seeking behaviors in controls and in mice lacking aVMAT2 (aVMAT2cKO line). We found that aVMAT2KO mice display a reduced travelled distance and locomotor sensitization in response to consecutive cocaine injections. In self-administration paradigm, we observed a marked motivational deficit for natural reward (sucrose) in aVMAT2cKO mice. Both of these effects may rely on the impaired tonic level of dopamine due to the knock-down of aVMAT2 pathway. This hypothesis is supported by our current neuroimaging data of extracellular dopamine release with the fluorescent sensors GRABDA. These findings establish an initial framework for understanding precise dynamics of extracellular dopamine in SUD and natural rewards as well as providing potential target to correct impaired dopamine balance.