Deep brain stimulation in the ventral tegmental area (VTA) has shown promise in modulating reward and learning. However, its underlying molecular mechanisms are still largely unexplored. In this study, fMRI and PET together with selective pharmacological blocking was used to distinguish dopamine receptor subtype-specific mechanisms of VTA stimulation in a non-human primate model with a chronically implanted stimulation electrode. Our results show that the main dopaminergic contribution to fMRI signal is likely driven by D1 receptor signaling, with a smaller D2 receptor contribution. Overall, this is a novel finding distinguishing dopaminergic receptor subtypes involved in VTA stimulation.