The mesolimbic dopamine pathway, connecting the VTA to the NAc, plays a key role in the rewarding properties of almost all drugs of abuse. Oxytocin appears to modulate reward signaling in the mesolimbic dopamine system through direct interaction with multiple neurotransmitter systems. Oxytocin projections from the PVN synapse on dopaminergic terminals within the NAc (Knobloch and Grinevich, 2014) and OXTRs are present on VTA dopaminergic projection neurons that target the NAc and medial PFC (Knobloch and Grinevich, 2014, Peris et al., 2017). Central OXT administration has been shown to inhibit drug and alcohol induced increases in dopamine in mesolimbic regions, particularly the NAc (Kovacs et al., 1998, Peters et al., 2017). For instance, intra-NAc infusion of OXT blocked cocaine-induced increases in dopamine utilization (Kovacs et al., 1998) and intracerebroventricular infusions of OXT inhibited methamphetamine-induced dopamine turnover in the NAc (Qi et al., 2008). Similarly, systemically administered OXT decreased methamphetamine-induced activation of the NAc and STN (Carson et al., 2010b). In support of these findings, direct infusion of OXT into the NAc or STN attenuated the development of methamphetamine-induced conditioned place
