Ventral mesencephalic delta opioid receptors are involved in modulation of basal mesolimbic dopamine neurotransmission: an anatomical localization study.

Microdialysis was used to examine the anatomical localization of mesencephalic delta opioid receptors that participate in modulation of mesolimbic dopamine (DA) neurotransmission. Independent groups of rats were injected with DPDPE into the ventral tegmental area (VTA) or interpeduncular nucleus (IPN). Extracellular nucleus accumbens DA and DOPAC concentrations were elevated after DPDPE injections into either site, but injections into the VTA were effective at lower doses than were injections into the IPN. Thus, it appears that the DA-modulating actions of DPDPE are mediated in the VTA rather than the IPN.