Potentiation of dopamine D1-like receptor signaling by concomitant activation of δ- and μ-opioid receptors in mouse medial prefrontal cortex

► The study investigates the interaction between opioid and DA D1 receptors in mPFC. ► δ- and μ-opioid receptors potentiate DA D1-stimulated cyclic AMP formation. ► D1 stimulation of GluR1, NR1 and CREB phosphorylation is enhanced by leu-enkephalin. ► Cultured cortical cells show co-expression of D1, δ- and μ- receptor immunoreactivity.