Pharmacological manipulations of dopamine and opioids have differential effects on sexually motivated song in male European starlings.

Vocal communication is common among social vertebrates, though little is known about the neural mechanisms regulating the motivation to communicate. This study examined a possible role for dopamine and opioids in sexually motivated song in male European starlings. The dopamine reuptake inhibitor GBR-12909 increased singing behavior, whereas the D1 dopamine receptor antagonist SCH-23390 decreased song, suggesting a role for dopamine in the motivation to sing. In contrast, the opioid agonist fentanyl decreased song, and the antagonist naloxone has previously been shown to increase song, findings consistent with a role for opioids in reward associated with song production. These results suggest that dopamine and opioids play opposing roles in the regulation of the motivation to communicate.