Striatal Dopamine at Learned Sequence Boundaries Sustains Birdsong

Phasic striatal dopamine has been implicated in the initiation of well-trained action sequences in reward-guided tasks. Whether such signals also support natural skills learned without explicit cues or immediate rewards remains unknown. Using birdsong as a model of a naturally learned, skilled vocal behavior, we found that dopamine transients accompany the initiation of song sequences. These transients emerged during learning, shifting from later phases of the sequence toward sequence onset as song matured. Temporally targeted optogenetic inhibition of dopamine signaling at sequence onsets disrupted the maintenance of learned song, resulting in the gradual and severe deterioration of adult song. Thus, phasic dopamine signaling at sequence initiation develops during learning of a natural skilled behavior and is required for its long-term maintenance.