Figure 1.

Schematic of the zebra finch song system and auditory pathways to HVC. A, Schematic of a parasagittal section of the zebra finch songbird brain with a subset of the song nuclei illustrated. The thalamic nucleus Uva projects to HVC both directly and indirectly, via NIf. B, Auditory pathways to HVC. Here we identify a pathway from LLV through Uva to HVC (gray). Previous work identified a pathway from the auditory brainstem through the auditory telencephalon to HVC (white). CM, Caudal mesopallium; MLd, dorsal lateral nucleus of the mesencephalon; field L, primary auditory area of the nidopallium; HVC, nucleus HVC of the nidopallium; NCM, caudal medial mesopallium; OV, nucleus ovoidalis; RA, robust nucleus of the arcopallium.