For Whom The Bird Sings : Context - Dependent Gene

known about the brain circuits that mediate song acquiMale zebra finches display two song behaviors: disition and production. Referred to collectively as “the rected and undirected singing. The two differ little in song system,” these circuits consist in male zebra the vocalizations produced but greatly in how song is finches of a posterior motor pathway necessary for song delivered. “Directed” song is usually accompanied by production and an anterior pathway necessary for song a courtship dance and is addressed almost exclusively acquisition. Both pathways originate in the high vocal to females. “Undirected” song is not accompanied by center (HVC) of the neostriatum. In the posterior pathway the dance and is produced when the male is in the (Figure 1B, black arrows), neurons of one cell type in presence of other males, alone, or outside a nest occuHVC project to the robust nucleus of the archistriatum pied by its mate. Here, we show that the anterior fore(RA); RA in turn projects to the dorsomedial (DM) nucleus brain vocal pathway contains medial and lateral “cortiof the midbrain and to motoneurons (nXIIts) that innercal–basal ganglia” subdivisions that have differential vate muscles of the trachea and syrinx. In the anterior ZENK gene activation depending on whether the bird pathway (Figure 1B, gray arrows), neurons of a different sings female-directed or undirected song. Differences cell type in HVC project to Area X of the paleostriatum; also occur in the vocal output nucleus, RA. Thus, alArea X in turn projects to the medial nucleus of the though these two vocal behaviors are very similar, dorsolateral thalamus (DLM); DLM projects to the lateral their brain activation patterns are dramatically difmagnocellular nucleus of the anterior neostriatum (lMAN); ferent. and lMAN projects both to RA and back to Area X (see