Young birds learn to sing during a critical period of development. Although the song system circuits have been identified, the molecular systems responsible for song template memorization have remained unknown. On page 579, London and Clayton reveal a critical role for the ERK signaling pathway in auditory cortex during normal song learning.

Male zebra finches copy the songs of older tutors when learning to sing. Auditory memories are initially formed, and through sensorimotor correction, the young bird eventually adopts a song that mimics the template derived from the tutor. In the new paper, the authors pharmacologically disrupted ERK signaling by injecting inhibitors into the auditory lobule during song learning exposure, presumably as the young bird was creating its template. Although the injection site was located outside the song system, these animals produced poor copies of the tutor song as compared to controls. Therefore, a brain region distinct from the areas controlling song output is integral to song learning and development.

There are efferent connections between the disrupted auditory area and the song system, suggesting that error feedback mechanisms between sensory and motor areas may be deficient when ERK signaling is disrupted. These results emphasize the importance of looking beyond the 'simple' circuits involved in species-specific actions to determine how multiple interacting systems in the brain shape behavior.