Neural correlates of song complexity in Bengalese finch high vocal center.

Auditory neurons in the songbird forebrain nucleus high vocal center HVC) show high selectivity to the temporal structure of bird's own song but the relationship between the degree of song complexity and neural selectivity is not known. We investigated the song temporal selectivity of HVC neurons by multi-unit recordings in seven male Bengalese finches with different song complexity. Results showed that HVC multi-units of the individuals with more complex songs responded strongly to each of the self-generated song elements but were relatively insensitive to the element order, while those with stereotyped songs responded only to the song elements ordered exactly as in the self-produced songs. Data suggest that the individually learned song syntax correlates with individualized temporal combination selectivity in HVC neurons.