Activity dependent brain plasticity: does singing increase the volume of a song system nucleus? Theoretical comment...

The avian telencephalic song system, including nucleus high vocal center (HVC), is an important model for the study of brain plasticity. J. J. Sartor and G. F. Ball (2004) asked whether song activity itself could increase HVC volume (see record 2005-01705-022). They report that male starlings that sang more, motivated by gaining possession of a nest box in competition with another male, had larger HVCs than males that sang less. These results are suggestive but correlational. A more direct experimental approach will be required to establish that HVC size is activity dependent. Their experiment is an important first step, however. The song activity hypothesis merits continued investigation because of its potential to produce unique insights into naturally occurring brain plasticity.