Long-term maintenance of song in adult zebra finches is not affected by lesions of a forebrain region involved in song learning

Abstract

The long-term maintenance of stable song patterns produced by adult male zebra finches depends upon auditory feedback. It is not known which song-related brain areas process this auditory information, in part because previous functional studies in adult birds have not been of sufficient duration to detect behavioral changes that might result from interference with auditory feedback mechanisms. In the present study, adult males were subjected to bilateral lesions of a nucleus known to be necessary for auditory-based song learning, the lateral portion of the magnocellular nucleus of the anterior neostriatum (IMAN). Songs were then recorded over a period of time during which deficits due to removal of auditory feedback become apparent. Our data suggest that the IMAN does not mediate the stabilizing influence of auditory feedback on adult song production. That is, while deafening produces alterations in song structure within 16 weeks, bilateral destruction of the IMAN did not produce any substantial changes in song over this same period. These results extend a previous report by Bottjer, Miesner, and Arnold, Science, 224, 901-903 (1985) and suggest that the pathways through which auditory feedback affects adult song behavior do not involve the IMAN.