When birds were stimulated with playbacks of recorded
song, thousands of transcripts were upregulated or
downregulated , and analyses of their genomic
sequences revealed that roughly two-thirds of the downregulated
transcripts were non-coding RNAs. Furthermore,
known and novel microRNAs were found to be
expressed in the auditory forebrain, and their binding
sites were detected in the untranslated regions of
regulated genes.