A<unk><unk> , also known as a<unk>  <unk> , is a series of discrete brain nuclei involved in the production and learning of<unk>  in<unk> birds. It was first observed by Fernando Nottebohm in 1976 in a paper titled "Central<unk>  of<unk>  in the canary, Serinus canarius", published in the Journal of Comparative Neurology.
Song control system
Rhythm interpretation
Multi-access key
Input and output 
Chemical nomenclature
Anatomical terminology
EFAR System Model
Reward system