Adult born neurons and the avian song system, zebra finches:  Songs serve important functions in many species, and at least one function for zebra finches is the means for the male to attract a female.  Male zebra finches learn their song from a tutor, who is typically the father.  The process of learning a song is analogous to language learning, where both the strong motivation to mimic, learn and practice produces greater fluency and precision.  When juvenile birds reach adulthood, the song they sing appears crystalized, remaining the same for the remainder of their adult lives.  Curiously, during their adulthood, there is ongoing neurogenesis in an area of the brain, HVC, that is instrumental in the production of this song.  Despite the fact that adult neurogenesis has been well-documented in this area for decades, it is not well known how nor to what extent these new neurons may benefit song production in the adult.  Our lab has discovered what we believe to be a new class of adult-born neuron in area HVC.  At this time, It appears to be uniquely identified by the expression of the phosphoprotein, DARPP-32, and we believe it may be an excitatory interneuron.