Meeting Abstract
Zebra finches are commonly used to study vocal learning, which provides the basis of human speech and language acquisition. Here we describe the effects of alcohol on song learning and activation of the vocal circuit. Male juveniles learn to sing during a critical period when they first establish a tutor song auditory memory, and then learn to produce that song over a prolonged period of sensorimotor practice. Juveniles were provided free access to 3.5% alcohol during the song learning period (from 45 – 125 days of age), while control siblings received only water. Singing was recorded weekly during alcohol-free conditions, until adulthood. To evaluate the effects of alcohol on song we measured song stereotypy and the similarity of songs compared to tutors in experimental and control groups. Alcohol increased stereotypy of undirected (plastic) song and this effect was detectable within 10 days after the initial alcohol exposure. The similarity of pupil song at maturity to tutor song was diminished in the alcohol group, suggesting that alcohol either impaired the recall or imitation of the tutor template. We also note alcohol increased horizontal song transmission, where finches were more apt to learn from other juveniles. to assess the mechanism that may underlie these behavioral changes, finches raised to 70d were given 6.5% alcohol or water and sacrificed after intense singing. In-situ hybridization revealed that alcohol decreased song-induced expression of ZENK (egr-1) in Area X, a basal ganglia nucleus crucial for song learning. We suggest that alcohol affects vocal development by inhibiting a brain circuit required for vocal motor plasticity, thus limiting the bird’s ability to learn tutor song.
