EAPSI: How Early Experiences in a Critical Life Stage Cascade into Stereotyped Adult Singing Behavior in Songbirds

Edwards Jacob, Fort Collins CO

Investigators

Abstract

Infants pick up their native language with remarkable ease, whereas learning a second language in adulthood is laborious. This period of heightened sensitivity in youth, often called a ?critical period?, is a common feature of animal development across diverse taxa. Similarly, many songbird species learn their characteristic song during a critical period, beyond which no further learning can occur. Much work has been done on the molecular and environmental drivers that open and close the song-learning critical period, but it is not clear how variation in the quality of the juvenile?s experience influences the timing of this important developmental phase. In collaboration with Dr. Yoko Yazaki-Sugiyama at the Okinawa Institute of Science and Technology, this project will investigate how such experience alters plasticity in the brain. Understanding this process has important therapeutic implications for treating early language acquisition disorders, and potentially a range of other early-life social learning disorders. Understanding the temporal dynamics of the song-learning critical period has further potential to explain how constraints on neural plasticity develop and evolve. Zebra finches undergo a triphasic critical period. This consists of a sensory phase where song information is encoded in memory, a sensorimotor integration and refinement phase, and a period of overlap. Using fine-scale neuronal silencing techniques developed by Dr. Yazaki-Sugiyama, the project will explore the relative contribution of each phase to the timing of later phases and song crystallization. This will be the first study to selectively and reversibly perturb individual components of the critical period to determine their influence on the timing of critical period closure. Further, the project will generate song data as well as brain anatomical data to connect behavioral outcomes to their underlying neural mechanisms. Such work is needed to understand how critical periods and constraints on plasticity evolve, and to what degree they can be manipulated. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.