‪Yoko Yazaki-Sugiyama, Ph.D.
Associate Professor
Neuronal Mechanism for Critical Period Unit
Okinawa Institute of Science and Technology

Transient auditory-motor projections subserving developmental song learning

Memory recall and guidance is essential for motor skill acquisition. Like humans learning to speak, male zebra finches learn to sing by memorizing a tutor’s song (TS) then vocally matching it in sequentially well-orchestrated auditory then sensorimotor developmental learning periods. However, the neuroanatomical substrate supporting auditory memory-guided sensorimotor learning has remained elusive. Previously, we found the small subset of neurons in the auditory forebrain area, caudomedial nidopallium (NCM) become to show selective auditory responses to a TS by exposing to tutor singing, suggesting neuronal substrate of TS memory. We further identified a transient neuronal projection into the motor control region, HVC, from those neuronal TS memory ensembles in NCM by an activity-dependent viral expression system in zebra finches. In turn, virally inducing cell death in TS responding neurons in the juvenile NCM impaired song learning, while the same deletion in adulthood had no such effect on faithful song production. Moreover, sequential song learning from two tutors of different species yielded distinct neuronal ensembles for two song memories, both of which retained connectivity to HVC into adulthood. Dynamic pruning of long-range axonal projections thus regulates auditory memory-guided vocal learning during a specific juvenile period in zebra finches. Persistence of exuberant connections with enriched experience in the same period may increase the capacity of song circuits in adulthood, implicating similar underlying mechanisms in human bilingualism.

Faculty Host: Kishore Kuchibhotla