Title: A neural clock underlying the temporal structure of an auditory memory

Abstract: Songbirds, such as zebra finches, store an auditory memory of their tutor's song and, over the course of several months during learning, gradually refine their own vocalizations to produce a close match to the tutor song. A young zebra finch can learn to imitate a song it hears only a few times, even though their songs are temporally complex and are extremely precisely reproduced. How is such a stable auditory memory of the tutor song formed? Song is controlled by a sparse neuronal sequence in the pre-motor nucleus HVC. The observation that local cooling of HVC slows the song suggests that timing is controlled by local dynamics within HVC. However, recent work also shows that disruption of HVC or its auditory inputs and outputs during tutoring impairs vocal learning, suggesting a role for HVC in tutor memory formation and recall. Here we propose a specific model by which neural dynamics in HVC form during tutoring and act as a precise neural clock, not just for singing, but also for laying down the auditory tutor memory and synchronizing the recall of the tutor memory during singing, allowing the temporally precise readout of vocal errors. Motivated by this hypothesis, we tested a critical prediction of our theory: that cooling of HVC during tutoring leads to a sped-up tutor song memory, analogous to slowing the motor of a tape recorder during recording and then playing the recording back at normal speed. We designed a modular thermoelectric cooling device and found that transient cooling during tutoring caused birds to produce faster imitations, consistent with our theory. This work gives insight into formation of auditory memories, and how they can be stably recalled later to guide precise sensory-motor learning.

Talk will also be available on zoom:  https://us02web.zoom.us/j/89238458002