FY2016 Annual Report

Neuronal Mechanism for Critical Period Unit
Associate Professor Yoko Yazaki-Sugiyama

Abstract

Songbirds learn to sing their courtship song from their tutor song experience intensively during development as humans learn to speak. Their early auditory experience shapes their brain circuits for forming a memory of tutor song, then would affect later period of motor song learning and higher cognitive functions. Our lab has been interested in how songbirds detect their own species song for song learning and how early auditory experiences shape neuronal circuits in the brain, namely how to form a memory of tutor auditory experiences. Based on the findings of last years, we tried to identify auditory neuronal circuits anatomically and physiological effect on auditory sensory activity of social interaction with tutor birds.

1. Staff

  • Dr. Makoto Araki, Postdoctoral scholar
  • Dr. Jelena Katic, Postdoctoral scholar
  • Dr. Takashi Kudo, Staff Scientist
  • Dr. Shi Yanagihara, Staff Scientist
  • Dr. Yuichi Morohashi, Technician

2. Collaborations

2.1 Luke Ramegy-Healry (U Mass) for GABA inhibitory control of auditory activity in zebra finch higher auditory cortical neurons.

3. Activities and Findings

3.1 Memory formations of early auditory experience in zebra finch song learning

Similar to human speech acquisition, vocal learning in songbirds is highly dependent on early auditory experience. During early development, juvenile songbirds listen to and form an auditory memory of the adult tutor song. Thereafter, they use this memory to shape their vocalizations in later sensorimotor learning. The auditory association cortex, called the NCM, is a potential storage site for tutor song memory, but no direct evidence has been found for a neuronal representation of this memory in juvenile songbirds. Here, we explored the neuronal substrate for tutor song memory by recording single-neuron activity in the NCM of behaving juvenile zebra finches. After tutor song presentation, a subset of NCM neurons began to exhibit highly selective auditory responses to the experienced tutor song. Moreover, blockade of GABAergic inhibition, as well as a sleep state, decreased the auditory selectivity to a specific song. Taken together, these results suggest that experience-dependent recruitment of GABA-mediated inhibition shapes auditory cortical circuits, and the tutor song memory is therefore sparsely represented in a subset of auditory cortical neurons. (Published in Yanagihara and Yazaki-Sugiyama, 2016).

3.2 Neuronal mechanism for species specific song learning in zebra finches

Juvenile songbirds learn vocal communication from adult tutors of the same but not different species. How species-specific learning emerges from the basic features of song prosody remains unknown. In zebra finch auditory cortex, we discovered a class of neurons that register the silent temporal gaps between song syllables, and were distinct from neurons encoding syllable morphology. Behavioral learning and neuronal coding of temporal gap structure resisted song tutoring from other species: zebra finches fostered by Bengalese finch parents learned Bengalese finch song morphology transposed onto zebra finch temporal gaps. During the vocal learning period, temporal gap neurons fired selectively to zebra finch song. The innate temporal coding of inter-syllable silent gaps suggests a neuronal barcode for conspecific vocal learning and social communication in acoustically-diverse environments. (Published in Araki et al, 2016)

4. Publications

4.1 Journals

  1. Araki M., Bandi M. M. and *Yazaki-Sugiyama Y. (2016) Mind the Gap: Neural Coding of Species Identity in Birdsong Prosody. Science 354: 1282-1287 Featured: Science 354: 1234-1235
  2. Yanagihara S. and *Yazaki-Sugiyama Y. (2016) Auditory experience dependent cortical circuit shaping for memory formation in bird song learning. Nat. Commun, doi: 10.1038/NCOMMS11946. (featured article)

4.2 Books and other one-time publications

Nothing to report

4.3 Oral and Poster Presentations

  1. Makoto Araki, Mahesh M Bandi and Yoko Yazaki-Sugiyama, Neural coding of species identity in birdsong prosody, Society for Neuroscience Meeting
  2. Takashi Kudo & Yoko Yazaki-Sugiyama, Early auditory experience modifies neuronal firing properties of neurons in zebra finch auditory cortex, Society for Neuroscience Meeting
  3. Gordon Research Conference -Auditory Systems Selected short talk ‘Mind the gap: Neuronal coding od species identity in birdsong prosody’, Bates College USA, July 2016
  4. 9th Avian Model Systems meeting ‘Chemogenetic control of neuronal activity in songbirds’, Taipei Taiwan, March 2016
  5. Symposium at 93rd Annual Meeting of Physiological Society of Japan, ‘Women Scientists Symposium: The analysis of principles underlying the neuronalnetwork formation in the developmental stage.’ ‘Early auditory experiences shape neuronal circuit to form auditory memory in zebra finch song learning.’, Sapporo Japan, March 2016

5. Intellectual Property Rights and Other Specific Achievements

Nothing to report

6. Meetings and Events

OIST Workshop: Developmental Neurobiology Course (DNC)

  • Co-organized with David Van Vactor, Ichiro Masai

7. Other

Nothing to report.