FY2018 Annual Report

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


Songbirds learn to sing their courtship song from their tutor song experience intensively during development as humans learn to speak. Juvenile birds learn songs intensively from social vocal communications with tutor birds (normally their fathers), while they learn little from passive auditory experiences. Our lab has investigated the neuronal mechanism underlying how the same auditory experiences would be formed as memories for song learning depending on behavioral condition of juvenile zebra finches. We have focused on neuromodulatory functions which regulates attention and elucidated the neuronal activities of the noradrenergic nucleus, Locus Cereleous (LC), during song learning. Neurons in the LC showed auditory responsiveness to the song playback from the speaker, however exhibited greater responses to tutor singing. We also found anatomically that LC neurons project to the zebra finch higher auditory cortical area which has been suggested to be a brain locus of tutor song memory formation. Taken together we suggest that attention changes by social interaction with tutors leads to altering neuroodulatorory regulation of auditory activities of higher auditory cortex, that would result in intensive memory formation with social vocal communications.

1. Staff

  • Dr. Makoto Araki, Postdoctoral scholar
  • Dr. Jelena Katic, Postdoctoral scholar
  • Dr. Zachary Bell, Postdoctoral scholar (until July 2018)
  • Dr. Takashi Kudo, Staff Scientist (until August 2018)
  • Dr. Yuichi Morohashi, Technician
  • Anna Kuneji, Techncian (from July 2018~)
  • Chie Edwards, Research Unit Admiistrator

2. Collaborations

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

    2.2 Jon Sakata (McGill Univ) for innate restriction in bird song learning

      2.3 Takao Hensch (WPI-IRCN, University of Tokyo) for regulation of the timing critical period by neuronal inhibitory function development (Supported by OIST KICKS grant)

        3. Activities and Findings

        3.1 Social interaction modulating auditory neuronal activities

        Songbirds are learning to sing from auditory experiences of singing of tutor birds during development. Juvenile birds intensively learn from the auditory experience through social interactions with tutors, while they learn little from passive auditory experiences, such as playback from a speaker. However, underlaying neuronal mechanism for social interaction dependent song learning has yet to be elucidated. In previous years we showed that a subset of neurons in the higher auditory cortex of juvenile zebra finches exhibit highly selective auditory responses to the tutor song after song learning, (Yanagihara and Yazaki-Sugiyama, 2016), and that the selective auditory response are enhanced by the presence of tutor birds (Yanagihara and Yazaki-Sugiyama, 2018). To see how neuronal auditory activity changes with interaction with tutors we further investigated the neuronal activities of LC, the noradrenergic nucleus by assuming tutor presence alter juvenile attentional level which leads to releasing of noradrenaline. We found that LC neurons showed auditory responses to song playback as well as greater responses to tutor song singing. LC neurons, which were activated by hearing of tutor singing, project to the higher auditory cortex. Taken together these suggests neuronal activity changes of LC neurons by attentional level alteration by social interaction with tutors regulate auditory neuronal activities in the higher auditory cortex neurons of juvenile zebra finches, that may result in forming a memory of tutor songs.

        3.2 Identifications of two complemental neuronal circuits for individual varieties and species identities

        Continuing from FY 2017 we have tried to anatomically identify the two categories of neurons in the brain area, called Field L, which is homologous to mammalian primary auditory cortex.

        By combining the tissue clearing technique, X-Clarity, and virus vector mediated fluorescent protein expressions, we visualize the anatomical structures of neurons in the primary auditory cortex anatomically and categorized them into group with their cell body shape and axon projection patterns (Fig 1). We are further trying identifying neurons anatomically after intracellular recording of their auditory physiological properties to match with the categorized group in volume data.

        4. Publications

        4.1 Journals

        Nothing to report

          4.2 Books and other one-time publications

          Review Yazaki-Sugiyama (2019) Neuronal mechanisms regulating the critical period of sensory experience-dependent song learning. Special Issue in Neuroscience Research, doi: neures.2018.11.002

          4.3 Oral and Poster Presentations

          1. Makoto Araki & Yoko Yazaki-Sugiyama, Intracellular and morphological bases for neural activities used to detect song temporal patterns in the primary auditory forebrain of zebra finches, The 41st Japanese Neuroscience Meeting, Kobe, July 2018
          2. Jelena Katic & Yoko Yazaki-Sugiyama, Attentional control of song perception in zebra finch song learning, The 41st Japanese Neuroscience Meeting, Kobe, July 2018
          3. Makoto Araki & Yoko Yazaki-Sugiyama, Morphological identification of zebra finch auditory cortical neurons for parallel information processing in song learning, Annual meeting of Society for Neuroscience, Nov 2018
          4. Jelena Katic & Yoko Yazaki-Sugiyama, Selective response of locus coeruleus neurons to extended live tutor singing in zebra finches during song learning, Annual meeting of Society for Neuroscience, Nov 2018
          5. Special lecture at 5th annual meeting of the Society for Bioacoustics, Innate and acquired auditory neuronal pathways for zebra finch song learning’, Kumamoto Japan, Dec 2018
          6. Symposium at 41st annual meeting of the Molecular Biology Society of Japan “A challenge to unveil molecular mechanisms underlying appropriate selective responses to the environmental information”, ‘Innate and acquired auditory neuronal pathways for zebra finch song learning’, Yokohama Japan, Dec 2018
          7. Birdsong 8: “Out on a Limb- unpublished data and new theories”, ‘Social interactions regulate auditory memory formation in zebra finch song learning’, San Diego, USA, Nov 2017
          8. Cold Spring Harbor Asia, ‘Social interactions regulate auditory memory formation in zebra finch song learning’, Awaji Japan, Sept 2018
          9. Symposium at 41st Annual Meeting of Japanese Neuroscience Society “Coding in sensory systems”, ‘Innate and acquired auditory neuronal pathways for zebra finch song learning’, Kobe Japan, July 2018
          10. Symposium at 11th FENS Forum in Neuroscience “Ethology and Evolutions” ‘Neuronal mechanism for bird song learning under innate restrictions’, Berlin, German, July 2018

          5. Intellectual Property Rights and Other Specific Achievements

          Nothing to report

          6. Meetings and Events

          6.1 OIST Workshop: Developmental Neurobiology Course (DNC)

          • Co-organized with David Van Vactor, Ichiro Masai

          7. Other

          Nothing to report.