1.Research Summary

Our group carries out basic research in auditory system with conventional as well as innovative technologies, focusing on the auditory peripheral organ, the cochlea. We have two groups, the Electrophysiology and Computational Science Group, and the Molecular Biology Group. These groups research complimentarily in our projects.
In order to analyze the mechanisms underlying functions of the cochlea, our lab is composed of the staffs and facilities to perform all of the electrophysiological, mathematical and molecular biological techniques. We conduct unprecedented unique researches including development of “state-of-the-art” methodology through the interdisciplinary collaboration with the top runners in different fields such as engineering and computational science.

2.Research Groups

• Electrophysiology and Computational Science Group
• Molecular Biology Group

3-1.Electrophysiology and Computational Science Group

Research subjects

• The mechanism underlying the highly positive potential of the cochlear endolymph.
  (Collaborative research with Division of Molecular and Cellular Physiology, Department of Pharmacology, Graduate School of Medicine, Osaka University, and Computational Biophysics Course, Graduate School of Natural Science, Kanazawa University)
• Traveling wave on the cochlear basilar membrane.
  (Collaborative research with the Optoelectronics field, the Department of Electrical and Electronic Engineering, Faculty of Engineering, Niigata University)
• Real-time measurement of local pharmacokinetics in the cochlea.
  (Collaborative research with the Inorganic Materials Chemistry Laboratory, the Department of Chemistry, Faculty of Science and Technology, Keio University)

3-2.Molecular Biology Group

Research subject

• Proteomic analysis of the molecular architecture maintaining the electrochemical properties of the cochlea.
  (Collaborative research with Bio-system pharmacology, Department of Pharmacology, Graduate School of Medicine, Osaka University)
• Glycomic analysis of the cochlea’s epithelial tissue essential for hearing.
  (Collaborative research with the Biochemistry Laboratory, the Department of Biology, Faculty of Science, Niigata University)
• Development of new deaf model mice by optogenetic approach.
  (Collaborative research with the Department of Psychiatry and Neuroscience, Faculty of Medicine, Keio University)

Please see our website for a detailed description of the Department of Molecular Physiology.

4.Research Results

[Area] Molecular physiology (Electrophysiology and Computational Science Group)

[Research subject]

Electrophysiological/computational science research on the mechanism underlying the high positive potential of endolymph

[Description]
In the cochlea of the inner ear, “the endolymph” exhibits a high concentration of K⁺ and a positive potential of +80 mV. We measure the environment of potential/K⁺ in the cochlear stria vascularis, an epithelial tissue essential for maintenance of the endolymph, by using a K⁺-selective double-barreled microelectrode technique. In addition, we are striving to unravel the mechanism underlying the positive potential by verifying the reproduction of our experimental results with mathematical models. We are now testing various hypotheses by employing a bidirectional approach with mathematical models and electrophysiological experiments.
http://www.ncbi.nlm.nih.gov/pubmed/25143138
http://www.ncbi.nlm.nih.gov/pubmed/22619324

[Photographs]

[Area] Molecular physiology (Molecular Biology Group)

[Research subject]

Proteomics analysis of the histological architecture of the cochlea and homeostasis for the electrochemical environment in the endolymph

[Description]
The cochlea is endowed unique histological architectures and electrochemical environment. Little is known about the underlying molecular mechanisms. We conduct proteomic analysis that focuses on the membrane proteins constituting the cochlear stria vascularis through the collaboration with Osaka university. Data analysis of the detected proteins reveals deafness related molecules and candidates of their regulatory factors.

[Photographs]

Molecular and Synaptic Mechanisms

Please see the Molecular Physiology website for a detailed description of our research.

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