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Masaru Mimura, Professor, School of Medicine

Update: Aug. 26,2013

Uncovering the mysteries of the brain and mind

Many researchers at the Department of Neuropsychiatry bring a variety of perspectives to investigating the mysteries of the brain and mind, a vast field which encompasses research over a wide span of ages and disorders, from children to the oldest-old and from stress to dementia.

Researchers of the Department of Neuropsychiatry

When I returned to Keio in 2011 after about 20 years elsewhere, the Great East Japan Earthquake had just occurred, and even now providing mental care to disaster victims continues to be a major issue. In the summer of the same year, the Ministry of Health, Labour and Welfare updated the original list of Japan’s four major illnesses—cancer, heart disease, stroke, and diabetes—to include a fifth: mental illness. The body and mind are inseparably connected, and mental issues greatly affect our lives. Understanding mental issues in relation to the mechanisms of the brain, the basis of the mind, has become increasingly important.

Approaches to uncovering the mysteries of the brain and mind are wide-ranging and include gathering information by talking with patients, examining images of the brain, and carrying out laboratory experiments. These approaches are broadly classified into two categories: clinical research involving patients and basic research using laboratory animals.

Clinical research aims at improving techniques for the diagnosis of mental disorders and accuracy of treatment, and we actually learn a great deal from patients. It is based on a three-way collaborative effort between staff who design the research, graduate students who carry out the research, and patients.

On the other hand, in the case of basic research, one might question whether or not it is possible to investigate the human mind using lab animals such as mice. Mice do not use verbal communication and, according to observation, do not possess the ability for advanced social cognition, such as guessing how another is feeling from their facial expression. However, there are types of nonverbal behaviors and brain activities behind such behaviors which are similar between mice and humans. Fear, depression, and anxiety can be understood as behavioral patterns common to all creatures to avoid danger or as breakdowns in these patterns, and even with lab animals, disorder can be quite obvious from changes in their behavior.

With lab mice, gene manipulation and cell manipulation are also possible, allowing us to go beyond simple observation or speculation to investigate the causal relationships of a certain phenomenon. In our department, we conduct research on depression and anxiety from their causes to recovery processes and analyze them at the molecular and cellular level.


Student’s Voices
Keitaro Yoshida, First-year student, Master Course, Graduate School of Medicine

Manipulation of brain cells using light


I belong to the laboratory of biological psychiatry of the Department of Neuropsychiatry and am involved in research to reveal the neural network of depression using lab mice. Recording brain activity does not allow me to go beyond observation, so I use optogenetics, a technology that uses light to selectively control cell activity. With this technology, I can directly intervene in the brain’s neural activity to shed light on the connection between brain activity and depression.
Optogenetics is a leading-edge technology, and every day brings new discoveries. There is still a lot of room for new contributions, so even the ideas of an inexperienced researcher like me are adopted now and then in our team. It is so exciting as I can experience the joy of contributing to the team even as a student.

*This article appeared in the 2013 summer edition (No.279) of “Juku”.
*Position titles, etc., are those at the time of publishing.