R&D Spirits
Understanding the Brain—Exploring
the Mechanisms behind Neural Transmission
Keiichi Torimitsu
Executive Manager
Director of Materials Science Research Laboratory
NTT Basic Research Laboratories

The research of nano-bio science, a fusion of nanotechnology and bio-science, is beginning
to attract attention in the world of information-communications. This field, which includes
neural transmission mechanisms, is currently being researched by the Molecular and Bio-Science Research Group at NTT Basic Research Laboratories. To find out what possibilities thisseemingly non-NTT-related field of research holds and how it may change the future of both
NTT and society, we talked with Keiichi Torimitsu, the Group Leader of the Molecular and BioScience Research Group.

Searching for a biological-electronicinterface for information-processing
and health-care applications—Dr. Torimitsu, could you tell us about the section thatyou belong to and the roles that you perform there?
Well, to begin with, research at NTT Basic
Research Laboratories is centered on two main fields:
quantum materials and nano-bio science [1]. The
Materials Science Research Laboratory is concernedwith the latter, and I am the executive manager of thislaboratory. At first glance, it might appear that bioscience is not a field in line with the basic business ofNTT. But the mission that we have established for
ourselves is to create new materials and devices incombination with nanotechnology, which is a specialty of NTT, and to use these devices to promotetechnical innovation in the information-sharing society.
The Materials Science Research Laboratory is
divided into three groups. These are the Thin-Film
Materials Research Group, which targets materials
such as gallium nitride, aluminum nitride, and diamond for high-output systems; the Low-Dimensional
Nanomaterials Research Group, which researches
carbon nanotubes and the formation of their circuits;
and the Molecular and Bio-Science Research Group,6

which deals with nerve cells. These apparently disparate groups do have a common thread, and that’s
the research of functional materials. That is why I
take a comprehensive view of their research results—
I believe that these three groups, in combination, cancome up with new and innovative devices and sensors. By the way, I also lead the Molecular and BioScience Research Group while managing these threegroups in unison.
—What specific research is the Molecular and BioScience Research Group involved in?
We are involved with several projects in parallel.
The first of these is the generation of artificial neuralcircuits. In this project, we experiment with the intentional growth of nerve tissue to examine the relationship between neural circuits and memory and learning
functions. This research requires an understanding ofneural-circuit functions, and for this reason, we are
simultaneously developing tools for measuring thosefunctions in an electrical and electrochemical manner.
This is actually the work of our second project.
Next, in order to investigate the functions possessedby neural connections, or synapses, in nerve cells, weneed to be able to visualize their behavior under various conditions, and we are developing an electrochemical measuring tool for this purpose. This is an 8 × 8array of enzyme-treated electrodes on a substrate,
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10 nm
Au electrodeDNA

Si-Si-Si-Si-SiSGD

ITO arrays (64 channel)
50 µm 250 µm
Glass substrate
Insulator* 8 electrodes wereselected from the array.

ITO: indium tinoxideFig. 1. Nano-bio science: towards a bio-information link through a biological-electronic interface

which we use to determine the spatial and temporal distribution of neurotransmitters released from the brain’s
hippocampus. With this information, we can investigate the functions and reactions of specific regions of
the brain. This is the work of our third project.
Finally, our fourth project is the study of brain
receptors. As you know, brain signals are transmitted
through the process of converting electricity into
chemical substances and back into electricity. Theintermediary in this process is a receptor, but much ofits function is still unexplained. In this project, we
focus on the receptor protein and research its
response to stimuli using an atomic force microscope.
These projects are all concerned with interaction
between nerve tissue and substances. If we can
explain this interaction, we may be able to explain themechanism behind human information processing,which might then lead to a technological revolution incommunications in the information-sharing society.

grid computing. That being said, it is going to takesome time to reach that point, at least 10 to 20 years.
But during that time, we will come to understandmany things, and I think that from time to time wewill be able to provide the world with various bioproducts that make use of that knowledge. The most
likely target of such products is the health care field.
Our research on nerve cells is actually research on
biological-electronic interface technology. If we canmake this technology practical, we can envision its
use in health care, medical treatment, and sensing by
providing a bio-information link between people andcomputers. We think bioproducts of this type might
be attainable within ten years. Although NTT is notdirectly involved in the business of health care, it
should be able to cultivate new business areas bydeveloping new devices and providing health-related
information-communication networks.
—What specific bioproducts are being considered?

—In what ways might this research benefit society?
Well, if we can clarify the mechanisms underlying
memory and learning in the brain, the application ofthat knowledge might give birth to new forms of information processing. It might even result at long last in
biocomputers, which have long been the subject ofmuch research. And it could even lead to more efficientVol. 3 No. 5 May 2005

For example, we can imagine the realtime monitoring of health-related information by attaching a verysmall device to the human body or embedding one in
it. This could be part of a tailor-made health care system that sounds an alarm whenever an abnormal condition arises. And if this system can be further
enhanced, it might prove useful in the treatment of7

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Bio-technology

Nano-technology
Bio-friendly
nanodevice formation

Protein analysis andfunctions
FusionNano-bio-device
NanoEYE

Rhodopsin

NanoEAR

Odor protein

NanoNOSE
Molecular
circuitNano-EYE

Molecular circuit

Communication with extended Humanfive senses
Five-senses
communication

Nano-BRAIN

Network

NanoNOSE• Medicare system• Personal database

Think communication

Healthy and comfortable Life

Ultimate communication

Tailor-made medical careFig. 2. Strategy of Nano-bio research.

diseases such as Parkinson’s disease. A person with
Parkinson’s disease loses control of body movement
as the secretion of a particular neurotransmitter
becomes impaired. If a device were able to detect thelack of such neurotransmitter production, it could
stimulate nerve cells in a specific region of the brain
and promote the secretion of that chemical. This isquite possible, at least from a theoretical point ofview.
Another application would be to transmit visual oraural signals directly to the brain to give visually oraurally impaired people an artificial sense of vision orhearing as a substitute or supplement. These nanodevices, which we call “nano-eye” and “nano-ear,”
could lead to even more advanced products such as
artificial communications based on the five senses
and even “synchronous communications” whereby acertain image can act as a trigger for establishing alink with another party.
—What has been the most important technicalaccomplishment in this research?
That would be the 8 × 8 electrode substrate that I
mentioned earlier. This is indeed a biological-electronic interface, but I must admit that it is not especially new. Similar tools are being developed andimplemented in Germany and by other companies inJapan. But from a functional point of view, I think weare out ahead. At the experimental level, our device
can record data continuously for a period of about 50
days, and in terms of simply exchanging information,
it can be used for about six months. There are noother devices of this type that can be used for so long.
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If we can continue to decrease the size and raise theperformance of this device, it should expand to various types of nano-devices in the future.

Attracting worldwide attention by superior
fine-processing technology and an original
approach—Dr. Torimitsu, what are some recent trends in nanobio science?
In research targeting nerve cells and receptors as weare doing, Oxford University in the U.K. is analyzing
receptor functions at the molecular level, while theUniversity of Basel in Switzerland is performing
structural observations by atomic force microscopy
and Newcastle University in the U.K. is concentratingon nerve cells from a health care perspective. There isalso research in this area at universities and government-related institutions in Sweden, Canada, Australia, and other countries, but I would say that there
is no organization covering as wide a research area as
ours. And in the United States, the scale of research islarge, but the approach taken there, if anything, ismore oriented toward commercialization than fundamental research. The trend there is to create biodevices using existing technology.
—What is the position taken by NTT Laboratories inthis regard?
A truly unique position. NTT, needless to say,excels in fine-processing technologies for the development of LSIs and other advanced devices. Bringing
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bio-science knowledge and techniques to this area as
we are doing is an approach that cannot be foundelsewhere. The general approach to research that
includes different fields of study as in nano-bio science is to have that research performed jointly by specialized research institutions. In our case, in contrast,
a single research group deals with both bio-scienceand nanotechnology. This is our most outstanding
feature and strength.
—Are you nevertheless involved in any collaborative
research with other institutions?
With the idea that two groups with complementaryknowledge and strengths can go far, yes, we are
involved in various joint-research projects. For example, a branch of the Institute of Medical Science of the
University of Tokyo has been set up in the Materials
Science Research Laboratory, and overseas, a branchof our research laboratory was set up last year at
Oxford University where I have become a guest professor. We are also working with universities in Sweden. We are planning to collaborate with several otherinstitutions in the near future.
—What has been the response so far, both from insideand outside Japan, to your research results?
We have received various acknowledgments of ourwork. The year before last, we received an award fora new method of measuring neural activity in relation
to magnesium from the respected Gordon Research
Conference in the United States. Participation in thisconference is generally by invitation only, and it isconsidered to be a gateway to joining societies in thisfield. We were very glad to have been recognized inthis way. We have also been interviewed by reportersfrom Newsweek, Time, and other magazines for special issues on nano-bio science, and researchers in thefield of information processing, such as SIGGRAPH,
have shown great interest in our results to date.

Aiming to contribute to informationcommunications and health care: the two
major industries of the 21st century—Dr. Torimitsu, could you tell us something about
your academic background?
My background is actually not in the biological sciences, but rather in engineering. My university major
was instrumentation engineering, and in our researchlaboratory, one of our measurement targets was plant
physiology. That was during a time when many people warned of an imminent food crisis, and it wasthought that growing larger plants using engineering
Vol. 3 No. 5 May 2005

techniques was worth a try. Our research in thisregard focused on the relationship between the electrical properties of mung bean root and its growth,and we found that growth could be significantly promoted by applying a certain voltage. This result cameto be used by a certain company in actual agricultural production. As I was just a student at the time, thatin itself—the achievement of actually useful
results—was very satisfying, but looking back, it
might not have been such a bad idea to apply for apatent. For my doctoral thesis, by the way, I measured
the chemical shift of phosphoric acid in cell vacuoles
and cytoplasm in order to estimate intracellular pH
using nuclear magnetic resonance. My goal here wasto analyze and explain the mechanism behind the way
a cell keeps its environment fixed in the face of external stress.
—What research activities have you been involved
with so far?
My first job at NTT was the preparation of soil aspart of bio-research. I should mention here that 1986,
the year that I entered NTT, was the same year that
NTT Laboratories embarked on bio-research. There
was consequently almost a complete lack of knowhow and facilities to support this research, and I was
first sent to the University of Tokyo for one year as aform of preparation. I received my instruction there
from then Assistant Professor Jun Fukuda (now professor at National Defense Medical College) under
the direction of Professor Masao Ito, a world authority in brain research and now a Group Director at the
RIKEN Brain Science Institute. My research theme
was to control the growth of nerve cells, which is usually a random process, using semiconductor fine-processing technology. After returning to NTT, I was
given the chance to undertake actual research whilesetting up facilities for NTT Laboratories, but thistime, I was sent to the U.S. National Institutes of
Health for about a year and a half starting in 1990.
My research there involved the measurement of aneurotransmitter called gamma aminobutyric acid
(GABA). This research, which continues to this day,relates to the development of sensors based on electrode substrates, which I talked about earlier. I cantherefore say that my research activities have always
centered on one major theme, namely, the control ofcell growth. One part of this research has been to
examine the correlation between fine-processing
technology and cell growth.
—What, in particular, have you been pursuingthrough your research?
I have been looking for the answer to the very sim9

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ple question: “How does the brain remember?” Man
has created an artificial brain called the computer,which, in one sense, far exceeds the ability of thehuman brain, but in another, falls far short. Consider
the task of recognizing a particular person, which is aform of information processing. When you encountersomeone who is included in your memory, you generally need only a few tens of milliseconds or at mosta few seconds to be able to recognize that person. A
computer, on the other hand, requires several minutesat best. What is the source of this difference? While itis known that the human brain is vastly different froma computer, I would still like to know what kind of
information processing is actually performed by thebrain. My research has centered, in particular, on mydesire to explain those mysterious parts of the brain
involved with memory and learning.
For that matter, there is also the question of “Whatdoes it mean to be alive?” This may sound a bit childish, but when you are involved with biology, fundamental questions like this one tend to bother you quite
frequently. For example, it is possible with current
technology to measure the behavior of even a single
cell receptor. It is also possible now to artificially prepare deoxyribonucleic acid (DNA), the source of life.
These, however, are not “living things,” and you
sometimes wonder what is the difference between
them and actual living things. I find this question very
interesting.

ing our research more widely acknowledged both
inside and outside the company. Nano-bio science is aminor field at NTT, and to gain a more solid foothold,we must endeavor from time to time to explain what
it’s all about and convey its value. At the same time,
we must make our research attractive to outside organizations and establish its position clearly.
I mentioned earlier that I undertook the research of
bio-science with a background in engineering. My
research today still involves both these fields. I also
have many opportunities to talk with experts in medicine and chemistry. These experiences have allowed
me to see how different fields come to view the samething in different ways. For example, when discussing
the same substance, an engineer may view it in termsof its electrical properties, while a bio-scientist may
consider only its functional aspects. A chemist, moreover, may see only its composition or reactive properties. In short, the language used to describe the samething can differ from person to person even if thatthing is sitting right in front of their eyes. Of course,
this may only be a case of different means of expression, but it can nevertheless cause an unexpected bottleneck in actual joint research. I feel a need for more
researchers who can talk in more than one “language”
much as I have had to do. While it would be an exaggeration to say that I am a bridge between engineering and bio-science, I sometimes think that perhaps
that should be my personal mission.

—How would you like to see this research develop
over the years to come?

—What is your ultimate goal as a researcher?

To begin with, I would like to see it become truly
useful for the health care and medical treatment
fields. It would also be nice if it could generate new
business opportunities for NTT. In this way, ourresearch should become part of information communications and health care, the two major industries ofthe 21st century. But as I mentioned earlier, it’s goingto take at least ten years for us to reach that point. Furthermore, there is the economics-related issue of how
to achieve a good balance between corporate profit
and public good in terms of research results. I cannot
solve all of these problems on my own, but I hope tobe part of their solution as my fellow researchers
increase in number.

Having a strong will: an essential attribute ofresearchers—Dr. Torimitsu, what are some current issues in yourresearch work, and what are your aspirations for the
future?
One great concern of mine is how to go about mak10

I really haven’t thought much about an ultimate
goal, but in terms of a long-term outlook, I would liketo uncover the mechanisms behind brain activities
such as recognition, memory, and learning. Perhaps I
am being too naïve, but I would like to understand thefoundation of brain activities that have defied explanation. Of course, I would want to produce usefulbioproducts along the way, and this long-term goal is
not to say that I have no interest in the businessaspects of our research. As a researcher, however, I
must not forget the search for scientific truth, whichshould anyway turn into something useful for people
in the form of health care or medical treatment.
—What is it like working at NTT Laboratories?
From the perspective of my research field, I find it
unique that NTT places importance on the public
good despite being a private company. I believe that
research undertaken not only with an eye to the market but also out of concern for the needs of people canonly happen in an organization like NTT. At the sametime, when our research enters the implementation
stage, the key technology will be fine processing,
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which is quite a different field from bio-science, but
is NTT’s specialty. We are also blessed at NTT withexcellent facilities and research funding. All in all,from the viewpoint of our group, NTT Laboratories isthe closest thing to an ideal research environment. To
be able to pursue research that one likes in an environment such as this one is very gratifying.
—Could you leave us with a message for young
researchers?
Yes, I would love to. My experiences have told methat if you have the determination to keep moving in
the direction of something that you want, there’s agood chance that you will eventually get it. Having astrong will and a deep desire for something gives you
the power to bring the people around you to your side.
It also has the power to reveal your latent abilities.
The most important thing for you as a researcher to
do is to let other people know what it is you want topursue. If you do that well, then I think you cannot
help but reach your desired goal eventually even if
some mishaps occur along the way. That is the kindof researcher that I myself aspire to be.
Reference[1]

K. Torimitsu, “Nano-Bio Science,” NTT Technical Review, Vol. 2,
No. 2, pp. 12-20, 2004.

Vol. 3 No. 5 May 2005

Interviewee profile■ Career highlights
He received the B.E., M.E., and Ph.D. degrees in
instrumentation engineering from Keio University,
Yokohama in 1980, 1982, and 1986, respectively. In
1986, he joined NTT Basic Research Laboratories andworked in the bio-computer project. His research interests range from neuroscience including signal transduction, neuro-imaging, and neurochemistry to surface
science and molecular science. He is currently focusing
on nano-bio science and nano-bio device fabrication.
He studied cell physiology and developed a novel measurement system using magnetic resonance spectroscopy from 1980–1986. From 1986 to 1987, he studied neurophysiology at the Laboratory of Physiology,
Faculty of Medicine, the University of Tokyo as aguest researcher. For the year 1990–1991, he was a visiting researcher at the National Institute of Health andstudied GABA physiology at the Laboratory of Neurophysiology, NINDS. From 1997–1998, he was a guest
researcher at National Institute for Minamata Disease.
He is now a Visiting Professor in Physics at Oxford
University. He received Research Awards from NTT
BRL in 1993, 1998, 2003 and the Distinguished Awardin 1994. He received the Poster Award at the Electrophoresis’99 and the SLOWMAG Award at the Gordon Research Conferences in 2002. He is a member of
the Society for Neuroscience, International Brain
Research Organization, Japan Neuroscience Society, etc.

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