An Anatomist Who Devoted His Life to the Beauty of Living Cells
Nakai Jun’nosuke (1918–2004) was an anatomist who spent his life facing the beauty of living cells and observing their subtle movements with unwavering attention.
Born in Kyoto, he entered the Faculty of Medicine at the University of Tokyo after studying at the former Daiichi High School. In an era when Japan was rapidly adopting analytical approaches from Western medicine, Nakai sought to understand cellular behavior not as “results” but as “process.” He established a method for isolating and culturing nerve cells and succeeded in time-lapse filming of single neurons, becoming a pioneer in the field of neuronal dynamics. In 1957, he was appointed Professor of Anatomy at the University of Tokyo. After retirement, he played key roles in building the foundations of medical education as Vice President of the University of Tsukuba and as the second President of Hamamatsu University School of Medicine. In his later years, he also served as an advisor to Hamamatsu Photonics K.K. and the JT Biohistory Research Hall, connecting scientific research with society.
Nakai gained international recognition for being the first in the world to successfully co-culture nerve and muscle cells and to demonstrate the formation of a functional neuromuscular junction. He carefully followed how a nerve fiber extends toward a muscle cell, forms contact, and begins to respond―clarifying the process of cellular interaction and synapse formation. This work was highly regarded, and in 1976 he became the first Japanese scholar elected as an Honorary Member of the American Association of Anatomists.
Yet what defined Nakai’s scholarship was not his achievements alone, but his way of facing the cell itself. For him, a cell was never a mere “specimen.” Each one lived its own time, revealing the presence of life through faint signs and subtle shifts. Nakai spent long hours at the microscope, watching closely as cells reacted, settled, and then moved again―never overlooking even the smallest tremor.
His students recall:
“Professor Nakai saw cells not as ‘objects’ but as ‘living beings.’”
“He often said, ‘I study because living cells are beautiful.’”
“His way of enjoying the unknown left a deep impression on us.”
These testimonies reveal that Nakai’s research was rooted not in systematizing knowledge but in a direct sensitivity to life itself. A similar sensibility can be found in his student Yoro Takeshi, whose Brain-Driven Society critiques human-centered thinking. The idea that life does not exist in isolation, but gains meaning through continual interaction with what surrounds it, aligns with the stance Nakai embodied at the microscope.
As an educator, Nakai conveyed this attitude directly to his students. He avoided giving excessive instructions, allowing them the space to think, choose, and struggle on their own. He believed that a researcher’s attitude mattered more than the quantity of knowledge. As a result, all eleven of his doctoral students later became professors. More than Nakai’s words, it was the way he lived as a researcher that was passed on to the next generation.
The Person Behind the Work
Taking a Leave of Absence for a Friend
During his high school years under the old system, one of Nakai’s exceptionally gifted friends fell ill with a mental disorder.
Nakai recalled a farm in Hokkaido where he had once stayed for a kendo training camp―a vast landscape surrounded by open fields, and a couple whose generosity and warmth had left a lasting impression on him.
Believing that his friend’s spirit might find rest in such a place, Nakai chose to take a leave from school and live with him there for a time.
In this quiet act of youthful compassion, one can already sense the “gentle courage to care for others” that would define his life.
The “Four Reductions” of the Faculty Meeting
While serving as head of the Department of Anatomy at the University of Tokyo, Nakai sought to correct the inefficiency of faculty meetings.
He introduced what he called the Four Reductions:
(1) Reduce the number of committees.
(2) Reduce the number of members.
(3) Reduce the frequency of meetings.
(4) Reduce the duration of each meeting.
Guided by his conviction that “the true duty of university teachers is to study,” this reform valued essence over form and left a deep impression on his colleagues.
Treating Technicians as “Collaborators”
In his research, Nakai regarded assistants and technicians not as subordinates but as collaborators.
He included their names as co-authors on papers and recognized their contributions with fairness and respect.
To Nakai, a technician was not a mere operator of instruments. Through years of practice, they had cultivated sensibilities that only time could teach―awareness of a tool’s temperament, the mood of materials, the subtle differences in light and humidity.
Even in the midst of repetitive work, they would silently ask themselves, “How can this be improved? Is this beautiful?”
Nakai saw in such “thinking hands” a form of wisdom essential to science itself.
He valued not only results, but the quiet weight of accumulated effort―the knowledge that resides in the work of each day.
“True Learning Is Understanding Another’s Pain”
Nakai often said, “True learning is the ability to understand another’s pain.”
In those words lay his belief that before one is a scientist, one must remain a human being―capable of empathy and imagination toward others.
For him, all scholarship and technique began with understanding people.
That quiet philosophy continues to live on, resonating softly in the hearts of those who follow in his path.
Editor’s Voice
When I was involved in research under Prof. Nakai, I had the opportunity to visit the laboratories of many outstanding researchers across Japan together with him. It was during those visits that I first realized something important: that researchers themselves can be as fascinating, rich, and deeply compelling as the research they pursue. It was a perspective I would never have noticed without meeting Prof. Nakai, and it became the starting point for seeing science as something shaped by a person’s stance and way of being.
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