From Hans Machemer

Memories about Yutaka Naitoh

(from Hans Machemer)

Yutaka Naitoh was the pioneering researcher of the electrophysiological control of behaviour in unicellular eukaryotes, such as Paramecium. As early as 1966 he discovered that the “reversal response” of cilia was caused by a depolarization of the membrane. Invited by Roger Eckert, UCLA, to the United States, he discovered in 1969 the bipolar mechanosensory organization of Paramecium.

Eagerly striving to deepen my understanding of unicellular physiology I became a postdoc in Eckert’s lab from 1971 to 1973, where I appreciated the elaborate intracellular electrophysiology established by Yutaka. When Yutaka returned to Eckert’s lab in summer 1971 together with his wife Toshiko and his son Takuya, the Naitoh- and Machemer-families became good friends so that – besides the enthusiastic lab work – we spent wonderful weekends exploring the nature throughout California (see some examples in the annex. "Oda" is the name of my daughter).

While Roger Eckert spent a sabbatical year in Munich (Germany) 1973, I increasingly followed Yutaka’s footsteps in exploring the sensorimotor organization in ciliates. After my return to Germany in August 1973 and after establishment of a work group at the Bochum University in 1975, I was happy to see at my lab coworkers and guests from Japan (Akihiko Ogura, Akira Murakami, Kazuyuki Sugino, Yasuo Nakaoka, Yashihiro Mogami, Keiichi Takahashi). Also Yutaka was our guest for scientific cooperation starting Sept. 1982. Here, he continued his work on Paramecium determining the reversal potentials of Ca- and K-currents under voltage clamp and correlating these with the equilibrium potentials of these ions. In 1990, Yutaka invited me to talk on cilia as membrane-controlled rotary engines at the International Congress of Protozoology at Tsukuba.

The last message I received from Yutaka was a colourfully printed New Year greeting from Dec.20, 2018 uncluding nice photographs and personal reflections about cosmic sight studies. I answered him by a personal letter of Jan. 10, 2019 and enclosed a photo of our that-time family.