Feinberg Prof. Toshio Narahashi, former chair of the pharmacology department, died of colon cancer April 21. He was 86.

Narahashi was internationally known for his work in neurotoxicology, the branch of medicine that studies the effect of toxins on nerve cells. He was a tenured professor at Feinberg for more than 35 years, spending 17 at the helm of pharmacology department.

Dr. William Lowe, Feinberg vice dean of academic affairs, presented Narahashi with an honorary plaque at a symposium recognizing his work in March.

“Dr. Narahashi has had a major impact in our understanding of the biology of ion channels and throughout his career he trained many individuals who are now having their own impact on the fields of neuropharmacology and neurobiology,” Lowe said in a news release. “The ceremony brought together many of Dr. Narahashi’s previous trainees to discuss their shared experiences, his more recent scientific explorations, as well as his impact on their career development.”

In 1964, Narahashi discovered how a highly poisonous neurotoxin found in puffer fish paralyzes parts of the nervous system. The discovery was the hallmark of years of research, which began when he received an undergraduate degree from the University of Tokyo in 1948. He moved to the United States in 1961 to pursue more research opportunities.

Narahashi is survived by his wife of 59 years, Kyoko, as well as his son Taro, daughter Keiko, son-in-law Peter Belamarich, grandson Micah and granddaughter Joy. Feinberg held a memorial service Friday on the Chicago campus.