S. Allen Counter led an eventful life. He was a pathbreaking neurologist at Harvard Medical School.

His life’s passion, however, was to bring deserved recognition to the life and achievements of Matthew Henson, the explorer who traveled with Admiral Robert Peary to the North Pole.

“S. Allen Counter, a Harvard neurobiologist and explorer who reclaimed the reputation of Matthew A. Henson, a black explorer on Robert E. Peary’s 1909 expedition to the North Pole, and tracked down his descendants in Greenland, died on Wednesday at his home in Cambridge, Mass. He was 73.

“The cause was cancer, his daughter Philippa Counter said.

“Dr. Counter, a member of the Explorers Club, combined a scientific career with travel to the four corners of the earth. At Harvard Medical School, which he joined in 1970, his research on nerves and muscle synapses led him to such far-flung destinations as Ecuador, to study the neural damage caused by lead-glazing in the village of La Victoria, and China, to study acupuncture.

“One of his interests — discovering the cause of widespread hearing loss among the Inuit of Greenland — dovetailed with a historical mystery he hoped to solve. While dining with Swedish colleagues in the late 1970s, he was told that both Peary and Henson, Peary’s main assistant on all but one of his Arctic expeditions, had left descendants in northern Greenland, the product of their relationships with Eskimo women.

“Dr. Counter, who had been fascinated by Henson since childhood and had written extensively on the contributions of black Americans in remote places, made it his mission to track down their sons and descendants.

“In the summer of 1986 he traveled to northern Greenland, where his questions about “kulknocktooki,” or “dark-skinned people,” and the man known as “Miy Paluk” (“Matthew, the kind one”), led him and an interpreter to a remote settlement of some 30 people in the Inglefield Bay Area.

“There, an old man emerged from a wooden house and said: “You must be a Henson. You’ve come to find me.” It was Anaukaq, the son of Henson and Akatingwah, his Eskimo companion. Anaukaq was now 80 and the father of five sons, with 22 grandchildren.

“One of the great moments of my life was walking into that village,” Dr. Counter told The Boston Globe in 1986.”