The same cells that give Darek Fidyka his sense of smell are also helping him walk again.The Bulgarian man, who was paralyzed after a knife attack in 2010,can walk after doctors in Poland transplanted nerve cells from his nose into his severed spinal cord. The successful operation was the first of its kind for regenerative medicine, and Fidyka is believed to be the first man to walk again after having a completely severed spinal cord.The Nose Knows?We owe our sense of smell to a pair of nerve cell bundles called olfactory bulbs, which reside on the underside of our brains behind our eyes. These structures help us smell grandma’s apple pie, but they’re unique for another reason: They’re one of the few known parts of the nervous system that regenerates throughout life.Doctors wanted to harness the regenerative capabilities of olfactory nerve cells, so they removed one of Fidyka’s olfactory bulbs in an operation two years ago. They took olfactory ensheathing cells from the bulb, and grew these regenerating cells in a petri dish. After two weeks, doctors injected the nose cells into the spinal cord. Doctors also transplanted four strips of Fidyka’s ankle nerve fibers to bridge the 8-milimeter gap in his severed spine,and allow a path for the cells to grow.Within three months, the treatment was reaping rewards. Fidyka — paralyzed from the chest down — regained feeling in his lower extremities; his left leg developed muscle mass; and bladder, bowel and sexual functions even returned, theBBCreports. Most importantly, hecan now walk once again with the assistance of a frame. Researchers published their results Tuesday in the journalCell Transplantation.