INDIANAPOLIS -- A doctor in Portugal is recruiting people through an Indiana hospital for a study on whether cells in nasal tissue can help repair damaged spinal cords.

Dr. Carlos Lima, a neuropathologist, says harvesting olfactory mucosa -- naval-cavity tissue with mucus-secreting glands -- and from a patient and putting it into his or her damaged spinal cord may be able to help regenerate spinal cells.

Lima already has led such a procedure on a Butler University student, Sarah Clay, who became a paraplegic in an ATV accident five years ago.

Clay flew to Portugal last year for the operation, called olfactory unsheathing cell implantation. She is now undergoing intense rehabilitation and has seen improvement.

"I can walk with ... braces, and I couldn't do that before," Clay told 6News' Stacia Matthews.

The idea behind the procedure is that the nasal tissue has nerve cells that can regenerate, Matthews reported.

"When you lose your sense of smell, it comes back. Those are nerve cells that you're looking for," said Clay, a pharmacy student. "They are nerve cells -- stem cells -- and they regenerate."

Lima is working with the Rehabilitation Hospital of Indiana to recruit patients for his next study.

"We're seeing some things that are interesting. They are hard to explain from the normal process of a spinal cord injury," the hospital's Annette Seabrook said.