Researchers Recreate Pain-Sensing Neurons

Researchers at the Harvard Stem Cell Institute and the Stem Cell and Regenerative Biology Department have successfully developed pain-sensing neurons from mouse and human skin cells, according to a report published in Nature Neuroscience in late November.

The study specifically aimed to simulate primary afferent nociceptors, very specialized pain-sensing neurons.

According to head researcher Clifford J. Woolf, a professor of Neurology and Neurobiology at the Medical School, the findings may lead to development of more effective pain medications, better methods to evaluate who is at risk for developing chronic pain, and ways to combat pain complications resulting from cancer chemotherapy.

“What we’ve been able to do with stem cell technology for the first time is recreate some of the key elements of the nervous system by taking one cell and turning it into a particular other cell,” Woolf said. “This enables us for the first time to really dissect how human neurons function in the nervous system.”

For Woolf, the study is a culmination of many years of research, previously done only in mouse cells.

“The fact that we can even create these cells with a human gives us the opportunity to study the mechanisms of the way human nervous systems work that haven’t been possible before,” Woolf said.

Tony L. Yaksh, co-director of the Pain and Symptom Management Core of the University of California at San Diego’s Regional Cancer Center, emphasized the study’s role in raising new questions for further research.

“I think this is highly innovative and an extremely well-done paper,” Yaksh said. “I’d say this represents a very concerted, well-organized group effort to define this very critical issue. It leaves you with more questions than before you read the paper, but it starts the ball rolling in a very exciting way.”

Yaksh also highlighted the importance of the study in streamlining gene-specific treatment.

“The significance is [that] this allows us to define a mechanism that may be relevant to pain transmission in humans without having to euthanize a human being,” Yaksh said.

Yaksh called attention to the study’s relevance to the issue of pain variance across individuals, manifested in either different pain thresholds or the different degrees to which patients experience postoperative pain.

“Some people with a certain genetic makeup tend to have worse postoperative pain,” Yaksh said. “This particular thing that Clifford [Woolf] has done is this: let’s take the people who have a worse pain state and let’s find out what’s different about their genes.”

The fabrication of pain-sensing neurons holds potential for individualizing analysis of pain felt by patients and developing more specialized treatment.