- Spinal cord injuries are much more common than one might expect. Around 1 in 50 people have them in the United States alone. As a result, finding a cure would be life-changing for millions of Americans.
- Dr. Michael E. Selzer has been studying this topic for nearly 40 years. He provides insight on how a cure could be developed by looking at an animal capable of repairing its own spinal cord.
- The sea lamprey, a species of deep sea fish, is capable of regenerating a severed or broken spine. By looking at its genome, scientists hope to one day discover a method to apply the lamprey’s healing capabilities to humans.
In 1983 in Danville, Kentucky, a railroad worker was finishing his shift and getting off the engine when he stepped into a hole. He heard two resounding cracks as the third and fifth disks in his lower back ruptured. Over the next two years, the pain from the injury increased to the point where he was unable to walk. This man, my grandfather, underwent extensive surgery which required the removal of the discs and the fusing of some of the remaining vertebrae. While he eventually regained the ability to walk, he never fully recovered from the injury and the pain has persisted to this day.
According to a 2013 survey by the Christopher and Dana Reeve Foundation, 1 in 50 people live with paralysis in the United States, which translates into nearly 5.5 million people. Humans and other mammals seldom regain full mobility naturally after such injuries. However, a few select species can easily recover from far more critical spinal damage.
The eel-like lamprey, an obscure species of fish, last shared a common ancestor with humans some 550 million years ago. Its nightmarish appearance and parasitic nature make it the ideal villain of a horror film. Instead, this curious creature now finds itself the protagonist of an unfolding tale of medical mystery.
The sea lamprey feeds by attaching itself to other fish by its toothed, funnel-like sucking mouth. However, scientists do not just study this species for its gruesome feeding habits. They are also interested in its unique ability to recover from paralysis caused by a severed spine. This ability seems like something out of science fiction, similar to the regeneration powers of Wolverine from the X-Men. But this is fact, not fiction.
The discovery of the lamprey’s spinal regeneration ability begs several questions: How does it work and how could an understanding of this mechanism help people who have suffered spinal cord injuries?
For nearly 40 years, Michael E. Selzer, M.D., Ph.D., a neurologist and director of the Shriners Hospitals for Children Pediatric Research Center, has been exploring how sea lampreys’ regeneration abilities might help mammals recover from spinal cord injuries. Such a discovery would have tremendous real world applications.
In the 1980s, scientists discovered genetically-influenced material in humans that appeared to inhibit spinal regeneration. For years, scientists conducted tests in genetically engineered mice that lacked these inhibitory molecules. Dr. Selzer said while the research showed recovery could be improved in mice, “none of the discoveries translated to humans.” The situation turned out to be more complex than anyone had previously thought.
The lamprey, explained Dr. Selzer, “has pretty much all the molecules that were thought to be inhibitory to regeneration.” His lab tests the lamprey’s ability by making small incisions to the spine, allowing the scientists to observe recovery. They look at how lampreys overcome the inhibitory factors in order to allow regeneration to occur. At the same time, collaborating labs are attempting to discover why regeneration does not happen spontaneously in humans. According to Dr. Selzer, “By studying why some animals cannot regenerate and why some animals can regenerate, we hope to find answers to some of the riddles that have been plaguing the field.”
In the future, Dr. Seltzer is hopeful that “we will be able to make progress toward finding a cure for spinal cord injuries.”
Dr. Michael E. Selzer, M.D., Ph.D., serves as Director for the Shriners Hospitals for Children Pediatric Research Center. He is also a professor of Neurology. Dr. Selzer has been studying sea lampreys and paralysis for nearly forty years, where he has focused on uncovering the science behind the lampreys regeneration and various human applications.
Denny, Diana. “Genes That Aid Spinal Cord Healing in Lamprey Also Present in Humans, MBL Team Discovers.”
Genes That Aid Spinal Cord Healing in Lamprey Also Present in Humans, MBL Team Discovers, Marine Biological Laboratory, 15 Jan. 2018, https://www.mbl.edu/blog/genes-that-aid-spinal-cord-healing-in-lamprey-are-also-present-in-humans-mbl-scientists-discover/.
Herman, Paige E., et al. “Highly Conserved Molecular Pathways, Including Wnt Signaling, Promote Functional Recovery from Spinal Cord Injury in Lampreys.” Nature News, Nature Publishing Group, 15 Jan. 2018, https://www.nature.com/articles/s41598-017-18757-1.
Chief Editor: Sophie Zhang
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This article was written by Jack Bobo. Jack and the cSw student editing team would like to thank Sybil Barnes for serving as a mentor on this story. Sybil is the Assistant Director for Digital Communications at the Federation of American Societies for Experimental Biology.
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