S u m m a r y :
Geckos growing back their tail might possibly be used to develop spinal cord treatment in humans, says new research that points at the special stem cells behind this superpower. The findings are published in the Journal of Comparative Neurology.
When A Gecko’s Tail Comes Off
Have you ever seen a lizard grow back its tail after losing part of it? A most marvellous ability, albeit gross, and maybe a little scary. Ever wondered how this happens? New research conducted by Matthew Vickaryous and E.A.B. Gilbert from the University of Guelph shines the spotlight on the cells that drive this superpower: a special type of stem cells called the radial glia located in the spinal cord which is embedded in the tail of the gecko. This paper is hoped to pave the way to the development of treatment methods for spinal cord injuries in humans.
“We knew the gecko’s spinal cord could regenerate, but we didn’t know which cells were playing a key role,” says Vickaryous.
“Humans are notoriously bad at dealing with spinal cord injuries so I’m hoping we can use what we learn from geckos to coax human spinal cord injuries into repairing themselves.”
Re-Growing the Tail at the Cellular Level
Geckos are known for their remarkable talent of letting their tail go as a way of evading predators: the detached organ will continue to wiggle, thereby serving as distraction to the latter. But, the tail also has to grow back; the geckos are the fastest lizard to do this as the regrowth of their tail happens within a month only, hence why they were chosen for the study. When their tail comes off, repair soon starts as the radial glia respond swiftly to the injury, catering for the creation of new tissues, and ultimately a new spinal cord.
This was discovered when the pair of scientists simulated an attack on a gecko: they pinched the latter’s tail so that the animal would drop its tail thinking it was apprehended by a predator. The processes happening at the cellular level before and after the tail was detached were examined.
The Tale Behind the Tail
According to the observations, the radial glia remain relatively inactive until the tail is detached. Then, in the aftermath of the tail loss, these stem cells start synthesising a number of proteins that come together to form the brand new spinal cord.
“But when the tail comes off everything temporarily changes,“ says Vickaryous. “The cells make different proteins and begin proliferating more in response to the injury. Ultimately, they make a brand new spinal cord. Once the injury is healed and the spinal cord is restored, the cells return to a resting state.“
Humans ‘Becoming’ Lizards
Humans respond very differently to spinal cord injuries: we make scar tissue instead of new tissue. This scar tissue is meant to seal the wound at a rapid rate, but this comes at a cost: it prevents regeneration. Vickaryous describes this as a “quick fix” that becomes a problem in the long run.
Perhaps, all we’re missing is the special type of cell, the absence of which restricts our ability to repair our spinal cord, says Vickaryous. The new findings are, therefore, hoped to further research in this domain.
“Geckos are able to regenerate many tissues throughout their bodies, making them ideal models for studying wound healing and tissue re-development. We can learn a lot from them,” explains Vickaryous.