Body + Brain

06
Jan

Can Bighorn Sheep Help Us Prevent Concussions?

What can bighorn sheep teach us about football?

Certainly nothing related to passing or kicking, but the large ungulate can help us understand why humans are so prone to brain injuries. Bighorn sheep, along with woodpeckers and a handful of other animals, have brains that are well-protected against impacts. They bash their heads all day yet experience little apparent brain damage.

bighorn-sheep
Some animals’ brains are well-protected against concussions due to a phenomenon called the "bubble wrap effect."

That’s not the case with humans. As NOVA Next contributor Phil McKenna reported in October, some scientists have reported finding chronic traumatic encephalopathy in living people—a first for a disease that typically requires a brain autopsy to diagnose—including a handful of retired N.F.L. players. CTE results from multiple concussions or sub-concussive blows over the course of a person’s life. For athletes in certain contact sports, head hits are all too common, and the jarring impacts cause the human brain jostle around the skull, which is slightly larger than the brain itself. So with every tackle and fall, a football player runs the risk of bumping his brain. To minimize the damage from this “brain slosh,” policymakers and scientists have been working to increase the quality sports equipment and set up preventative measures, such as better concussion testing and CTE detection services.

They’re also looking for solutions in some unlikely places. Here’s Gregory D. Myer, director of research in sports medicine at Cincinnati Children’s Hospital Medical Center, writing for The New York Times:

Bighorn sheep ritually ram their heads into each other and woodpeckers slam their heads against trees thousands of times a day with neither species’ sustaining concussions or even much of a headache, as far as we know. Meanwhile, much lesser forces result in a concussion, or worse, in humans. Our analysis suggests that both woodpeckers’ and bighorns’ brains are naturally protected with mechanisms that slow the return of blood from the head to the body — increasing blood volume that fills their brains’ vascular tree, creating the Bubble Wrap effect.

We have observed that the woodpecker uses muscles to do this, while the sheep has hollow pneumatic horn cores attached to its respiratory system that allow it to re-breathe its air and thus increase carbon dioxide in its bloodstream, expanding its intracranial vascular tree and enhancing the Bubble Wrap effect.

That same bubble wrap effect also appears to lower the incidence of concussions among football players at high altitudes, according to a study by researchers at the Cincinnati Children’s Hospital Medical Center. They hypothesized that higher altitudes increased the volume of blood coursing through the brains arteries and veins, mimicking this bubble wrap effect seen in bighorn sheep.

Short of playing every football game in the mountains, researchers still don’t know exactly how this research will transfer to the real world. But in the meantime, changes to rules of the game for contact sports—especially for youth sports, as children’s brains are even more susceptible—could help keep us safe while still enjoying athletic competitions.