For about 25 million years, woodpeckers have been slamming their beaks into trees with incredible force – about 1,200 to 1,400 g’s – to reach bugs that they eat. One g is equal to the force of gravity at the Earth’s surface.
Scientists have been learning a lot more about brain injuries like concussions. Especially in the sport of football, where players often hit each other helmet to helmet at high speed, concussions have become a big deal. They not only cause problems like headache, nausea, dizziness and memory loss at the time, but may lead to memory, emotional and thought difficulties later.
It only takes about 60 to 100 g’s to give a human a concussion, much less than a woodpecker pecks. So scientists decided to examine the woodpecker’s brain to see if there was brain damage in woodpeckers similar to that found in humans who have suffered concussions.
"The basic cells of the brain are neurons, which are the cell bodies, and axons, which are like telephone lines that communicate between the neurons,” explained George Farah, who worked on the study as a graduate student at the Boston University School of Medicine. “The tau protein wraps around the telephone lines – it gives them protection and stability while still letting them remain flexible."
Having some tau proteins is good, but too much can upset communication from one brain cell to another.
So the scientists decided to cut thin slices of preserved woodpecker brains to see if they suffered the same tau increase that humans who have had concussions show. The result?
"We can't say that these woodpeckers definitely sustained brain injuries, but there is extra tau present in the woodpecker brains, which previous research has discovered is indicative of brain injury," Farah said.
If tau buildup was a bad thing, why over the course of 25 million years as woodpeckers evolved wouldn’t nature have figured out some way to protect them from brain injury? Maybe nature did. Maybe the tau in woodpeckers is protective and not bad. Sometimes science answers one question with another one or two.
— Brett French, firstname.lastname@example.org