What an Elephant’s Brain Reveals About Its Trunk

Elephant trunks are incredibly strong but very dexterous—they can lift more than 700 pounds, yet also pick up a single blade of grass. The massive mammals use these long noses to eat, drink, smell, trumpet and breathe. 

“It’s like a muscular multitool,” Andrew Schulz, a mechanical engineer at the Georgia Institute of Technology, told the New York Times’ Richard Sima last year.

Now, researchers have studied the elephant facial motor nucleus—the part of the brain responsible for controlling muscles in the face, including the trunk—in detail for the first time, per a statement. The findings, published last week in Science Advances, reveal that elephants have tens of thousands of facial neurons—more than any other land mammal, which may help explain their trunks’ remarkable skills.

“As you might have expected because of their size and because of elephants’ very special facial abilities, there are six times more neurons that innervate the musculature of the elephant face compared to humans,” co-author Michael Brecht, a researcher at Humboldt University of Berlin, tells the Wall Street Journal’s Dominique Mosbergen. 

The team examined four Asian elephant (Elephas maximus) brains and four African savanna elephant (Loxodonta africana) brains, and they found that about half of elephants’ facial neurons are dedicated to the trunk. And the brain cells that controlled the tip of the trunk’s movement are larger than those associated with the parts of the trunk that are closer to the face.

But between the two elephant species, the researchers found some major neural differences. For one, they used their trunks differently, a contrast reflected in their brains. An Asian elephant has one “finger” at the trunk’s tip, so it will pick up an object by wrapping the entire trunk around it. African savanna elephants, on the other hand, have two of these fingers, which they use to hold items.

“This kind of pincer grip requires much dexterity with the trunk tip,” co-author Thomas Hildebrandt from the Leibniz Institute for Zoo and Wildlife Research says in the statement. “Not surprisingly, we see in the brains of African elephants prominent neuron clusters for the control of the fingertips.”

The ears, too, differed between the species. African elephants have roughly 63,000 facial neurons, of which about 12,000 are used to control their ears. The Asian species, meanwhile, has some 54,000 facial neurons, with about 7,500 of them used for ear movement. This may partially be because of the animals’ physical differences: Asian elephants have smaller, rounder ears than their African relatives.

“It’s a beautiful example of how species’ diversity in brain structure maps to a body’s specialized anatomy,” Chet Sherwood, a biological anthropologist at George Washington University who was not involved with the study, tells the Wall Street Journal. 

Brecht tells the New York Times’ Jack Tamisiea that research into elephant neurons could help uncover clues about the brains of other large animals, including humans.  

“Although we’re not as big as elephants, we’re still quite big,” he tells the publication, adding that “you probably would not see [these patterns] in a mouse.”

Margaret Osborne | | READ MORE

Margaret Osborne is a freelance journalist based in the southwestern U.S. Her work has appeared in the Sag Harbor Express and has aired on WSHU Public Radio.