The trunk of an elephant has 40,000 muscles and is heavier than a Burmese python. The appendage is both powerful enough to uproot a tree and delicate enough to suck up fragile tortilla chips.
However, how does the elephant’s brain contribute to these feats of dexterity? According to Michael Brecht, a neurologist at the Humboldt University of Berlin, this has proved challenging to examine. The elephant’s brain, which weighs over 10 pounds, deteriorate rapidly after death and is difficult to keep.
Dr. Brecht and his colleagues were lucky enough to acquire access to elephant brains from animals who died of natural causes or were killed for health reasons and ended up frozen or in a fixative at the Leibniz Institute of Zoo and Wildlife Research in Berlin.
Dr. Brecht and his colleagues found in a research published Wednesday in the journal Science Advances showed elephants possessed more face neurons than any other terrestrial animal, which may contribute to trunk dexterity and other morphological talents. The investigation also contributed to the identification of significant variations between the neurological wiring of African savanna elephants and Asian elephants.
Using the brains of four Asian elephants and four African savanna elephants, the researchers identified the facial nucleus, a concentration of neurons in the brainstem connected to facial nerves. These neurons act as the face muscle control centre in animals. When you wrinkle your nose, purse your lips, or raise your eyebrows, they are in charge. They also assist elephants in using their trunks.
The scientists subdivided the face nucleus into neuronal areas that regulated the elephant’s ears, mouth, and trunk. African elephants have 63,000 facial neurons, but their Asian relatives possessed just 54,000. The only animals with more face neurons are dolphins, which pack over 90,000 into their delicate snouts.
Despite the fact that Dr. Brecht’s team predicted both African savanna and Asian elephants to have many facial neurons, the divergence between the two species is notable.
While the animals seem identical, they have distinct facial features. African elephants have much bigger ears, which they spread out while charging. The researchers discovered a biological correlation: African elephants dedicate around 12,000 face neurons to ear control alone. This is approximately 3,000 more neurons than are required to run the complete human face, and dwarfs the number of neurons controlling the ears of Asian elephants.
Another important distinction is how each elephant uses its trunk, which takes approximately half of its face neurons to function. African elephants use two finger-like extensions on the ends of their trunks to pinch items, similar to how chopsticks are used. Elephants in Asia have just a single fingerlike extension and hold items by wrapping their trunks around them. The researchers identified two brain areas in African elephants that are likely associated with fine finger control at the trunk ends; these regions were less well-defined in Asian elephants.
Suzana Herculano-Houzel, a neuroscientist at Vanderbilt University who was not involved in the new study, believes that the number of neurons in the elephant’s facial nucleus is unsurprising for such a large mammal, despite the importance of defining the functions of the network’s various components.
She said that other regions of the elephant brain are likewise amazing. Dr. Herculano-study Houzel’s demonstrates that the cerebellum of the elephant, which governs motor activities, has twelve times as many neurons as predicted for an animal of its size. She said, “The elephant’s cerebellum is astronomical in comparison to all other animals.”
Dr. Brecht thinks that a greater knowledge of these structures in elephants might provide light on other big animals, such as humans, despite the fact that elephant face neurons may not be out of this world.
“Although we’re not as large as elephants, we’re still fairly large,” he said, adding that these are patterns “you definitely wouldn’t see in a mouse.”