The trunk of an elephant contains 40,000 muscles and weighs more than a Burmese python. The appendage is powerful enough to uproot a tree while being delicate enough to suck up fragile tortilla chips.
But how does an elephant’s brain aid in these dexterous feats? According to Michael Brecht, a neurologist at Humboldt University of Berlin, this has proved challenging to research. The elephant’s brain, which weighs more than ten pounds, deteriorate fast after death and is difficult to keep.
Dr. Brecht and his colleagues were lucky to acquire access to a collection of elephant brains from animals who died naturally or were killed for health reasons and ended up frozen or in a fixative material at Berlin’s Leibniz Institute for Zoo and Wildlife Research.
Dr. Brecht and his colleagues revealed Wednesday in the journal Science Advances that elephants possessed more face neurons than any other terrestrial animal, which may contribute to trunk dexterity and other morphological talents. The research also assisted in identifying significant variations in the neurological wirings of African savanna elephants and Asian elephants.
The researchers focused on the facial nucleus, a bundle of neurons localised in the brainstem and connected to facial nerves, using the brains of four Asian elephants and four African savanna elephants. These neurons act as the control centre for face muscles in animals. When you wrinkle your nose, purse your lips, or lift your brows, they take authority. They also assist elephants in using their trunks.
The face nucleus was separated into areas of neurons that regulated the elephant’s ears, mouth, and trunk. African elephants have 63,000 face neurons, while Asian elephants had 54,000. Dolphins have over 90,000 facial neurons in their sensitive snouts, making them the only animals with more.
While his team anticipated both African savanna and Asian elephants to have huge reserves of facial neurons, Dr. Brecht noted a significant difference between the two species.
While the animals appear identical, they have significant facial variances. African elephants have substantially bigger ears that fan out while charging. The researchers discovered a biological link: African elephants expend almost 12,000 face neurons to managing only their ears. This amount of neurons not only dwarfs the number of neurons controlling Asian elephant ears, but it is about 3,000 more neurons than are required to function the complete human face.
Another significant distinction is how each elephant uses its trunk, which takes about half of the elephant’s total face neurons to function. African elephants pinch items with two fingerlike extensions on the ends of their trunks, similar to how chopsticks are used. Asian elephants have a single fingerlike protrusion on their trunks and grab items by wrapping their trunks around them. The researchers identified two brain areas in African elephants that were most likely associated with precise finger control at the ends of their trunks; these regions were less defined in Asian elephants.
While delineating the responsibilities of various areas of the elephant’s facial nucleus’s wide network is useful, Suzana Herculano-Houzel, a neuroscientist at Vanderbilt University who was not involved in the current study, believes the amount of neurons is predictable for such a massive species.
She said that other regions of the elephant brain are likewise amazing. Dr. Herculano-research Houzel’s has showed that the elephant’s cerebellum, the brain area that regulates motor activities, contains 12 times the number of neurons predicted for an animal of its size.
While the face neurons are hardly out of this world, Dr. Brecht feels that a greater knowledge of these structures in elephants might give insights into other big animals, including humans.
