The Elephant's Special Neurons

Photo by David Clode on Unsplash

Every mammal brain contains hordes of pyramidal neurons, a common type of brain cell found in the cerebral cortex. Pyramidal cells take in information from multiple sources then send out a single message to the next neuron in the circuit. These cells possess a thick forest of short dendrites and a single long dendrite — like a tree with its roots pulled out of the ground. But not elephants. Their pyramidal cells look more like long-legged spiders with a few long branches.

Yet, elephant pyramidal neurons have the same total length of dendrites as primate neurons. This implies both cell types can process the same amount of information — so why are they organized in different ways? The long-reaching dendrites might be a consequence of the stretched-out elephant cortex. Compared to humans, elephant brains have more cortical real estate and fewer neurons to accommodate: their brains are three times bigger than humans’, but their cortices contain only two-thirds of the neurons. That means neuronal cell bodies and their dendrites can spread out as the elephant cortex forms.

The different shape also might allow elephants to be elephants. A few long, meandering dendrites on a single cell may combine information from many cells over an extended period of time, while the dense, short dendrites in primate neurons may be best suited for rapid-fire decisions. This more thoughtful cell structure might contribute to elephants’ special qualities, like their creative problem-solving, empathy, complex social structures, and tool use.

About the Author

Calli McMurray

Calli McMurray is the Media & Science Writing Associate at SfN. She graduated from the University of Texas at Austin in 2019 with a Bachelor of Science in Neuroscience.