The nine-armed octopus and the oddities of the cephalopod nervous system
With their quick-change camouflage and high level of intelligence, itβs not surprising that the public and scientific experts alike are fascinated by octopuses. Their abilities to recognize faces, solve puzzles, and learn behaviors from other octopuses make these animals a captivating study.
To perform these processes and others, like crawling or exploring, octopuses rely on their complex nervous system, one that has become a focus for neuroscientists. With about 500 million neuronsβaround the same number as dogsβoctopusesβ nervous systems are the most complex of any invertebrate. But, unlike vertebrate organisms, the octopusβs nervous system is also decentralized, with around 350 million neurons, or 66 percent of it, located in its eight arms.
βThis means each arm is capable of independently processing sensory input, initiating movement, and even executing complex behaviorsβwithout direct instructions from the brain,β explains Galit Pelled, a professor of Mechanical Engineering, Radiology, and Neuroscience at Michigan State University who studies octopus neuroscience. βIn essence, the arms have their own βmini-brains.ββ
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