Octopuses’ brains are similar to humans’

By Mark Waghorn via SWNS

Octopuses' brain are similar to humans'... shedding fresh light on its intelligence.

The enigmatic eight-limbed creature descended from the same primitive worm-like animal, according to a new study.

It has a complex central nervous system - reflecting similar developments that occurred in vertebrates.

"So, this is what connects us to the octopus," said co-author Professor Nikolaus Rajewsky, a biologist at the Max Delbruck Center.

The findings have implications for alien hunters. Octopuses are regarded as the closest thing to how alien life may have evolved.

They are renowned for being clever. They can use tools, carry coconut shells for shelter, stack rocks to protect their dens and use jellyfish tentacles for defence.

In captivity they can learn to solve puzzles, open screw-top jars, and squirt humans they don't like. And they are as smart as your average dog.

Recently they were even filmed throwing rocks and shells at each other.

They belong to a group known as cephalopods - which also include squid and cuttlefish.

Scientists have long wondered how they turned into the brainiest of the invertebrates - rivaling mammals.

Now a study has found octopuses possess a massively expanded repertoire of gene regulators called microRNAs (miRNAs) in their neural tissue.

It reflects similar developments that occurred in vertebrates - including humans.

Rajewsky said the bits of DNA probably play a fundamental role in the development of complex brains.

An analysis of 18 different tissue samples from dead octopuses identified 42 novel miRNA families - mostly in the brain.

The genes were conserved during cephalopod evolution - being of functional benefit to the animals.

"This is the third largest expansion of microRNA families in the animal world, and the largest outside of vertebrates," said lead author Dr. Grygoriy Zolotarov, from the same lab.

"To give you an idea of the scale, oysters, which are also molluscs, have acquired just five new microRNA families since the last ancestors they shared with octopuses - while the octopuses have acquired 90."

Oysters aren't exactly known for their intelligence, added Rajewsky. His fascination with octopuses began years ago, during a visit to the Monterey Bay Aquarium, California.

"I saw this creature sitting on the bottom of the tank and we spent several minutes - so I thought - looking at each other," he said.

"It's not very scientific, but their eyes do exude a sense of intelligence." Octopuses have similarly complex 'camera' eyes to humans.

They are unique among invertebrates with both a central brain and a peripheral nervous system, capable of acting independently.

If an octopus loses a tentacle, the tentacle remains sensitive to touch and can still move.

The reason why octopuses are alone in having developed such complex brain functions may be due to using their arms very purposefully - as tools to open shells, for instance.

They are also very curious and can remember things. They can recognize people and actually like some more than others.

It is believed they even dream, since they change their color and skin structures while sleeping.

"They say if you want to meet an alien, go diving and make friends with an octopus," Rajewsky said.

He is now planning to join forces with other experts to form a European network that will allow greater exchange.

Interest in octopuses is growing worldwide a form of intelligence that developed entirely independently of our own.

But he explained: "If you do tests with them using small snacks as rewards, they soon lose interest. At least, that is what my colleagues tell me."

Added Zolotarov: "Since octopuses aren't typical model organisms, our molecular-biological tools were very limited. So we don’t yet know exactly which types of cell express the new microRNAs."

The team are now planning to apply a revolutionary technique which will make the cells in octopus tissue visible at a molecular level.

The study is published in the journal Science Advances.