Octopuses given ecstasy by scientists become more friendly and sociable, study finds

'They tended to hug the cage and put their mouth parts on the cage. This is very similar to how humans react to MDMA; they touch each other frequently,' says scientist

Scientists have found that giving the popular party drug MDMA to octopuses makes the normally reclusive creatures highly sociable.

When humans take the illegal substance – commonly known as ecstasy – they experience euphoria and closeness to others, effects that have made it popular among revellers at nightclubs and festivals.

Even though they are separated from humans by 500 million years of evolution, the new research suggests that octopuses experience very similar effects.

The unusual study was conducted by scientists in an attempt to understand the ancient brain mechanisms that control social behaviour in animals.

Octopuses are widely known to be intelligent animals, capable of outwitting prey and solving complex puzzles, but their brains are totally alien when compared to our own.

“The brains of octopuses are more similar to those of snails than humans, but our studies add to evidence that they can exhibit some of the same behaviours that we can,” says Dr Gul Dolen, a neuroscientist at the Johns Hopkins University School of Medicine who led the experiments.

Dr Dolen’s genetic analysis of the California two-spot octopus, an animal widely used in scientific laboratories, revealed that its brain had the molecular components required to sense MDMA.

In particular, these marine invertebrates share the same genes that control how brain cells bind with serotonin – a chemical that controls mood.

The question that remained was whether these creatures, which normally live a solitary existence, would show any distinctive behaviour changes associated with an ecstasy user.

To find out, they placed eight subjects in baths containing MDMA for 10 minutes before placing them in specialised chambers in which they had the choice of interacting with plastic action figures or other octopuses in cages.

Subjects under the influence of the drug spent more time with other octopuses, and during this time they engaged in a lot of close physical contact. The scientists noted that this contact did not appear aggressive in nature.

“They tended to hug the cage and put their mouth parts on the cage,” said Dr Dolen.

“This is very similar to how humans react to MDMA; they touch each other frequently.”

While octopuses are known to be more sociable when they are mating, suggesting they can suppress their unsociable nature, for the most part the experiments confirmed that when octopuses were not given MDMA they preferred to stay away from their fellows.

The results of this study, published in the scientific journal Current Biology, suggest there are deep evolutionary connections between human behaviour and that of octopuses.

“What our studies suggest is that certain brain chemicals, or neurotransmitters, that send signals between neurons required for these social behaviours are evolutionarily conserved,” explained Dr Dolen.

Nevertheless, the researchers said the paper was only the first step into this very new area of research, and said the results must be confirmed by further experiments before the octopus becomes a new laboratory model for the human brain.