Octopuses get very friendly when they're on MDMA, study reveals

21 September 2018, 10:23 | Updated: 21 September 2018, 16:27

Scientists have found out what happens when you give an octopus MDMA - almost the exact same thing as when you give it to a human.

Octopuses are mostly solitary creatures who rarely spend time with each other, preferring to keep their own company other than during mating.

But as in humans, when the octopuses receive a dose of MDMA, also known as the party drug ecstasy, they begin to become very social indeed.

Neuroscientists from John Hopkins University in the US conducted the study and published it in the journal Current Biology, and say that it reveals something profound about how our brains work.

Octopuses' social response is curious because humans and octopuses have more than 500 million years of divergent evolution, making us very different creatures indeed.

Among the many differences between us are the different anatomical patterns of our brains, but there is growing evidence we could share some very ancient neurotransmitters.

This could explain why MDMA has a similar effect on both species.

Creatures across the whole of the animal kingdom exhibit social behaviours, from invertebrates including ants and bees, through to vertebrates like fish and primates.

An ancient molecule called serotonin is believed to be an important neurotransmitter driving particular kinds of social behaviours. It's present in all of these species, and MDMA causes high levels of serotonin to flood the brain.

Dr Gul Dolen, the lead researcher in the study, said she and her colleagues had to work hard to figure out what the appropriate dose was for an octopus.

They administered the drug by adding it to a tub of water in which they bathed an octopus for 10 minutes.

"I have to admit that it was totally trial and error. Honestly, I just didn't think this was going to work, so we started out at super high doses," she told ABC.

"But the animals went through this hyper-vigilance where they were perched at the top of the tank like a hawk trying to watch a mouse or something."

The team then rapidly pulled back the dose, and the results were very similar to humans.

Instead of reaching out to touch objects with one arm, the octopuses would reach out with six to play with a flowerpot and appeared more relaxed in their posture.

One octopus was doing back flips, according to Dr Dolen, who said that some of the behaviours were so strange the research team couldn't quantify them.

The research in Dr Dolen's lab is focusing the neural causes and mechanisms behind particular kinds of behaviour, and the links to autism and schizophrenia.

Dr Dolen said further research could reveal how brain processes behind those disorders function.