Scientists have given ecstasy to octopuses to investigate our shared past of social behavior – Science News

American scientists gave ecstasy to octopus – for good reason.

They discovered fascinating ideas about how social behavior is coded and traced its biological roots back to a common ancestor of our time, which lived about 500 million years ago.

The work, led by neuroscientist Gul Dolen of Johns Hopkins University, was published today in Current Biology.

Since brains are soft and soft, they tend to be eaten or rotten long before they can be fossilized and preserved.

This means that we do not really have physical evidence of the evolution of our brain over time.

Researchers need to think sideways – and suggest ideas like giving 3,4-methylenedioxy-methamphetamine or MDMA, commonly known as ecstasy, to octopus.

Why give an ecstasy to an octopus?

Ecstasy acts in part by flooding the brain with a chemical called serotonin.

Among its effects, it makes people more sociable than normal.

But octopus prefer mostly a solitary life – they are not known to frequent outside mating.

The question was: if serotonin codes for social behavior in people, would it have the same effect on octopus?

Or to put it another way, if you give ecstasy to an octopus, would you tell her friends that she loved them at three in the morning with eight lollipops in her tentacles?

And if we better understand how social behavior is coded, can it help us solve problems when things go wrong in people?

How much ecstasy do you give an octopus?

If you have never given ecstasy to an octopus, the first hurdle is to determine the proper dose and how to administer it.

Octopuses breathe by throwing water on their gills like a fish.

So, Dr. Dolen and his colleagues added ecstasy to a cup of water and gave a 10 minute bath to an octopus species, Octopus bimaculoides.

"I have to admit that it was totally a mistake, honestly, I did not think it was going to work, so we started at very high doses," she said.

Surprised by the sensitivity of the octopus to the drug, the researchers reduced the dose.

"When we gave them the dose you gave to a human, but adjusted for weight, they started to act as you can imagine," said Dr. Dolen.

When properly dosed, it was the time of the experiment.

The configuration consisted of a tank with three chambers connected by small openings through which an octopus test located in the central chamber could move.

An object such as a flower pot was placed in the left chamber and another octopus trapped to the right.

Without ecstasy, trial octopuses spent much more time in the room with the object. But with ecstasy, they became more social, preferring the room with the other octopus.

And the nature of the interactions between the octopus has also changed.

Before a dose of ecstasy, social interactions were "limited, usually to an extended arm," the scientists wrote.

"After the MDMA treatment, the social interactions were characterized by a large ventral contact, which seemed to be exploratory rather than aggressive," they said.

The researchers also developed a system to quantify the behavioral changes of the octopus after receiving ecstasy.

Unfortunately, some behavioral changes did not fall within the scope of the classification.

"They were really interested in touching each other – instead of reaching out with one arm, they would reach out to six to manipulate the flowerpot, and they seemed more relaxed in their posture," said Dr. Dolen.

So what does it tell us to bring up the octopus?

From these first results and a sample of four octopuses, researchers believe that serotonin codes their social behavior.

Although the octopuses are usually solitary animals, Zoe Doubleday of the University of Adelaide, who did not participate in the study, said they adapt quickly to different environments.

"Even when you work with octopuses in tanks, they all have very different personalities," Dr. Doubleday said.

A dozen octopus were found last year in an "octopus" town, nicknamed "Octlantis", in the bay of Jervis, on the east coast of Australia.

Dr. Doubleday said that octopuses may be more social than we think, but they need some environmental triggers to display this behavior.

Although further research is probably needed to conclude that serotonin produces a social response, she stated that the effects of alcohol on octopus were unclear.

Dr. Dolen and his team also explored the octopus genome for clues to social behavior.

In humans, the SLC6A4 gene encodes a protein that carries serotonin. This protein is targeted by ecstasy, which increases the release of serotonin in the brain and blocks its reuptake.

And it turns out that octopuses have something similar. Dr. Dolen and his team have identified an orthologue SLC6A4 – a gene that has retained the same function in octopus.

They said that they believed that social behavior was present in our common ancestor more than 500 million years ago but that it was "extinct" in octopuses.

There is currently a renaissance in research on the potential benefits of psychotropic drugs such as ecstasy, LSD and psilocybin, the compound found in hallucinogenic mushrooms.

Ecstasy has been shown to help treat post-traumatic stress disorder and psilocybin in the treatment of depression and anxiety disorders, for example.

Dr. Dolen's lab is studying how the brain encodes social behavior and its connection to autism and schizophrenia.

If MDMA activates social behavior in octopus, further research could provide insight into how these processes work, she said.