Like humans, octopuses want more hugs when they are on the ecstasy | Science

Humans and octopuses are separated by 500 million years of evolution, but seem to share an unusual thing in common: both are affected by ecstasy, according to a new study.

In humans, ecstasy, also known as 3,4-methylenedioxymethamphetamine (MDMA), binds to a protein found in neurons. The genetic code of this protein is stored in a gene called SLC6A4. When MDMA docks with this protein, our brain cells start pumping huge amounts of serotonin, the chemical responsible for the warm and friendly feelings of ecstasy. Octopus genomes also contain a copy of SLC6A4, the researchers wondered if the drug would have a similar effect on them.

The team placed four two-point octopus in California (Octopus bimaculoids, pictured) in a tank containing a liquefied liquid extract version, which the animals absorbed through their gills. Then the scientists placed the octopus individually in a three-chamber water tank for 30 minutes: a vacuum; one with a plastic figurine, an object that piques the curiosity of the octopus; and one with a female or male octopus raised in the laboratory under a cage.

Octopuses are usually antisocial outside the mating season, but when they are under the influence, all four spend several more minutes with the other octopus than in the solitary chamber or the one with the interesting object, reports the team today. Current biology They also tended to hug and put their mouthparts on the cage in an exploratory and non-aggressive manner, much like their behavior during the mating season.

The results suggest that, despite the huge evolutionary gap that separates us, humans and octopuses seem to have similar brain chemistry guiding their social behaviors. However, with such a small sample size, scientists warn that results need to be confirmed in other experiments before octopuses are used to study the functioning of the human brain. But for now, they seem to have discovered a sure way to liven up an octopus party.