From this reaction, the scientists took that despite the huge differences between the brains of an octopus and a human, social behavior came naturally built into our DNA.
It doesn't just tell us more about the evolution of serotonergic signalling in the regulation of social behaviours - it's a finding that could help study and develop psychiatric drugs, particularly selective serotonin reuptake inhibitor (SSRI) antidepressants.
Gul Dolen, the assistant professor of neuroscience at the Johns Hopkins University School of Medicine and the lead investigator of the experiment stated: "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". While humans are naturally social creatures, octopuses prefer a solitary existence and rarely socialise, with the exception of mating. MDMA changes how serotonin travels between brain cells, hence the feelings of affection and warmth experienced by those who take the drug. A new study on how an octopus given Ecstasy acts offers clues about how the drug can be used in broader settings.
"This is very similar to how humans react to MDMA; they touch each other frequently", Prof Dolen said.
A summary of the experiments was published in Current Biology.
Scientists have found out what happens when you give an octopus MDMA - nearly the exact same thing as when you give it to a human.
Ecstasy effect on this protein, therefore the authors tried to check on the octopus effect of the drug, enhancing social interaction in humans and some animals. The results of this preliminary experience, so we need a new study before octopi becomes necessary organisms for the study of brain and behavior. The test animals were four male and female octopuses who were administered MDMA.
Zachary Mainen, a neuroscientist at the Champalimaud Centre for the Unknown in Portugal, points out that some research done decades ago showed that giving extra serotonin to lobsters can alter their social behavior.
Dölen received some typical lighthearted responses from people asking about the experiment: "People are like, 'Have you got any pictures of octopuses holding glow sticks?' which I kind of ignore because that wasn't really our objective". The animals absorbed it for a half hour and then were placed in a sort of multi-room chamber.
As for the octopuses - who were hatched in the lab, not caught in the wild - they went through this entire trip just fine. Without the drug, octopuses approached the cage carefully with one tentacle stretched out, but when on MDMA the octopuses behaved much different.
"It's not just quantitatively more time, but qualitative", Dölen said in a statement. She says octopuses have a very different, doughnut-shaped brain.