Picture from Wikimedia Commons

Can you make an Octopus dance? A recent study published by Biology Current has concluded that you can. The study suggests that the impacts of MDMA on the social behavior of the California Two-Spot Octopus and humans are strikingly similar. MDMA, otherwise known as ecstasy or ‘Molly’, has, as of late, become a substance of increasing interest to geneticists.

So, what is all the hype about? Why give an octopus MDMA? Octopuses have a strong reputation for being extremely antisocial and are known for their aggressive behavior. So much so that if they are forced into close proximity, one octopus is likely to eat the other.

In rare instances they have been known to cooperate or let their guard down enough to engage in sexual behavior. But, even at this time if a male octopus stays around at all after the deed is done there is a good chance that the female will attack him.

Aside from their exceptionally antisocial behavior, Octopuses have a keen sense of environmental awareness and are very intelligent creatures. They have been known to successfully complete complex water mazes, and are much more aware of their surroundings than your average goldfish. In the words of Stefan Linquist of the University of Guelph in Ontario, “when you work with fish, they have no idea they are in a tank, somewhere unnatural. With octopuses it is totally different. They know that they are inside this special place, and you are outside it. All their behaviors are affected by their awareness of captivity.”

“Octopuses have been known to observe and make predictions about their surroundings to such a high degree that some have learned to squirt water outside their tanks at the light bulbs to turn off the lights…”

Peering outside their tanks, Octopuses have been known to observe and make predictions about their surroundings to such a high degree that some have learned to squirt water outside their tanks at the light bulbs to turn off the lights, which can become quite expensive for their caretakers!

Octopuses do have highly developed brains. Located in their throat and throughout their arms, the octopus’ nervous system is distributed throughout its body. Even more interesting is that the neurons stretching down their arms seem to have a mind of their own! They are able to respond to outside stimuli without direction from their “main brain”.

So, again, why give an intelligent, aggressive and antisocial creature MDMA? The answer lies deep in the folds of evolution. Looking through the passage of time you will find that there have been hundreds of millions of years of evolution between the octopus and the human, with our closest common ancestor being close to the aquatic worm. But, strangely enough, certain genetic characteristics have been preserved through that time.

“The gene that helps produce this neurotransmitter (SLC6A4) surprisingly, also appears in the Octopus’ genetic makeup.”

In humans, the neurotransmitter responsible for feelings of happiness, serotonin, is released in extremely large quantities after ingesting MDMA. This fact explains part of the drug’s appeal among ravers.  A lack of serotonin plays a large role in anxiety disorders and depression in humans. The gene that helps produce this neurotransmitter (SLC6A4) surprisingly, also appears in the Octopus’ genetic makeup. It is because of this fact that Gül Dölen, a neuroscientist at the Johns Hopkins University School of Medicine and colleagues were interested in the behavioral impacts MDMA would have on the octopus.

As part of this study, the researchers placed the octopuses in a bath containing MDMA for 10 minutes and then soaked them in a saline solution for 20 minutes. This is because it takes about 30-60 minutes for the full effects of MDMA to present themselves. After this waiting period, the octopuses were allowed them to freely roam within a three-chambered tank. The far-left chamber contained a novel item (a colored pot with an action figure inside it), the middle chamber was empty and the far-right chamber contained another octopus who was also given MDMA. The octopuses were observed for about an hour. What Gül Dölen and colleagues found was that the octopuses spent significantly more time in the social chamber while on MDMA as compared to their baseline findings.

“What Gül Dölen and colleagues found was that the octopuses spent significantly more time in the social chamber while on MDMA as compared to their baseline findings.”

The octopus’s social behavior while on MDMA mirrored that of a human. They became exceptionally friendly toward one another and according to Dölen, “some were being very playful, doing water acrobatics or spent time fondling the airstone [aquarium bubbler]…[others were] basically hugging the [cage] and exposing parts of their body that they don’t normally expose to another octopus”.

This experiment is interesting as it shows that even after 500 million years of genetic separation, we still share an important part of our neurochemistry with octopuses. Gül Dölen and colleagues have shown important proof-of-concept data that much of what we consider human biology extends far beyond our own species. Future research is likely to explore this link further, deepening our understanding of  the serotonergic system in humans and other species alike.