Octopuses on Ecstasy: MDMA Makes Intelligent Creatures More Social

Scientists have been exploring the neurochemical basis of social behavior, and a recent study has yielded surprising results: administering MDMA, commonly known as ecstasy, to octopuses dramatically increases their sociability. The research, initially published in the journal Current Biology, offers a unique window into the evolutionary roots of social interaction, even across vastly different species.

Octopuses are generally solitary creatures, often exhibiting aggressive behavior towards one another except during mating. Researchers typically house them separately to prevent injury or predation. This inherent asociality makes the observed changes following MDMA administration particularly striking.

The study, led by Gül Dölen, a neuroscientist at Johns Hopkins University School of Medicine, involved California two-spot octopuses. The experimental setup consisted of three connected water chambers. In one chamber, an octopus was confined within a mesh container, preventing physical harm but allowing for interaction. A second chamber held a plastic toy, serving as a control. Four additional octopuses were then introduced to the tank to observe their behavior towards both the contained octopus and the inanimate object.

Researchers meticulously measured the amount of time each octopus spent near the container with the other octopus versus the chamber with the toy. Before receiving MDMA, the octopuses largely avoided the container, preferring to remain in the area opposite the other animal – a predictable outcome given their natural tendencies. However, after being exposed to a liquefied form of MDMA absorbed through their gills, their behavior underwent a significant transformation.

The octopuses exposed to the drug spent considerably more time in close proximity to the container holding the other octopus. Notably, they began to exhibit behaviors reminiscent of physical affection, “hugging” the cage and extending their mouthparts to touch it. As Dr. Dölen explained, “They tended to hug the cage and put their mouth parts on the cage. Here’s very similar to how humans react. they touch each other frequently.” This mirroring of human responses to MDMA – increased sociability and physical touch – was unexpected, given the evolutionary distance between the two species.

MDMA exerts its effects in humans by increasing the levels of serotonin in the brain, a neurotransmitter associated with feelings of well-being and social connection. The researchers hypothesized that a similar mechanism might be at play in octopuses. The serotonin-binding transporter, a protein involved in serotonin regulation, is also the target of MDMA in the brain. The study suggests that this pathway may be evolutionarily conserved, meaning it has been maintained across a wide range of species due to its importance in regulating social behaviors.

Judit Pungor, a neuroscientist at the University of Oregon who was not involved in the study, expressed her surprise at the findings, stating, “I was absolutely shocked that it had this effect.” The fact that a drug known for its impact on human social behavior could elicit a similar response in an invertebrate with a vastly different brain structure is a compelling indication of the deep evolutionary roots of sociality.

The octopus brain is remarkably different from that of humans. Their closest relatives are snails and slugs, and their brain structures have evolved along a completely separate trajectory. This makes the observed similarities in response to MDMA even more intriguing. The research suggests that the underlying neurochemical mechanisms driving social behavior may be more fundamental than previously thought.

The implications of this research extend beyond simply understanding octopus behavior. Dr. Dölen believes that studying the effects of MDMA on octopuses could provide valuable insights into the neurochemical basis of social behaviors across a broader range of species, including humans. “As human beings, we like to know where we came from,” she said. “MDMA is an amazing tool for studying social behaviors across multiple species.”

the study could potentially improve our understanding of psychiatric drug therapies. By studying the effects of drugs on a relatively simple nervous system like that of an octopus, researchers may be able to better predict and understand their effects on more complex brains. Dr. Dölen emphasized the importance of focusing on the molecular level, stating, “This reiterates the importance of understanding function [at] the level of molecules. Focusing on brain regions does not give us the whole story.”

While the study provides compelling evidence of a link between serotonin and social behavior in octopuses, it’s important to note that this is a preliminary finding. Further research is needed to fully elucidate the mechanisms involved and to determine whether the same neurochemical pathways are responsible for social behavior in other species. However, this study offers a fascinating glimpse into the evolutionary history of social interaction and highlights the potential for using diverse animal models to unravel the complexities of the brain.