The octopus is an amazing creature – and not just because of its eight organs, three hearts, blue blood, ink squirting, camouflage ability and the compelling fact that it dies after breeding.
A study by researchers in Brazil published Thursday shows that this animal, already considered the most agile invertebrate, is experiencing two other major sleep states which are eerily similar to those in humans, and could even dream.
The findings, the researchers said, provide new evidence that the octopus has a complex and solemn neurobiology that underpins an equally solemn behavioral repertoire, while at the same time offer a broader view of sleep evolution, a vital biological function.
Octopuses were previously known to experience sleep deprivation and color changes while sliding. In the new study, the researchers looked at a species called Octopus insularis in a laboratory setting. They found that these color changes are associated with two distinct sleep states: “quiet sleep” and “active sleep.”
During “quiet sleep,” the octopus remains, with pale skin and eye pupils attached to a slit. Through “active sleep,” it dynamically changes the color and texture of its skin and moves both eyes while contracting its suckers and body, with muscular cigarettes.
A repetitive circle was observed during sleep. “Silent sleep” usually lasted about seven minutes. The “active sleep” then lasted less than a minute.
This circle appears to be synonymous, the researchers said, with the “rapid eye movement,” or REM, and “non-rapid eye movement,” or non-REM, movement states that experienced sleep states. humans, as well as other mammals, birds and reptiles.
Vibrant dreaming occurs during REM sleep, as a person’s eyes move rapidly, breathing becomes irregular, heart rate increases and muscles become paralyzed to prevent constipation. the action of dreams. Non-REM sleep reflects deeper sleep and less dreaminess.
The study’s lead author Sylvia Medeiros said the findings show that octopuses may be dreaming, or experiencing something similar.
“If octopuses are indeed dreaming, they are unlikely to experience complex symbolic plots as we do,” said Medeiros, a doctoral student in neuro-science at the Brain Institute of the Federal University of Rio Grande do Norte.
“Active sleep in the octopus has a short duration, usually from a few seconds to one minute. If any dream is going on in this state, it should be more like small video clips, or even GIFs, ”said Medeiros.
Scientists are seeking more understanding of the origin and evolution of sleep.
Given that the last common ancestor of vertebrates, including humans, and cephalopods, including octopuses, lived more than half a billion years ago, it seems that the similar sleep patterns did not occur. established before their evolutionary separation, the researchers said.
That would mean, they said, that this similar sleep pattern arose independently in both groups, known as “convergent evolution.”
“The study of sleep and dreaming in the octopus provides an insight into the psychological and neurobiological comparison with spinal cord, as the octopus has a number of cognitive features that can only be seen in some skeletal species but by architecture. a very different brain, ”said study co-author Sidarta Ribeiro, founder of the Brain Institute.
Ribeiro noted that previous studies have shown that octopuses have unique learning abilities, with the most centralized nervous system of any invertebrates, including spatial and social learning, as well as problem-solving abilities.
“Understanding how organisms as different from humans and octopuses can share basic features such as the sleep cycle opens up new avenues for studying animal knowledge and understanding the common principles that have shaped brain design in these groups of highly intelligent animals, ”Medeiros said. Reuters