Octopus studies have been very popular to study from a science perspective. So let's dive into some of the many studies out there.

Recently scientists have been studying how complex brain functions work by looking at octopuses. It’s one thing to study humans, but in order to get an unbiased perspective of brain function worldwide, you need to also study animals. Because octopuses are capable of high levels of problem solving, and other cognitive behaviors, scientists are using octopuses as a model organism for this particular task.

Scientists often study animal brains. Fruit flies and zebrafish have also been a part of these studies. As they are easy to raise in a lab. However, this can limit our understanding of the experiences of these species if they are raised in a lab. For example, you’d probably have less life experience and personality if you were confined in a box all day.

But after sequencing octopus genomes in 2015, scientists realized they might have to take a look at certain species outside of a lab. When a genome of a creature is sequenced , it gives a better insight into specific genes that make the brain of a creature work. As well as how evolution helped calculate genes between species.

After sequencing the genes of an animal, scientists can then activate and create inactive cells. By don’t this they can see how neural pathways are activated in the brain of an animal, and simulate responses in a controlled environment. This also lets scientists study brain activity in real time.

Another set of brain studies that are happening are how octopuses react to different drugs. In 2018 , Dölen and co-author Eric Edsinger ( Johns Hopkins University School of Medicine) dosed a few octopuses up with MDMA and found out their neural responses changed their behavior while they were on the drug. They found that their sober octopuses would continue to be antisocial, and avoid each other. The octopuses on drugs however, acted similar to how humans experienced the drug.

The octopuses started getting frisky with each other, relaxed and became curious about what the other octopuses were doing. This sounds on the surface like a huge waste of money. Surface level, a bunch of horny octopuses floating around a lab doesn’t seem like a good idea. However, there was a purpose to this study.

MDMA (ecstasy) can be considered an empathogen. As it reduces inhibitions, social anxiety , hostility, anger, and overall fear of social interaction. So it is seen as a great drug to give to participants in controlled studies. As it can help scientists understand positive interactions between species, ease pain, and overall tension in a subject. It can also help unlock behavior that subjects might not normally display in public.

By giving octopuses this drug and watching their responses, scientists were able to conclude that these animals process serotonin the same way we do, and their serotonin transporters are the same ones that bind MDMA to vertebrates. This just means that when it comes to social behavior in animals, it could be caused less by activity in certain regions of the brain and more to do with how serotonin bonds to other molecular mechanisms in the brain.

So you’re probably wondering if it's ethical to keep octopuses in a lab setting. Or how scientists look, or raise these creatures ethically. Well, this is another reason why gene sequencing is so important. Usually , it is extremely hard to breed octopuses in a lab or a tank. So often grabbing a few from the wild and experimenting on them has happened in the past. Doing this can raise risks and stress levels for the animal. However, Marine Biological Laboratory is one place that is trying to ethically breed octopuses for science. Starting in 2016, they started to attempt gene sequencing of the Octopus chierchiae for their cephalopod breeding program. They concluded it’s small size would make it an ideal model organism to study, and unlike larger octopuses, they are able to breed them in a lab setting.

Let’s dive into the mechanics that are being created from studying octopus biology.

Starting with their skin, scientists have now been able to produce sheets with temperature sensitive dye to mimic cephalopod camouflage. They were able to create these camouflage sheets by studying how these creature’s skin works. As well as how they change color without any external input.

Cephalopod skins use a three-layered system to change color. The first layer of their skin contains a pigment in their chromatophores(organs). These organs change color in response to the signals sent out by the muscles underneath. The second layer of the skin contains light reflecting cells. These cells can turn themselves on and off within seconds. The lowest layer of cells is a layer of white cells. These cells create a bright backdrop to control the number of patterns going over the skin. However, octopus skin also contains photosensitive cells that detect light and patterns without relying on the octopus’s brain to process them first.

The scientists took this information, and then created a small multilayer grid that included temperature sensitive dye. This dye was designed to mimic the chromatophores and diodes in the octopus’s skin and muscles. Then they also added a layer of silver and light sensing diodes to mimic photosensitive cells.

The way their “skin” works is that the diodes can sense the incoming light, then they trigger the muscle-mocking diodes to heat up the dye. Then the dye turns colorless and reveals the white layer of pigment below. So their system currently can only be used for black and white color systems, but they are also working on a full color version.

Octopus vision is also a topic of interest. Octopuses don’t see in the same wavelengths as humans, so understanding how they sense other creatures and objects in their environment can help us better understand how to develop better sight technology, other tools that could be useful in science.

They also have vision that is polarized. Polarized vision is widespread in nature, and can be found in several different species. Polarization vision is the ability for creatures to see surfaces that reflect light at higher degrees than normal when their electric field comes into contact with it. You can see this “polarized effect” when you look at a highway road in the dark, or sheet plastic, glass, or water. All of these materials have a high degree of refraction.

However, every species processes these reflections and refractions differently. Thresholds for seeing polarized light can vary. Especially in Cephalopods.

Finally, Let’s talk about the arms of octopuses. They are so incredibly durable, that scientists and engineers have started to mimic them in robots.There have been several dynamic models of octopus arms out there, but let’s focus on one for today.

A team at Taishan Medical University in 2015 also created an octopus arm. This one was built to realize and mimic the large degrees of freedom an octopus’s arm has. They used coupled CPGs (Central Pattern Generators) to create the movement in the arms. CPGs are popular to use in autonomous robots because they can be programmed to complete basic tasks over and over.

They also used soft materials to strengthen the arms and made them fairly elastic. By using multiple CPGs they were able to finesse the locomotion of the arms in different areas, and simulate movement in a neuromuscular system.