Fluorescent picture of the octopus brain revealing the area of various various kinds of nerve cells Credit: Niell Lab
It’s difficult for the octopus to choose simply one celebration technique. This stunning animal swims through jet propulsion, shoots dark chemicals at its opponents, and can alter its skin to mix in with its environments within seconds.
Now, a group of University of Oregon (UO) scientists has actually examined yet another distinguishing characteristic of this eight-armed marine animal: its impressive visual abilities.
They set out an in-depth map of the octopus’s visual system in a brand-new clinical paper. In the map, they categorize various kinds of nerve cells in a part of the brain dedicated to vision. This leads to is an important resource for other neuroscientists, offering information that might assist future experiments. In addition, it might teach us something about the advancement of brains and visual systems more broadly.
The group reports their findings today (October 31) in the journal Current Biology
Cris Niell’s laboratory at the UO research studies vision, mainly in mice. But a couple of years earlier, postdoc Judit Pungor brought a brand-new types to the laboratory– the California two-spot octopus.
Although it is not typically utilized as a research study topic in the laboratory, this cephalopod rapidly recorded the interest of UO neuroscientists. Unlike mice, which are not understood for having great vision, “octopuses have an amazing visual system, and a large fraction of their brain is dedicated to visual processing,” Niell stated. “They have an eye that’s incredibly comparable to the human eye, however after that, the brain is totally various.
The last typical forefather in between octopuses and human beings was 500 million years earlier, and the types have actually because progressed in extremely various contexts. So researchers didn’t understand whether the parallels in visual systems extended beyond the eyes, or whether the octopus was rather utilizing totally various sort of nerve cells and brain circuits to accomplish comparable outcomes.
“Seeing how the octopus eye convergently progressed likewise to ours, it’s cool to consider how the octopus visual system might be a design for comprehending brain intricacy more typically,” stated Mea Songco-Casey, a college student in Niell’s laboratory and the very first author on the paper. “For example, are there fundamental cell types that are required for this very intelligent, complex brain?”
Here, the group utilized hereditary methods to recognize various kinds of nerve cells in the octopus’s optic lobe, the part of the brain that’s dedicated to vision.
They chose 6 significant classes of nerve cells, differentiated based upon the chemical signals they send out. Looking at the activity of particular genes in those nerve cells then exposed more subtypes, offering ideas to more particular functions.
In some cases, the researchers identified specific groups of nerve cells in distinct spatial plans– for instance, a ring of nerve cells around the optic lobe that all signal utilizing a particle called octopamine. Fruit flies usage this particle, which resembles adrenaline, to increase visual processing when the fly is active. So it might maybe have a comparable function in octopuses.
“Now that we know there’s this very specific cell type, we can start to go in and figure out what it does,” Niell stated.
About a 3rd of the nerve cells in the information didn’t rather look completely established. The octopus brain keeps growing and including brand-new nerve cells over the animal’s life-span. These immature nerve cells, not yet incorporated into brain circuits, signified the brain in the procedure of broadening!
However, the map didn’t expose sets of nerve cells that plainly moved over from human beings or other mammalian brains, as the scientists believed it might.
“At the obvious level, the neurons don’t map onto each other—they’re using different neurotransmitters,” Niell stated. “But maybe they’re doing the same kinds of computations, just in a different way.”
Digging much deeper will likewise need getting a much better manage on cephalopod genes. Because the octopus hasn’t typically been utilized as a laboratory animal, a number of the tools that are utilized for accurate hereditary adjustment in fruit flies or mice do not yet exist for the octopus, stated Gabby Coffing, a college student in Andrew Kern’s laboratory who dealt with the research study.
“There are a lot of genes where we have no idea what their function is, because we haven’t sequenced the genomes of a lot of cephalopods,” Pungor stated. Without hereditary information from associated types as a point of contrast, it’s more difficult to deduce the function of specific nerve cells.
Niell’s group is up for the obstacle. They’re now working to map the octopus brain beyond the optic lobe, seeing how a few of the genes they concentrated on in this research study appear somewhere else in the brain. They are likewise tape-recording from nerve cells in the optic lobe, to identify how they process the visual scene.
In time, their research study may make these mystical marine animals a little less dirty– and shine a little light on our own advancement, too.
Reference: “Cell types and molecular architecture of the Octopus bimaculoides visual system” 31 October 2022, Current Biology
DOI: 10.1016/ j.cub.202210015
