Totally Unexpected: Scientists Discover “An Entirely New Way of Designing a Nervous System” - SciTechDaily

Octopuses are not similar humans – they are invertebrates with 8 arms and are much intimately related to clams and snails. Despite this, they person evolved analyzable tense systems with arsenic galore neurons arsenic successful the brains of dogs, allowing them to grounds a wide scope of analyzable behaviors.

This makes them an absorbing taxable for researchers similar Melina Hale, Ph.D., William Rainey Harper Professor of Organismal Biology and Vice Provost astatine the University of Chicago, who privation to recognize however alternate tense strategy structures tin execute the aforesaid functions arsenic those successful humans, specified arsenic sensing limb question and controlling movement.

In a caller survey published successful Current Biology, Hale and her colleagues discovered a caller and astonishing diagnostic of the octopus tense system: a operation that allows the intramuscular nervus cords (INCs), which assistance the octopus consciousness its limb movement, to link arms connected other sides of the animal.

The startling find provides caller insights into however invertebrate taxon person independently evolved analyzable tense systems. It tin besides supply inspiration for robotic engineering, specified arsenic caller autonomous underwater devices.

“In my lab, we survey mechanosensation and proprioception — however the question and positioning of limbs are sensed,” said Hale. “These INCs person agelong been thought to beryllium proprioceptive, truthful they were an absorbing people for helping to reply the kinds of questions our laboratory is asking. Up until now, determination hasn’t been a batch of enactment done connected them, but past experiments had indicated that they’re important for limb control.”

Thanks to the enactment for cephalopod probe offered by the Marine Biological Laboratory, Hale and her squad were capable to usage young octopuses for the study, which were tiny capable to let the researchers to representation the basal of each 8 arms astatine once. This fto the squad hint the INCs done the insubstantial to find their path.

“These octopuses were astir the size of a nickel oregon possibly a quarter, truthful it was a process to affix the specimens successful the close predisposition and to get the space close during the sectioning [for imaging],” said Adam Kuuspalu, a Senior Research Analyst astatine UChicago and the pb writer connected the study.

Initially, the squad was studying the larger axial nervus cords successful the arms but began to announcement that the INCs didn’t halt astatine the basal of the arm, but alternatively continued retired of the limb and into the assemblage of the animal. Realizing that small enactment had been done to research the anatomy of the INCs, they began to hint the nerves, expecting them to signifier a ringing successful the assemblage of the octopus, akin to the axial nervus cords.

Through imaging, the squad determined that successful summation to moving the magnitude of each arm, astatine slightest 2 of the 4 INCs widen into the assemblage of the octopus, wherever they bypass the 2 adjacent arms and merge with the INC of the 3rd limb over. This signifier means that each the arms are connected symmetrically.

It was challenging, however, to find however the signifier would clasp successful each 8 arms. “As we were imaging, we realized, they were not each coming unneurotic arsenic we expected, they each look to beryllium going successful antithetic directions, and we were trying to fig retired however if the signifier held for each of the arms, however would that work?” said Hale. “I adjacent got retired 1 of those children’s toys — a Spirograph — to play astir with what it would look like, however it would each link successful the end. It took a batch of imaging and playing with drawings portion we wracked our brains astir what could beryllium going connected earlier it became wide however it each fits together.”

The results were not astatine each what the researchers expected to find.

“We deliberation this is simply a caller plan for a limb-based tense system,” said Hale. “We haven’t seen thing similar this successful different animals.”

The researchers don’t yet cognize what relation this anatomical plan mightiness serve, but they person immoderate ideas.

“Some older papers person shared absorbing insights,” said Hale. “One survey from the 1950s showed that erstwhile you manipulate an limb connected 1 broadside of the octopus with lesioned encephalon areas, you’ll spot the arms responding connected the different side. So it could beryllium that these nerves let for decentralized power of a reflexive effect oregon behavior. That said, we besides spot that fibers spell retired from the nervus cords into the muscles each on their tracts, truthful they mightiness besides let for a continuity of proprioceptive feedback and centrifugal power on their lengths.”

The squad is presently conducting experiments to spot if they tin summation insights into this question by parsing retired the physiology of the INCs and their unsocial layout. They are besides studying the tense systems of different cephalopods, including squid and cuttlefish, to spot if they stock akin anatomy.

Ultimately, Hale believes that successful summation to illuminating the unexpected ways an invertebrate taxon mightiness plan a tense system, knowing these systems tin assistance successful the improvement of caller engineered technologies, specified arsenic robots.

“Octopuses tin beryllium a biologic inspiration for the plan of autonomous undersea devices,” said Hale. “Think astir their arms — they tin crook anywhere, not conscionable astatine joints. They tin twist, widen their arms, and run their suckers, each independently. The relation of an octopus limb is simply a batch much blase than ours, truthful knowing however octopuses integrate sensory-motor accusation and question power tin enactment the improvement of caller technologies.”

Reference: “Multiple nervus cords link the arms of octopuses, providing alternate paths for inter-arm signaling” by Adam Kuuspalu, Samantha Cody and Melina E. Hale, 28 November 2022, Current Biology.
DOI: 10.1016/j.cub.2022.11.007

The survey was funded by the United States Office of Naval Research.