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Octopus arms have segmented nervous systems to power extraordinary movements

The large nerve cord running down each octopus arm is separated into segments, giving it precise control over movements and creating a spatial map of its suckers.

University of Chicago

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Octopus arms move with incredible dexterity, bending, twisting, and curling with nearly infinite degrees of freedom.

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Credit: Cassady Olson

Octopus arms move with incredible dexterity, bending, twisting, and curling with nearly infinite degrees of freedom. New research from the University of Chicago revealed that the nervous system circuitry that controls arm movement in octopuses is segmented, giving these extraordinary creatures precise control across all eight arms and hundreds of suckers to explore their environment, grasp objects, and capture prey.

“If you're going to have a nervous system that's controlling such dynamic movement, that's a good way to set it up,” said Clifton Ragsdale, PhD, Professor of Neurobiology at UChicago and senior author of the study. “We think it’s a feature that specifically evolved in soft-bodied cephalopods with suckers to carry out these worm-like movements.”

The study, “Neuronal segmentation in cephalopod arms,” was published January 15, 2025, in Nature Communications.

Each octopus arm has a massive nervous system, with more neurons combined across the eight arms than in the animal’s brain. These neurons are concentrated in a large axial nerve cord (ANC), which snakes back and forth as it travels down the arm, every bend forming an enlargement over each sucker.

Cassady Olson, a graduate student in Computational Neuroscience who led the study, wanted to analyze the structure of the ANC and its connections to musculature in the arms of the California two-spot octopus (Octopus bimaculoides), a small species native to the Pacific Ocean off the coast of California. She and her co-author Grace Schulz, a graduate student in Development, Regeneration and Stem Cell Biology, were trying to look at thin, circular cross-sections of the arms under a microscope, but the samples kept falling off the slides. They tried lengthwise strips of the arms and had better luck, which led to an unexpected discovery.

Using cellular markers and imaging tools to trace the structure and connections from the ANC, they saw that neuronal cell bodies were packed into columns that formed segments, like a corrugated pipe. These segments are separated by gaps called septa, where nerves and blood vessels exit to nearby muscles. Nerves from multiple segments connect to different regions of muscles, suggesting the segments work together to control movement.

“Thinking about this from a modeling perspective, the best way to set up a control system for this very long, flexible arm would be to divide it into segments,” Olson said. “There has to be some sort of communication between the segments, which you can imagine would help smooth out the movements.”

Nerves for the suckers also exited from the ANC through these septa, systematically connecting to the outer edge of each sucker. This indicates that the nervous system sets up a spatial, or topographical, map of each sucker. Octopuses can move and change the shape of their suckers independently. The suckers are also packed with sensory receptors that allow the octopus to taste and smell things that they touch—like combining a hand with a tongue and a nose. The researchers believe the “suckeroptopy,” as they called the map, facilitates this complex sensory-motor ability.

To see if this kind of structure is common to other soft-bodied cephalopods, Olson also studied longfin inshore squid (Doryteuthis pealeii), which are common in the Atlantic Ocean. These squid have eight arms with muscles and suckers like an octopus, plus two tentacles. The tentacles have a long stalk with no suckers, with a club at the end that does have suckers. While hunting, the squid can shoot the tentacles out and grab prey with the sucker-equipped clubs.

Using the same process to study long strips of the squid tentacles, Olson saw that the ANC in the stalks with no suckers are not segmented, but the clubs at the end are segmented the same way as the octopus. This suggests that a segmented ANC is specifically built for controlling any type of dexterous, sucker-laden appendage in cephalopods. The squid tentacle clubs have fewer segments per sucker, however, likely because they do not use the suckers for sensation the same way octopuses do. Squid rely more on their vision to hunt in the open water, whereas octopuses prowl the ocean floor and use their sensitive arms as tools for exploration.

While octopuses and squid diverged from each other more than 270 million years ago, the commonalities in how they control parts of their appendages with suckers—and differences in the parts that don’t—show how evolution always manages to find the best solution.

“Organisms with these sucker-laden appendages that have worm-like movements need the right kind of nervous system,” Ragsdale said. “Different cephalopods have come up with a segmental structure, the details of which vary according to the demands of their environments and the pressures of hundreds of millions of years of evolution.”

University of Chicago

Octopus bimaculoides

Octopus bimaculoides

Octopus bimaculoides

Octopus bimaculoides

Octopus bimaculoides

Credit

Cassady Olson

Journal

Nature Communications

DOI

10.1038/s41467-024-55475-5 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Neuronal segmentation in cephalopod arms

Article Publication Date

15-Jan-2025

 

Indigenous students face cumbersome barriers to attaining post-secondary education

Indigenous university students, nearly half of whom have children, struggle to afford post-secondary education, find affordable housing, and afford childcare. On-campus resource centers can help mitigate barriers and enhance belonging

University of Toronto

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Indigenous students identified inadequate funding as a major barrier to completing post-secondary education according to a new study published in AlterNative: An International Journal of Indigenous Peoples.

The study surveyed Indigenous university students at Algoma University. The students, who identified as either First Nations or Métis, reported that they required multiple sources of funding, including government student loans and personal savings, to afford their post-secondary education. About two-thirds (69%) of students received funding for their education from First Nations sources, including funding from federal programs for Indigenous students. 

 “This research sheds light on helpful strategies to creatively support Indigenous students in post-secondary education,” says first author, Dr. Rose E. Cameron, (Anishinaabekwe), an Associate Professor of Social Work at Algoma University. “It also provides new insight into how institutions can help minimize the barrier Indigenous students face.” 

The survey asked Indigenous students how universities can better support them. Students suggested that social events for Indigenous students, on-campus childcare, and mentorship opportunities for Indigenous students would help to decrease isolation and cultivate a sense of belonging in campus. The research findings underscored how resources centres, cultural events and mentorship opportunities can boost the resilience of Indigenous students by helping them feel included, supported, and socially connected on campus.

“The Anishinaabe Academic Resource Centre at Algoma University is a model for other institutions looking to support students with Indigenous ancestry,” says Deanna Naveau-Heyde (Mattagami First Nation), a research assistant at Algoma University. “It offers a host of culturally affirming events including Pow Wows, sharing circles, moccasin-making, visiting Elders and feasts.” 

With more Indigenous students graduating from high school than ever before, it is important for programs to provide both cultural and financial support, say the researchers. “Funding and supports for Indigenous students needs to keep pace with their increase in numbers, which unfortunately has not been the case,” says Meghan Bird, a research assistant at the Factor-Inwentash Faculty of Social Work at the University of Toronto.  

Nearly half (47%) of students in this study had children, with most students having 2-3 children in their care. In comparison, only 11% of non-Indigenous post-secondary students are parents. Nearly all the Indigenous parents in this survey were enrolled in university full-time. They reported that having children while in university can make finding housing, affording childcare, and balancing studies significantly more challenging. 

“Most of the Indigenous students in our study faced significant financial difficulties, which can impact their ability to complete their studies,” said Esme Fuller-Thomson, Professor at the Factor-Inwentash Faculty of Social Work and Director of the Institute of Life Course and Aging at the University of Toronto. “While our study only surveyed Indigenous students currently enrolled in university, future research would benefit from surveying Indigenous students who had to leave school due to inadequate funding.” 

For many Indigenous students, the transition from their home reservation to urban university campus is especially difficult. Many fear losing their connection to family, community, and culture. 

The authors argue that institutions of higher education across Canada can benefit from surveying their students with Indigenous ancestry to better understand how to support them in their pursuit of higher education. 

“All institutes of higher education should provide financial assistance and fund specialized resource centers to support their students with Indigenous ancestry academically and socially,” says Cameron.

Source Article

Cameron, R. E., Bird, M. J., Naveau-Heyde, D. D., & Fuller-Thomson, E. (2024). Creating a 

“sense of belonging” for Indigenous students: identifying supports to improve access and success in post-secondary education. AlterNative: An International Journal of Indigenous Peoples,

 

Author’s Note

Rose E. Cameron (Anishinaabekwe) (PhD) is an Associate Professor in the School of Social Work at Algoma University, Canada. Meghan J. Bird (BASc Hons., MSW) is a Canadian Social Worker, Therapist, and research assistant at the Factor-Inwentash Faculty of Social Work at the University of Toronto. Deanna D. Naveau-Heyde (Mattagami First Nation) (BS Hons., CESD) is affiliated with Algoma University, Canada. Esme Fuller-Thomson (PhD) is Professor and Director at the Institute for Life Course and Aging, Factor-Inwentash, Faculty of Social Work at the University of Toronto, Canada.

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Journal

AlterNative An International Journal of Indigenous Peoples

DOI

10.1177/11771801241291242 

Method of Research

Survey

Subject of Research

People

Article Title

Creating a “sense of belonging” for Indigenous students: identifying supports to improve access and success in post-secondary education.

 

SeoulTech researchers propose a novel method to shed light on PFOS-induced neurotoxicity

The strategy simultaneously extracts lipids and metabolites from zebrafish embryos to study perfluorooctanesulfonate (PFOS)-induced neurotoxicity

Seoul National University of Science & Technology

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Using a newly proposed extraction strategy, researchers simultaneously analyze metabolomics and lipidomics of neurotoxicity in zebrafish embryos, revealing many lipids and metabolites involved in the toxicity pathways. These findings advance our understanding of environmental toxicity using multi-omics analyses.

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Credit: Professor Ki-Tae Kim from SEOULTECH

The term “omics” refers to the study of entirety of molecular mechanisms that happen inside an organism. With the advent of omics technologies like transcriptomics, proteomics, metabolomics, and lipidomics, our understanding of molecular pathways of toxic environmental pollutants has deepened. But most environmental toxicology studies are still dependent on a single-omics analyses, leading to gaps in our understanding of integrated toxicity pathways of pollutants. Researchers from all over the world have been trying to build reliable biomolecule analyses by designing multi-omics studies from a single biological sample. Although such advances have been reported from various model systems like mammalian cells, Caenorhabditis elegans, etc., toxicology studies on zebrafish are still based on a single-omics analyses using individually prepared biological samples. However, selection of appropriate extraction solvents and pooling size for accurate omics analyses is still a challenge in zebrafish toxicology studies.

To address this gap, a research team led by Professor Ki-Tae Kim has now proposed a novel approach for simultaneous extraction of metabolites and lipids for multi-omics analyses from a single sample using zebrafish embryos. Their study was published in the Journal of Hazardous Materials, made available online on 28 November, 2024.

For this, the researchers used a methyl tert-butyl ether (MTBE)-based extraction strategy using a single biological sample from zebrafish embryos for simultaneous metabolomics and lipidomics analyses. Explaining further, Prof. Kim says, “To increase the applicability of our findings to environmental toxicology, we elucidated the biomolecular mechanisms underlying PFOS-induced neurobehavioral changes and evaluated the analytical performance of the MTBE-based strategy by comparing it with previous findings of PFOS-induced metabolomic dysregulation.”

In their study, Prof. Kim and his team determined the optimal embryo pooling size for the application of MTBE-based extraction. The inter-sample variation was the least when 30 or more larvae were used. They thus suggest using 30 larvae as the optimum pooling size for the simultaneous analysis of metabolomics and lipidomics. Their novel extraction strategy also revealed many lipids and metabolites compared to the conventionally used extraction solvents. Application of the MTBE-based strategy helped record the changes in metabolites and lipids linked to energy metabolism in PFOS-exposed zebrafish larvae.

“The disruption of metabolites and lipids revealed the biomolecular mechanism underlying the alteration of larval behavior by affecting biological processes like energy metabolism including disrupted amino acids and fatty acids metabolism”, says Prof. Kim. Further, the comprehensive profiling of biomolecular dysregulations in this study helped identify sphingolipids as a reliable biomarker of PFOS-induced neurotoxicity. This approach of using a single sample for multi-omics study can be expanded to a variety of biomolecules, leading to the management of toxicity at the biomolecular level. Furthermore, the proposed approach can help in developing a safer and healthier environment in future by facilitating research on the measure of exposure to environmental pollutants.

As is well known, PFOS is one of the most prevalent environmental pollutants commonly found in aquatic ecosystems. Biomonitoring studies have reported high concentrations of it in water, human blood and even human cerebrospinal fluid. Reliable analysis of biomolecules in a single sample is indispensable for multi- and integrative omics, with wide applications in understanding molecular dysregulations by such toxic chemicals. Highlighting the potential of this strategy for expediting such analysis, Prof. Kim says, “The developed method will trigger mechanism-based classification studies of per- and polyfluoroalkyl substances and contribute to the advancement of multi-omics analysis technologies in environmental toxicology.”  

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Reference

DOI: 10.1016/j.jhazmat.2024.136712

 

About the institute Seoul National University of Science and Technology (SEOULTECH)

Seoul National University of Science and Technology, commonly known as 'SEOULTECH,' is a national university located in Nowon-gu, Seoul, South Korea. Founded in April 1910, around the time of the establishment of the Republic of Korea, SEOULTECH has grown into a large and comprehensive university with a campus size of 504,922 m2. It comprises 10 undergraduate schools, 35 departments, 6 graduate schools, and has an enrollment of approximately 14,595 students.

Website: https://en.seoultech.ac.kr/

 

About Professor Ki-Tae Kim

Prof. Ki-Tae Kim is a Professor of Environmental engineering at Seoul National University Science and Technology. His group focuses on exploring the adverse effects and toxicity mechanisms of environmental toxicants on ecosystems and humans using zebrafish models. Notably, they have established top-tier research infrastructure for zebrafish models in South Korea, including breeding facilities and behavioral effects measurement systems. Furthermore, we are pioneering research that comprehensively identifies complex mechanisms using various molecular toxicology methods and toxicoinformatics. His work also includes the development of non-experimental toxicity assessment methods and research related to regulatory toxicology, establishing unique research expertise.

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Journal

Journal of Hazardous Materials

DOI

10.1016/j.jhazmat.2024.136712 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

Applying newly suggested simultaneous analysis of metabolomics and lipidomics into perfluorooctanesulfonate-derived neurotoxicity mechanism in zebrafish embryos

 

New study shows that corn-soybean crop rotation benefits are extremely sensitive to climate

Understanding sustainable practices could help improve yields as climate extremes threaten global food security

University of Minnesota

 

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Despite climate challenges, the study suggests increasing crop rotation can still improve overall yields and highlights its potential as a climate adaptation strategy.

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Credit: University of Minnesota Twin Cities

MINNEAPOLIS / ST. PAUL (01/15/2024) — A study by researchers at the University of Minnesota Twin Cities offers new insights into how alternating corn and soybean crops can help increase crop yield in a changing climate.

The research is published in the peer-reviewed scientific journal Global Change Biology.

Rising temperatures and weather extremes are threatening global food security, making it crucial to understand how sustainable practices like crop rotation can help improve agricultural yields and resilience.

The study found that the benefits to corn-soybean rotation, compared to continuous corn year after year, are extremely sensitive to climate. For example, corn benefits from a rotation of soybeans in colder areas, while soybean benefits from a rotation of corn in warmer regions. In addition, warming during the non-growing season reduces the corn benefits, while warming in the growing season helps boost the soybean benefits.

“Corn and soybeans may experience different crop rotation benefit changes in the future, which can help U.S. farmers make more informed decisions when facing climate warming,” said Junxiong Zhou, Ph.D. candidate in University of Minnesota’s Department of Bioproducts and Biosystems Engineering (BBE) and first author on the paper.

Despite climate challenges, the study suggests increasing crop rotation can still improve overall yields and highlights its potential as a climate adaptation strategy.

While most prior studies have focused on the current climate conditions, this new study takes into account a changing climate in the future and how crop rotation is impacted by it. To address this, the researchers used satellite data combined with what they call a “causal forest model,” a scientific method that helps to understand cause-and-effect relationships in data. They estimated the benefits of crop rotation under varying climate conditions in the Midwest region of the United States.

“Millions of satellite observations and advanced machine learning models enable us to quantify the climate impacts on crop rotation benefits at the subfield level over the Midwest,” said Zhenong Jin, an associate professor in BBE and senior author on the paper.

To analyze this enormous amount of data, the researchers used an advanced machine learning tool that teaches computers to learn from examples and improve at tasks without being explicitly programmed. This helped the team understand how crop rotation benefits corn and soybean yields in the U.S. Midwest. 

“This study demonstrates the great potential of interpretable machine learning for estimating large-scale effects of agricultural management practices,” said David Mulla, a professor and Larson Endowed Chair in soil and water resources at the U of M’s College of Food, Agricultural and Natural Resource Sciences, and a senior researcher at the AI Institute for Climate-Land Interactions, Mitigation, Adaptation, Tradeoffs and Economy (AI-CLIMATE).

In the future, the researchers hope to expand their analysis to include long-term diverse crop rotation systems and their interactions with all season climates. Future studies will work to focus on field-level studies to understand nutrient cycling and pest dynamics under varying climate scenarios, alongside exploring advancements like pest-resistant crops.

In addition to Jin and Zhou, the research team included Peng Zhu from The University of Hong Kong along with Dan M. Kluger and David B. Lobell from Stanford University.

This research is supported by the National Science Foundation (NSF) Smart and Connected Community project and the U.S. Department of Agriculture’s (USDA) National Institute of Food and Agriculture AI-CLIMATE project.

Read the entire research paper titled, “Changes in the Yield Effect of the Preceding Crop in the US Corn Belt Under a Warming Climate,” visit the Wiley Online Library website. A commentary piece on the research can also be found on the Wiley Online Library website. 

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Journal

Global Change Biology

DOI

10.1111/gcb.17556 

Article Title

Changes in the Yield Effect of the Preceding Crop in the US Corn Belt Under a Warming Climate

A

 

Hiroshima flooding: A case study of well usage and adaptive governance

Groundwater and multilevel cooperation in recovery efforts mitigated water crisis after flooding

Osaka Metropolitan University

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Following free inspection incentives, private household wells were opened to the public during water outages. Pictured here is a well with a notice that warns the water needs to be boiled before drinking.

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Credit: Osaka Metropolitan University

Society is often vulnerable to disasters, but how humans manage during and after can turn devastation into opportunities for improved resilience.

For instance, private wells are attracting attention as an alternative resource for securing water for daily use and consumption in the event the water supply is cut off after a disaster. However, there are few records on how wells are used in the confusion of disasters, so detailed research is needed to promote the use of emergency wells.

Professor Takahiro Endo of the Graduate School of Sustainable System Sciences at Osaka Metropolitan University conducted a survey on the use of groundwater in Kure, Hiroshima Prefecture, during water supply disruptions due to the 2018 west Japan floods. The study examined actual implementation of adaptive governance, where multiple levels of government, nonprofits, and local individuals cooperate in achieving a desired societal outcome.

It was discovered that Hiroshima Prefecture, in agreement with the water quality inspection organization Hiroshima Environment and Health Association, had provided a free water inspection service for well owners after the water outage. This promoted the initiative to have the inspected wells open to the public. These collaborative efforts made it possible for wells to become available in a short period of time and supplemented the emergency water supply activities of local governments.

“This is a case of emergency water supply policy that makes use of the economic incentive of free water quality testing, which could be a model policy for other local governments considering the introduction of disaster wells,” stated Professor Endo.

These findings were published in Water International.

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About OMU 

Established in Osaka as one of the largest public universities in Japan, Osaka Metropolitan University is committed to shaping the future of society through “Convergence of Knowledge” and the promotion of world-class research. For more research news, visit https://www.omu.ac.jp/en/ and follow us on social media: X, Facebook, Instagram, LinkedIn.

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Journal

Water International

DOI

10.1080/02508060.2024.2423451 

Method of Research

Case study

Subject of Research

People

Article Title

Adaptive governance and evolution of a groundwater-based resilient city: a case study of Kure City, Japan