Evolution in action? New study finds possibility of nitrogen-fixing organelles

UNIVERSITY OF RHODE ISLAND

KINGSTON, R.I.—April 3, 2024—Nitrogen is a nutrient essential for all life on Earth. Although nitrogen gas (N2) is plentiful, it is largely unavailable to most organisms without a process known as nitrogen fixation, which converts dinitrogen to ammonium—a major inorganic nitrogen source.

While there are bacteria that are able to reduce dinitrogen to ammonium, researchers at the University of Rhode Island, Institut de Ciències del Mar in Barcelona, University of California at Santa Cruz and the Massachusetts Institute of Technology have discovered nitrogen-fixing symbiotic organisms exhibiting behaviors similar to organelles. In fact, researchers posit these symbiotic organisms – UCYN-A, a species of cyanobacteria – may be evolving organelle-like characteristics. Their study was recently published in the journal Cell.

UCYN-A live in a symbiotic relationship with a closely related group of marine algae, B. bigelowii, in areas of the open ocean that are often low in nutrients. Most nitrogen-fixing bacteria have mechanisms to regulate dinitrogen use when fixed sources of nitrogen are available, alleviating the high energetic cost of this process. However, UCYN-A have lost the genes allowing this and are able to fix nitrogen gas into ammonium even in nutrient-rich environments. The host, in-turn, provides it with carbon fixed photosynthetically by its chloroplasts.    

The study details how researchers found a size relationship between UCYN-A and their symbiotic partner cells – consistent with the size relationships between other organelles and their hosts. As organelles get larger, so do their host cells ­– eventually dividing and replicating. Mathematical modeling revealed the metabolic trade-offs which regulate the relative cell size through nutrient acquisition and exchange.

“It requires lots of energy as well as electrons to fix nitrogen gas, to make it into something useful,” said Keisuke Inomura, assistant professor of oceanography at URI’s Graduate School of Oceanography and one of the study’s lead authors. “If UCYN-A are moving along the evolutionary path toward developing into nitrogen-fixing organelles and we find cells aside from B. bigelowii also have such organelles, or are evolving similarly, it could be a game-changer.”

While organelles such as mitochondria and chloroplasts are much further along on the evolutionary spectrum, researchers contend that what they are seeing may be a snapshot of the evolutionary process of bacterial-derived organelles that are nitrogen-fixing.

“Our study focuses on a much more recent symbiotic relationship that emerged about 100 million years ago, allowing us to explore the evolution of organelle formation in its early stages,” explained Francisco Cornejo, co-lead author and postdoc researcher in the department of marine biology and oceanography at the Institut de Ciències del Mar.

Researchers note, however, that more study is needed to demonstrate whether this is the case.

“The surprisingly tight size relationship between UCYN-A and its host can be explained by the resource economy of the partners. It suggests that UCYN-A may be on the path to becoming an organelle: whether it may already be so is the subject of ongoing research,” said Michael J. Follows, professor of earth, atmospheric and planetary sciences at MIT and a member of the research team.

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JOURNAL

Cell

DOI

10.1016/j.cell.2024.02.016 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

Metabolic tradeoffs constrain the cell size ratio in a nitrogen-fixing symbiosis

 

Might your personality affect how you move? Runners classified as Myers-Briggs "Sensing" types have a more grounded running style in experiments than those classified as "Intuition" types

PLOS

 

IMAGE: 

PERSONALITY AFFECTS HOW YOU MOVE. RUNNERS CLASSIFIED AS MYERS-BRIGGS "SENSING" TYPES HAVE A MORE GROUNDED RUNNING STYLE THAN THOSE CLASSIFIED AS "INTUITION" TYPES. CONVERSELY, “INTUITION” RUNNERS HAVE A MORE DYNAMIC AND ELASTIC RUNNING STYLE THAN “SENSING” RUNNERS.

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CREDIT: RUN 4 FFWPU, PEXELS, CC0 (HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)

Might your personality affect how you move? Runners classified as Myers-Briggs "Sensing" types have a more grounded running style in experiments than those classified as "Intuition" types

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Article URL:  https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0300108

Article Title: Mind to move: Differences in running biomechanics between sensing and intuition shod runners

Author Countries: France, Switzerland, Belgium

Funding: The author(s) received no specific funding for this work.

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JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0300108 

ARTICLE TITLE

Mind to move: Differences in running biomechanics between sensing and intuition shod runners

ARTICLE PUBLICATION DATE

3-Apr-2024

 

Working outside the typical 9–5 in younger adulthood may be linked with worse health decades later

Employees with volatile work schedules early in their career had worse sleep and more depressive symptoms at age 50

Peer-Reviewed Publication

PLOS

 

IMAGE: 

THE HOURS YOU WORK EARLIER IN LIFE MAY BE ASSOCIATED WITH WORSE HEALTH YEARS LATER.

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CREDIT: ARIVLEONE, PIXABAY, CC0 (HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)

The hours you work earlier in life may be associated with worse health years later, according to a study published April 3, 2024 in the open-access journal PLOS ONE by Wen-Jui Han from New York University, US.

Studies have consistently shown that nonstandard work schedules—working outside the traditional nine-to-five workday—can negatively impact physical and mental health as well as social and family life. The current study uses a life-course approach to provide a longer-term perspective on how work schedule patterns throughout a person’s working life impact their health in middle age.

Han used data from The National Longitudinal Survey of Youth-1979 (NLSY79), which includes data on more than 7,000 people in the US over 30 years, to see whether employment patterns in younger adulthood were associated with sleep, physical health, and mental health at age 50.

Han found that around a quarter of participants (26%) worked stable standard hours, with a further third (35%) working mostly standard hours. 17 percent initially worked standard hours in their 20s, later transitioning into volatile working patterns – a combination of evening, night, and variable hours. 12 percent initially worked standard hours and then switched to variable hours. A final ten percent were mostly not working over this period.

Compared to individuals who mostly worked during traditional daytime hours throughout their working career, those whose careers featured more volatile work schedules slept less, had lower sleep quality, and were more likely to report depressive symptoms at age 50. The most striking results were seen in those who had stable work hours in their 20s and then transitioned to more volatile work hours in their 30s. This effect size was significant and similar to that of being educated only to below high school level.

Han also found racial and gender-related trends. For example, Black Americans were more likely to have volatile work schedules associated with poorer health, highlighting how some groups may disproportionately shoulder the adverse consequences of such employment patterns.

Han suggests that volatile work schedules are associated with poor sleep, physical fatigue, and emotional exhaustion, which may make us vulnerable to an unhealthy life. The study also suggests that positive and negative impacts of work schedules on health can accumulate over one’s lifetime while highlighting how employment patterns can contribute to health inequities.

Han adds: “Work that is supposed to bring resources to help us sustain a decent life has now become a vulnerability to a healthy life due to the increasing precarity in our work arrangements in this increasingly unequal society. People with vulnerable social positions (e.g., females, Blacks, low-education) disproportionately shoulder these health consequences.”

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Author Interview: https://plos.io/4av5Elr

In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0300245

Citation: Han W-J (2024) How our longitudinal employment patterns might shape our health as we approach middle adulthood—US NLSY79 cohort. PLoS ONE 19(4): e0300245. https://doi.org/10.1371/journal.pone.0300245

Author Countries: USA

Funding: The author received no specific funding for this work.

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JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0300245 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

How our longitudinal employment patterns might shape our health as we approach middle adulthood—US NLSY79 cohort

ARTICLE PUBLICATION DATE

3-Apr-2024

 

Air quality in schools: Shielding kids with intellectual and developmental disabilities from COVID

UNIVERSITY OF ROCHESTER MEDICAL CENTER

During the pandemic, University of Rochester Medical Center (URMC) researchers, including those from the Intellectual and Developmental Disabilities Research Center (IDDRC), teamed up with the Mary Cariola Center to study ways to prevent COVID infection among children with intellectual and developmental disabilities (IDD), a particularly vulnerable population. Together, they found that good airflow and filtration in schools may help these children and their teachers avoid COVID infections.

The COVID pandemic was a particularly difficult balancing act for children with IDDs and their families. The Mary Cariola Center, a special education school in Rochester, NY, serves more than 450 students ages 3-21 with severe IDDs and complex medical needs. Many of these children are at heightened risk for infection, but they may also struggle with protective measures, like masking and distancing. Many students rely on the Center for needed services and therapy, so it was imperative to keep these kids in school—and to make sure school was as safe as possible.

With an eye toward expanding the limited COVID prevention toolbox available to these children, URMC researchers and Mary Cariola Center administrators turned their attention toward airflow and filtration in the school.

“COVID, like flu and RSV, is primarily spread through the air,” said  Martin Zand, MD, PhD, dean’s professor of Medicine and senior associate dean for Clinical Research at URMC, who co-led the study. “The virus that causes COVID can circulate in the air for up to three hours, so the quicker you filter or circulate out that air, the better.”

Zand, who is also a co-director of the Clinical and Translational Science Institute at URMC, and colleagues from across the Medical Center measured levels of carbon dioxide, a gas we breathe out, in 100 rooms across three buildings on the Mary Cariola Center campus. While not a direct measure, carbon dioxide offers a relatively easy way to estimate ventilation: lower levels of carbon dioxide indicate better ventilation and air quality.

All 100 rooms, which varied in size and purpose—from small classrooms, therapy rooms, and offices to large activity rooms and gyms—stayed well below the Occupational Safety and Health Administration’s carbon dioxide limit. And only three rooms appeared to have lower ventilation (carbon dioxide levels over 2,000 parts per million) for two or more hours during the testing period, which lasted one to three days.

However, many rooms reached moderate carbon dioxide levels (1,001-2,000 parts per million), which are generally safe, but may indicate less-than-optimal airflow. According to the study, the number of COVID cases recorded among people who spent time in a given room was linked to the amount of time that room had moderate carbon dioxide levels (i.e. suboptimal ventilation).

The research team also found a link between COVID cases and air filtration. One building on the Mary Cariola campus has a relatively new ventilation system that can support high efficiency air filters, called MERV-13, that can capture more virus particles.  The other two buildings have older systems that aren’t strong enough to move air through the tighter, high-efficiency filters. These systems use more porous MERV-11 filters that may allow more virus particles to circulate through the buildings.

Researchers found classrooms that relied on the more porous air filters had higher numbers of total COVID cases. However, the study was not designed to test if infections were acquired in or outside of school.  

Since conducting the study, the Mary Cariola Center has been working on several fronts to improve ventilation in any areas of concern across their campus.  They have also pursued state funding and begun conversations with property owners to make overall improvements to the ventilation systems.

While this study, published in PLOS, focused on testing airflow and filtration, it was part of a larger project funded by the National Institutes of Health Rapid Acceleration of Diagnostics-Underserved Populations program. That project, collaboratively led by Zand, John Foxe, PhD, director of the Del Monte Institute for Neuroscience and co-director of the UR-IDDRC, and Stephen Dewhurst, PhD, vice dean for research at the University, brought COVID testing to students and staff in the Mary Cariola Center and helped catch cases early to prevent spreading.

“One thing that COVID taught us is that there isn’t one single magic solution that will prevent all infection from all viruses,” said Zand. “Rather, a combination of approaches is most effective, including masking, vaccination, ventilation, and air filtration.”

During the pandemic, University of Rochester Medical Center (URMC) researchers, including those from the Intellectual and Developmental Disabilities Research Center (IDDRC), teamed up with the Mary Cariola Center to study ways to prevent COVID infection among children with intellectual and developmental disabilities (IDD), a particularly vulnerable population. Together, they found that good airflow and filtration in schools may help these children and their teachers avoid COVID infections.

The COVID pandemic was a particularly difficult balancing act for children with IDDs and their families. The Mary Cariola Center, a special education school in Rochester, NY, serves more than 450 students ages 3-21 with severe IDDs and complex medical needs. Many of these children are at heightened risk for infection, but they may also struggle with protective measures, like masking and distancing. Many students rely on the Center for needed services and therapy, so it was imperative to keep these kids in school—and to make sure school was as safe as possible.

With an eye toward expanding the limited COVID prevention toolbox available to these children, URMC researchers and Mary Cariola Center administrators turned their attention toward airflow and filtration in the school.

“COVID, like flu and RSV, is primarily spread through the air,” said  Martin Zand, MD, PhD, dean’s professor of Medicine and senior associate dean for Clinical Research at URMC, who co-led the study. “The virus that causes COVID can circulate in the air for up to three hours, so the quicker you filter or circulate out that air, the better.”

Zand, who is also a co-director of the Clinical and Translational Science Institute at URMC, and colleagues from across the Medical Center measured levels of carbon dioxide, a gas we breathe out, in 100 rooms across three buildings on the Mary Cariola Center campus. While not a direct measure, carbon dioxide offers a relatively easy way to estimate ventilation: lower levels of carbon dioxide indicate better ventilation and air quality.

All 100 rooms, which varied in size and purpose—from small classrooms, therapy rooms, and offices to large activity rooms and gyms—stayed well below the Occupational Safety and Health Administration’s carbon dioxide limit. And only three rooms appeared to have lower ventilation (carbon dioxide levels over 2,000 parts per million) for two or more hours during the testing period, which lasted one to three days.

However, many rooms reached moderate carbon dioxide levels (1,001-2,000 parts per million), which are generally safe, but may indicate less-than-optimal airflow. According to the study, the number of COVID cases recorded among people who spent time in a given room was linked to the amount of time that room had moderate carbon dioxide levels (i.e. suboptimal ventilation).

The research team also found a link between COVID cases and air filtration. One building on the Mary Cariola campus has a relatively new ventilation system that can support high efficiency air filters, called MERV-13, that can capture more virus particles.  The other two buildings have older systems that aren’t strong enough to move air through the tighter, high-efficiency filters. These systems use more porous MERV-11 filters that may allow more virus particles to circulate through the buildings.

Researchers found classrooms that relied on the more porous air filters had higher numbers of total COVID cases. However, the study was not designed to test if infections were acquired in or outside of school.  

Since conducting the study, the Mary Cariola Center has been working on several fronts to improve ventilation in any areas of concern across their campus.  They have also pursued state funding and begun conversations with property owners to make overall improvements to the ventilation systems.

While this study, published in PLOS, focused on testing airflow and filtration, it was part of a larger project funded by the National Institutes of Health Rapid Acceleration of Diagnostics-Underserved Populations program. That project, collaboratively led by Zand, John Foxe, PhD, director of the Del Monte Institute for Neuroscience and co-director of the UR-IDDRC, and Stephen Dewhurst, PhD, vice dean for research at the University, brought COVID testing to students and staff in the Mary Cariola Center and helped catch cases early to prevent spreading.

“One thing that COVID taught us is that there isn’t one single magic solution that will prevent all infection from all viruses,” said Zand. “Rather, a combination of approaches is most effective, including masking, vaccination, ventilation, and air filtration.”

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JOURNAL

PLoS ONE

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Ventilation during COVID-19 in a school for students with intellectual and developmental disabilities (IDD)”

ARTICLE PUBLICATION DATE

3-Apr-2024

 

JAX researchers make mice a more powerful tool to study a wide range of human diseases

A new protocol sets the stage for researchers to directly compare mouse and human cells, and readily incorporates genetic diversity into mouse-based research to more closely approximate human health conditions

JACKSON LABORATORY

 

IMAGE: 

THE NEW PROTOCOL COAXES MOUSE STEM CELLS TO DEVELOP ACROSS MULTIPLE STRAINS OF MICE, NOT JUST STRAIN 129. THIS ENABLES RESEARCHERS TO IDENTIFY WHICH STRAIN BEST RESEMEBLES CELLS IN DIFFERENT HUMAN CONDITIONS.

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CREDIT: THE JACKSON LABORATORY

In humans, the exact same mutation in a specific gene can produce widely different outcomes. It’s a bit like adding the same amount of salt to different recipes—the effect on the finished dish can be quite different, depending on the mix of other ingredients. Now, researchers at The Jackson Laboratory (JAX) have developed a powerful platform to study the reasons behind these varying mutation outcomes. The work, published today in Science Advances, not only provides new opportunities for uncovering targets for therapeutic interventions but also represents a significant step forward in addressing the critical need for studying human disease in the context of genetic diversity.

The platform, developed by JAX Professor Martin Pera, Ph.D. and Associate Research Scientist Daniel Cortes, Ph.D., and their colleagues, uses stem cells from eight different mouse strains to mimic the genetic diversity seen in humans. With the platform, they were able to investigate the effects of background genetics on the DYRK1A gene, long associated with autism, microcephaly, and intellectual disability in humans. The result: Chemically inhibiting the function of DYRK1A or knocking the gene out within the stem cells from the eight mouse strains led to markedly different effects in the growth and repair of neurons, providing molecular insights into what may confer resistance or vulnerability to the development of autism.

“If we studied one strain, we wouldn’t have seen this incredible degree of variation,” said Pera. “But by studying eight, we showed that stem cell models in a dish can accurately predict an individual’s sensitivity or resilience to disease-causing mutations, in this case an autism syndrome disorder. Careful comparison of sensitive and resilient mouse strains at the cellular level also enabled us to identify potential targets for therapeutic intervention.” 

To create the platform, Pera, Cortes and colleagues, including JAX Associate Professors Laura Reinholdt, Ph.D., and Kristen O’Connell, Ph.D., had to overcome a key obstacle. They found that only the stem cells from mouse strain 129S1/SvlmJ (129) could be coaxed into differentiating into neurons using commonly used protocols. The JAX team – and this is the innovation -- developed protocols that worked across all eight strains and, with modification, produced multiple neuron types with high efficiency.

In previous work, Pera also investigated DYRK1A in human-induced pluripotent stem cells (iPSC), derived from adult skin or blood cells that can be induced to become stem cells. These stem cells can then re-differentiate into any cells in the body given specific genetic instructions, a state known as pluripotency. The protocols developed for the mouse cell lines were effective in generating the same neuron types from multiple pluripotent human stem cell lines, validating the results obtained in the mouse cell platform. 

Further investigation revealed that one mouse strain, C57BL/6J (B6), most closely modeled the human iPSC response to low DYRK1A levels or inhibition during neural cell specification and expansion. The strains least affected were WSB/EiJ (WSB) and NZOHiLtJ (NZO). B6 and WSB also showed highly divergent responses to axonal injury. Comprehensive comparisons between strains highlighted the molecular mechanisms that define these differences, previously implicated in neurodevelopmental disorders.

Finally, Pera's team worked with Zhong-Wei Zhang, Ph.D., at JAX to study live mice to see if the B6 susceptibility observed in the mouse stem cells was reflected in a living system. Or, rather, not living, as they found that even the loss of one copy of Dyrk1a resulted in no live offspring with a B6 background, while it did not affect survival in other backgrounds, including 129. Crossing B6 with 129 mice, however, resulted in live offspring with clinical features associated with DYRK1A mutations in humans, suggesting an effective mouse model for diseases such as Alzheimer’s, Down syndrome, microcephaly, autism, and intellectual disability.

“This work illustrates the power of incorporating genetic diversity into disease models,” said Pera. “The use of stem cells in vitro allows us to directly compare mouse and humans, and to bridge results in a petri dish to those in a whole organism. The approach will have wide application in disease genetics and will enhance and accelerate precision disease modeling in the mouse.”

 

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JOURNAL

Science Advances

DOI

10.1126/sciadv.adj9305 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

An in vitro neurogenetics platform for precision disease modeling in the mouse

ARTICLE PUBLICATION DATE

3-Apr-2024

 

'Smart swarms' of tiny robots inspired by natural herd mentality

UNIVERSITY OF TEXAS AT AUSTIN

In natural ecosystems, the herd mentality plays a major role – from schools of fish, to beehives to ant colonies. This collective behavior allows the whole to exceed the sum of its parts and better respond to threats and challenges. 

This behavior inspired researchers from The University of Texas at Austin, and for more than a year they've been working on creating "smart swarms" of microscopic robots. The researchers engineered social interactions among these tiny machines so that they can act as one coordinated group, performing tasks better than they would if they were moving as individuals or at random.

"All these groups, flocks of birds, schools of fish and others, each member of the group has this natural inclination to work in concert with its neighbor, and together they are smarter, stronger and more efficient than they would be on their own," said Yuebing Zheng, associate professor in the Walker Department of Mechanical Engineering and Texas Materials Institute. "We wanted to learn more about the mechanisms that make this happen and see if we can reproduce it."

Zheng and his team first showcased these innovations in a paper published in Advanced Materials last year. But they've taken things a step further in a new paper published recently in Science Advances.

In the new paper, Zheng and his team have given these swarms a new trait called adaptive time delay. This concept allows each microrobot within the swarm to adapt its motion to changes in local surroundings. By doing this, the swarm showed a significant increase in responsivity without decreasing its robustness – the ability to quickly respond to any environment change while maintaining the integrity of the swarm.

This finding builds on a novel optical feedback system – the ability to direct these microrobots in a collective way using controllable light patterns. This system was first unveiled in the researchers’ 2023 paper –  recently chosen as an "editor's choice" by Advanced Materials – and it facilitated the development of adaptive time delay for microrobots.

The adaptive time delay strategy offers potential for scalability and integration into larger machinery. This approach could significantly enhance the operational efficiency of autonomous drone fleets. Similarly, it could enable conveys of trucks and cars to autonomously navigate extensive highway journeys in unison, with improved responsiveness and increased robustness. The same way schools of fish can communicate and follow each other, so will these machines. As a result, there's no need for any kind of central control, which takes more data and energy to operate.

"Nanorobots, on an individual basis, are vulnerable to complex environments; they struggle to navigate effectively in challenging conditions such as bloodstreams or polluted waters," said Zhihan Chen, a Ph.D. student in Zheng's lab and co-author on the new paper. "This collective motion can help them better navigate a complicated environment and reach the target efficiently and avoid obstacles or threats."

Having proven this swarm mentality in the lab setting, the next step is to introduce more obstacles. These experiments were conducted in a static liquid solution. Up next, they'll try to repeat the behavior in flowing liquid. And then they'll move to replicate it inside an organism.

Once fully developed, these smart swarms could serve as advanced drug delivery forces, able to navigate the human body and elude its defenses to bring medicine to its target. Or, they could operate like iRobot robotic vacuums, but for contaminated water, collectively cleaning every bit of an area together.

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JOURNAL

Science Advances

DOI

10.1126/sciadv.adk3914 

ARTICLE TITLE

Persistent and responsive collective motion with adaptive time delay

ARTICLE PUBLICATION DATE

3-Apr-2024

 

Better nutrition can lead to better brain health, GSA publication shows

THE GERONTOLOGICAL SOCIETY OF AMERICA

“Insights & Implications in Gerontology: The Vital Role of Nutrition in Brain Health,” a new publication from the Gerontological Society of America, explores nutritional choices that have been shown to improve cognition and decrease the risk of cognitive impairment and dementia in older adults.

Consumption of a healthful diet is a behavioral strategy that can help to prevent the development of dementia as people age, the publication says. It also reports on the roles of vitamins and minerals in nutrition and brain function and focuses on how to implement person-centered conversations about the impact of diet and nutrition on overall wellness, including brain health.

Using a person-centered approach that ties conversations about nutrition to patient goals is an effective strategy for starting conversations about diet and health, according to Kathryn Porter Starr, PhD, RDN from Duke University School of Medicine and Durham VA Medical Center, who served as one of the faculty who oversaw the publication’s development.

“Broaching the topic of diet and nutrition can be challenging. I start by asking patients what their goals are,” she said. “These goals could include physical goals such as maintaining muscle mass, cognitive goals such as preserving memory, as well as functional goals such as being able to travel or play with grandchildren. Linking information about nutrition to helping adults achieve their goals is an effective strategy for stimulating motivation to implement healthy changes.”

The Mediterranean-DASH Diet Intervention for Neurodegenerative Delay, or MIND diet, is an example of a dietary pattern that is associated with improved cognition. This dietary pattern focuses on the consumption of vegetables (especially green leafy vegetables), nuts, berries, beans, whole grains, fish, poultry, and extra virgin olive oil while limiting red meat, processed meats, butter and margarine, regular cheese, pastries and sweets, and fried foods. People who consume this dietary pattern have been found to be the equivalent of 7.5 years younger in terms of cognitive abilities. The publication includes more details about the MIND diet and other dietary patterns that support healthy nutrition.

Ideally, individuals are able to obtain all necessary nutrients from their diet. However, the risk for inadequate vitamin and mineral intake increases as people age, and some people may benefit from consumption of fortified foods and or dietary supplements to enhance their nutritional status.

“I would love for everybody to get all of their micronutrients from food,” Starr said. Unfortunately, for most older adults, it’s really challenging to do that due to physiological changes that occur with aging and certain disease states that affect absorption, so we often recommend a multivitamin.”

Other publication faculty include Rose Ann DiMaria-Ghalili, PhD, RN, FASPEN, FAAN, FGSA from Drexel University; Sareen S. Gropper, PhD, RDN, LDN from Florida Atlantic University; and Roger A. Fielding, PhD from Tufts University School of Medicine. Support for “Insights & Implications in Gerontology: The Vital Role of Nutrition in Brain Health” was provided by Haleon.

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The Gerontological Society of America (GSA) is the nation's oldest and largest interdisciplinary organization devoted to research, education, and practice in the field of aging. The principal mission of the Society — and its 5,500+ members — is to advance the study of aging and disseminate information among scientists, decision makers, and the general public. GSA’s structure includes a nonpartisan public policy institute, the National Academy on an Aging Society, and GSA is also home to the National Center to Reframe Aging and the National Coordinating Center for the Resource Centers for Minority Aging Research.

 

Dartmouth researchers map how the brain regulates emotions

Study identifies multiple emotion regulation systems, providing targets for therapy

DARTMOUTH COLLEGE

Ever want to scream during a particularly bad day, but then manage not to? Thank the human brain and how it regulates emotions, which can be critical for navigating everyday life. As we perceive events unfolding around us, the ability to be flexible and reframe a situation impacts not only how we feel, but also our behavior and decision-making.

In fact, some of the problems associated with mental health relate to individuals' inability to be flexible, such as when persistent negative thoughts make it hard to perceive a situation differently.

To help address such issues, a new Dartmouth-led study is among the first of its kind to separate activity relating to emotion generation from emotion regulation in the human brain. The findings are published in Nature Neuroscience.

"As a former biomedical engineer, it was exciting to identify some brain regions that are purely unique to regulating emotions," says lead author Ke Bo, a postdoctoral researcher in the Cognitive and Affective Neuroscience Lab (CANlab) at Dartmouth. "Our results provide new insight into how emotion regulation works by identifying targets which could have clinical applications."

For example, the systems the researchers identified could be good targets for brain stimulation to enhance the regulation of emotion.

Using computational methods, the researchers examined two independent datasets of fMRI studies obtained earlier by co-author Peter Gianaros at the University of Pittsburgh. Participants' brain activity was recorded in an fMRI scanner as they viewed images that were likely to draw a negative reaction such as a bloody scene or scary- looking animals.

The participants were then asked to recontextualize the stimulus by generating new kinds of thoughts about an image to make it less aversive, before a neutral image was presented followed by another dislikable image. 

By examining the neural activity, researchers could identify the brain areas that are more active when emotions are regulated versus when emotions are generated.

The new study reveals that emotion regulation, also known in neuroscience as "reappraisal," involves particular areas of the anterior prefrontal cortex and other higher-level cortical hierarchies whose role in emotion regulation had not previously been isolated with this level of precision. These regions are involved in other high-level cognitive functions and are important for abstract thought and long-term representations of the future.

The more people are able to activate these emotion regulation-selective brain regions, the more resilient they are to experiencing something negative without letting it affect them personally. These findings build on other research linking these areas to better mental health and the ability to resist temptations and avoid drug addiction.

The results also demonstrated that the amygdala, which is known as the threat-related brain region responsible for negative emotion and has long been considered an ancient subcortical threat center, responds to aversive experiences the same way, whether people are using their thoughts to self-regulate down-regulate negative emotion or not. "It's really the cortex that is responsible for generating people's emotional responses, by changing the way we see and attach meaning to events in our environments," says Bo. 

The researchers were also interested in identifying the neurochemicals that interact with emotion regulation systems. Neurotransmitters like dopamine and serotonin shape how networks of neurons communicate and are targets for both illicit drugs and therapeutic treatments alike. Some neurotransmitters may be important for enabling the ability to self-regulate or "down-regulate." 

The team compared the emotion regulation brain maps from the two datasets to neurotransmitter binding maps from 36 other studies. The systems involved in regulating negative emotion overlapped with particular neurotransmitter systems.  

"Our results showed that receptors for cannabinoids, opioids, and serotonin, including 5H2A, were especially rich in areas that are involved in emotion regulation," says senior author Tor Wager, the Diana L. Taylor Distinguished Professor in Neuroscience and director of the Dartmouth Brain Imaging Center at Dartmouth. "When drugs that bind to these receptors are taken, they are preferentially affecting the emotion regulation system, which raises questions about their potential for long-term effects on our capacity to self-regulate." 

Serotonin is well-known for its role in depression, as the most widely used antidepressant drugs inhibit its reuptake in synapses, which transmit signals from one neuron to another. 

5H2A is the serotonin receptor most strongly affected by another exciting new type of treatment for mental health – psychedelic drugs. The study’s findings suggest that the effects of drugs on depression and other mental health disorders may work in part by altering how we think about life events and our ability to self-regulate. This may help explain why drugs, particularly psychedelics, are likely to be ineffective without the right kind of psychological support. The study could help improve therapeutic approaches by increasing our understanding of why and how psychological and pharmaceutical approaches need to be combined into integrated treatments.

"It's important to consider these types of connections that come from basic science," says Wager. "Understanding drug effects requires understanding the brain systems involved and what they're doing at a cognitive level."

Bo (Ke.Bo@dartmouth.edu) and Wager (Tor.D.Wager@dartmouth.edu) are available for comment. CANlab members Mijin Kwon, Guarini '24 and Michael Sun, a postdoctoral researcher at Dartmouth, and Thomas Kraynak at the University of Pittsburgh also contributed to the study.

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JOURNAL

Nature Neuroscience

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

People

ARTICLE TITLE

A systems identification approach using Bayes factors to deconstruct the brain bases of emotion regulation

ARTICLE PUBLICATION DATE

22-Apr-2024