Scientists discover how nanoplastics disrupt brain energy metabolism

Trinity College Dublin

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Professor Gavin Davey in his lab in the Trinity Biomedical Sciences Institute.

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Credit: Prof. Gavin Davey, Trinity College Dublin.

Scientists from Trinity College Dublin have discovered how nanoplastics – even smaller than microplastics – disrupt energy metabolism in brain cells. Their findings may have implications for better understanding neurodegenerative diseases characterised by declining neurological or brain function, and even shed new light on issues with learning and memory.  

The study, led by Dr Gavin Davey and undergraduate Devin Seward from Trinity’s School of Biochemistry and Immunology, has revealed the specific mechanism by which these tiny nanoplastics can interfere with energy production in the brain in an animal model. The findings, recently published in the Journal of Hazardous Materials: Plastics, provide fresh insights into the potential health risks posed by environmental plastics.

Polystyrene nanoplastics (PS-NPs) are produced when larger plastics break down in the environment. These particles have been detected in multiple organs in the body, including the brain, sparking growing concerns about their possible role in neurological disease.

The Trinity team focused on mitochondria, the “powerhouses” of cells, which are critical for producing the energy needed for brain function. Mitochondrial dysfunction is a well-known feature of neurodegenerative diseases such as Parkinson’s and Alzheimer’s, as well as normal ageing.

By isolating mitochondria from brain cells, the researchers showed that exposure to PS-NPs specifically disrupted the “electron transport chain”, a simplified term for the set of protein complexes that work together to help generate cellular energy in the form of ATP. While individual mitochondrial complexes I and II were not directly impaired, electron transfer between complexes I–III and II–III, as well as the activity of complex IV, was significantly inhibited.

And although some of the concentrations of PS-NPs used in the study were higher than current estimates of human exposure the scientists found that electron transfer between complex I–III and complex II–III was potently inhibited at much lower concentrations, suggesting environmentally relevant exposures could also impair bioenergetic function over chronic timeframes.

Interestingly, the same broad effects were seen in synaptic mitochondria, which are essential for communication between brain cells. This suggests that nanoplastics could also interfere with synaptic plasticity, a process fundamental to learning and memory.

Dr Gavin Davey, who is based in the Trinity Biomedical Sciences Institute, said: “Importantly, the rise of synthetic plastics in the mid-20th century coincided with an increased global exposure to nanoplastics, so this newly discovered mitochondrial mechanism of nanoplastic-induced neurotoxicity may therefore help to explain why rates of neurodegenerative diseases have risen in recent decades, likely adding an environmental dimension to the known genetic and lifestyle risk factors.”

“Our results here show a clear mitochondrial mechanism by which nanoplastics can impair brain energy metabolism. This could therefore have major implications for how environmental pollutants contribute to neurological disease and ageing.”

The project was originally conceived by Devin in 2023, during his time as a Neuroscience degree student. Supported by the Laidlaw Foundation via a Laidlaw Undergraduate Research and Leadership scholarship, Devin carried out the work in Dr Davey’s laboratory in the School of Biochemistry and Immunology.

Devin said: “Coming up with this idea and then being able to develop it in Dr Davey’s lab with the support of the Laidlaw Foundation has been an incredible experience. It has given me the opportunity to contribute to important research on environmental health at an early stage in my career, and it’s exciting to see our findings published.”

The study underscores the urgent need to better understand the health consequences of plastic pollution, while also highlighting the impact of undergraduate-led research supported by the Laidlaw Foundation at Trinity.

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DOI

10.1016/j.hazmp.2025.100003 

Method of Research

Meta-analysis

 

Mental health benefits of retirement not evenly shared, study says

The impact of retirement on mental health depends on income level, the nature of the job left behind, and the age at which people leave the workforce, a study suggests.

University of Edinburgh

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Mental health benefits of retirement not evenly shared, study says

The impact of retirement on mental health depends on income level, the nature of the job left behind, and the age at which people leave the workforce, a study suggests.

Researchers found that although retirees’ wellbeing generally improved once they finished work, some groups were at risk of dips in mental health.

People on an average income who had a physically demanding job before they retired and those on a high-income who retire at a later age are at risk of feeling low during the retirement process, experts say.

Retirees who are female, unmarried and on a low-income at the time of leaving work also reported significantly lower levels of mental health, the study found.

Researchers say the report could help guide targeted policy interventions and shows that people with a low income are a group at risk and require greater policy attention.

The study is among the first to assess the three phases of retirement – before, after and during leaving work – and to measure the mental health outcomes associated with factors including pre-retirement job demands and age

A University of Edinburgh team assessed a dataset of 1583 people from the Netherlands, where participants completed surveys on health, work, education, family and personality from 2007 to 2023.

Data was included from those who reported being retired and not undertaking any paid work. The average retirement age in the sample was 66 to 67 years.

Statistical models were used to assess people’s mental health five and a half years before and after retirement, and upon retirement.

Mental health was measured by the Mental Health Inventory, which records psychological well-being, depressive symptoms and anxiety symptoms.

The researchers found participants with a low income – earning below the minimum wage – reported the lowest levels of mental health during retirement. Although their mental health generally improved, there was a decline after an initial post-work ‘honeymoon’ phase, with dips emerging around two and a half years after retiring.

For retirees with an average income there was a substantial improvement in mental health before retirement, followed by a relatively modest increase.

Within the average income group, those who held more physically demanding jobs tended to report lower overall mental health throughout the retirement process.

Retirees with high-income showed no change in mental health before and after leaving work, but reported a significant sudden increase upon retirement. Those who retired later showed a slower improvement in mental health during the retirement year.

The study took into account other factors such as education, marital status, and retirement age.

Xuefei Li, of the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences, who led the study, said: “This study identified distinct mental health trajectories across different income groups. We can assume that people's immediate health changes at the year they retire and longer-term health changes are different. Understanding these phases sheds light on the adjustment processes that people undergo when faced with the internal and external challenges.”

Professor Aja Murray, of the University of Edinburgh’s School of Philosophy, Psychology and Language Sciences, said: “All income groups showed a general improvement in mental health during the transition to retirement, yet there were multiple phases of development where mental health can take a dip. During these vulnerable times people may benefit from targeted support.”

Future studies could assess the impact of voluntary retirement to provide insights on the effect of personal choice on leaving work, researchers say.

The study is published in SSM - Mental Health. Link to study: Mental health trajectories surrounding retirement: A longitudinal perspective - ScienceDirect

The work was funded by the Wellcome Trust.  

The study used data from 17 waves of Longitudinal Internet studies for the Social Sciences (LISS) panel administered by Centerdata at Tilburg University in the Netherlands.

For further information, please contact: Joanne Morrison, Press and PR Office, joanne.morrison@ed.ac.uk

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Journal

SSM - Mental Health

DOI

10.1016/j.ssmmh.2025.100470 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Mental health trajectories surrounding retirement: A longitudinal perspective

Article Publication Date

15-Sep-2025

GIMME SLACK!

 

Bedlam Explains the 1% vs. The 99%

The movie "Bedlam" (starring Boris Karloff, Anna Lee and Billy House) is about the treatment of patients at an 18th century insane asylum. The argument in the clip can easily double for the argument between the 1% and the 99% with a little 47% thrown in for good measure.

 

Better quality care reduces fear and coercion in mental health units

Respect for the patient’s privacy and dignity

University of Barcelona

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What makes an admission to a mental health unit a more or less traumatic experience, and what role do nurses play in this experience? A study recently published in the Journal of Clinical Nursing focuses on a question that is as sensitive as it is little explored: the perception of quality of care as a factor that can make a big difference in mental health care.

When healthcare is experienced as dignified, safe and collaborative, the feeling of having been coerced and humiliated decreases significantly, according to the conclusions of the study conducted by the NURSEARCH group of the Faculty of Nursing of the University of Barcelona. The study, which analysed the experience of 255 people admitted to twelve acute mental health units throughout Spain, is part of the project Therapeutic Space Reserved (RTS_MHNursing_Spain).

It is led by Professor Antonio R. Moreno Poyato, from the UB’s Faculty of Nursing, and it is funded by the Carlos III Health Institute and the Official College of Nurses of Barcelona (COIB). The study data were collected just before patients left the hospital, and both the perceived quality of care and the subjective experience of coercion, humiliation and fear were assessed.

Respect for the patient’s privacy and dignity

In mental health care, coercion is not always physical. It often appears as a lack of information, imposed decisions or the absence of intimate spaces to express oneself without fear. This study confirms what many professionals and people have long sensed: the way in which care is provided matters a lot.

The study highlights that aspects such as privacy, security, emotional support and discharge planning are key factors. Among all the factors, respect for privacy and dignity — what the study questionnaire describes as “protected environment” — has the greatest impact on reducing the experience of coercion and humiliation. “They also emphasize active participation in clinical decisions and discharge preparation, areas in which nurses play a key role when creating therapeutic links and ensuring person-centred care,” says Professor Antonio R. Moreno Poyato.

The findings support recommendations from bodies such as the World Health Organisation and the World Psychiatric Association to move towards person-centred models of care based on human rights, participation and recovery.

The UB study offers a specific tool for this change: it demonstrates with data that improving the perceived quality of care has a real impact on the experience of hospitalized people. “Through their daily proximity, nurses can facilitate safe spaces, foster trust and promote care that is free from coercion. This change does not always involve more resources, but rather a change in outlook and priorities: caring with respect, guaranteeing intimate spaces, listening actively and offering an emotionally safe environment”, concludes Antonio R. Moreno Poyato.
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Journal

Journal of Clinical Nursing

DOI

10.1111/jocn.70048 

Method of Research

Observational study

Subject of Research

People

Article Title

Examining the Association Between Perceived Quality of Care and Experienced Coercion Among Patients in Acute Mental Health Units in Spain: A National Cross-Sectional Study

 

You’ve never seen corn like this before

Cold Spring Harbor Laboratory

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A thin section of a maize ear at a very early stage of development (about 3 millimeters long). Each color represents the expression of a different gene in stem cells and associated cells.

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Credit: Jackson lab/CSHL

Plant stem cells are crucial for the world’s food supply, animal feed, and fuel production. They lay the foundation for how plants grow. Yet, much about these mysterious building blocks remains unknown. Previous analyses have failed to locate many of the important genes that regulate how these cells function.

Now, for the first time, Cold Spring Harbor Laboratory (CSHL) plant biologists have mapped two known stem cell regulators across thousands of maize and Arabidopsis shoot cells. Their research also uncovered new stem cell regulators in both species and linked some to size variations in maize. This method for recovering rare stem cells could be used across the plant kingdom. CSHL Professor David Jackson explains: “Ideally, we would like to know how to make a stem cell. It would enable us to regenerate plants better. It would allow us to understand plant diversity. One thing people are very excited about is breeding new crops that are more resilient or more productive. We don’t yet have a full list of regulators—the genes we need to do that.”

Jackson and his colleagues first focused on two well-known stem cell regulators called CLAVATA3 and WUSCHEL. A former postdoc in Jackson’s lab, Xiaosa Xu, delicately dissected a small piece of maize and Arabidopsis shoots containing stem cells. Then, the team used a “microfluidics” machine to separate each cell, convert its RNA into DNA, and label it with a tag that identifies which cell it came from.

The process, called single-cell RNA sequencing, allows researchers to see how genes are expressed in thousands of cells at once. “The great thing is that you have this atlas of gene expression,” Jackson says. “When we publish that, the whole community can use it. Other people interested in maize or Arabidopsis stem cells don’t have to repeat the experiment. They will be able to use our data.”

Single-cell RNA sequencing allowed the team to recover about 5,000 CLAVATA3 and 1,000 WUSCHEL-expressing cells. Next, they identified hundreds of genes that were preferentially expressed in both maize and Arabidopsis stem cells, suggesting they may be evolutionarily important across many plant species. From there, they were able to link certain stem cell regulators to productivity in maize. Such links could someday help breeders select specific strains for food, animal feed, or fuel production.

“It’s foundational knowledge that could guide research for the next decade,” Jackson says. “It can be used not only by developmental biologists, but physiologists, who think about how corn ears grow and how to improve productivity, and then breeders.”

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Journal

Developmental Cell

DOI

10.1016/j.devcel.2025.07.024 

Article Title

Large-scale single-cell profiling of stem cells identifies redundant regulators of shoot development and yield trait variation

 

When does melting ice capsize? New research unearths several mechanisms

Findings offer innovative ways to improve weather forecasting, measure climate-change impacts

New York University

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The pentagon-like shape ice takes while melting and capsizing multiple times.

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Credit: New York University’s Applied Mathematics Laboratory

Rising temperatures of the world’s oceans threaten to accelerate the melting and splintering of glaciers—thereby potentially increasing the number of icebergs and, with it, the need to better understand more about their movement and impact. Through a series of experiments, a team of scientists has pinpointed some of the factors that cause icebergs to capsize, offering insights into how climate change may affect Earth’s waters. 

“Our study contributes fundamental knowledge about ice physics, which is a vital factor in the health of our planet and which needs to be understood to improve climate modeling and weather forecasting,” explains Leif Ristroph, an associate professor at New York University’s Courant Institute of Mathematical Sciences and the senior author of the paper, which appears in the journal Physical Review Fluids. “These results show how iceberg melting and capsizing are related in complicated ways. This information is crucial as ice melting can be considered the ‘canary in the coalmine’: the earliest warning of when the Earth is warming or otherwise out of its usual balance.” 

The researchers, who also included NYU’s Bobae Johnson, Zihan Zhang, and Alison Kim as well as the Flatiron Institute’s Scott Weady, conducted a series of experiments in the university’s Applied Mathematics Laboratory that replicated floating icebergs. 

To do so, they prepared ice blocks in the form of long cylinders—eliminating bubbles that would complicate the conditions—and placed them in a tank of room-temperature fresh water, which has proven to be an effective medium to gauge ice melt in past studies. The scientists then used cameras to capture the speed and movement of the model iceberg’s melting and capsizing.  

“We found that melting gradually reshapes the ice, which then abruptly rotates or capsizes before settling into a new orientation,” explains Ristroph. “This process repeats over and over. We typically see about 10 to 15 capsize events during the 30 minutes it takes the ice to completely melt away.” 

During this process, the shape of the ice changes significantly, developing edges and corners to eventually resemble a pentagon—an unexpected outcome. The transformation is captured in this video of the experiments.

“This came as a total surprise, so we worked to explain the observations by developing a mathematical model that could account for how melting changes the shape of ice and how the evolving new shape can induce the ice to capsize,” says Ristroph. 

The mathematical model, developed by drawing from the experimental data, included the effects of the weight and buoyancy forces on the ice as well as the hydrodynamic forces due to its motion in the water—and illuminated the various factors driving shape change and capsizing.

This video from the experiments shows the flows and temperature differences of the water beneath the ice.

“We learned that melting primarily happens along the wetted surface of the ice below the waterline while the ‘tip’ out of the water is almost unaffected, which eventually leaves the ice top heavy so that it loses gravitational stability in the water and rotates over,” recounts Ristroph. “Surprisingly, it tends to rotate through a special angle corresponding to one-fifth of a complete revolution—and this relates to why the shape eventually has five sides.”

The research was supported by a grant from the National Science Foundation (DMS-2206573).

Ice forming as pentagon [VIDEO] 

The video depicts how ice melts and then repeatedly capsizes while transforming from the shape of a cylinder into a pentagon before dissipating.

Ice melting below surface [VIDEO] 

This video depicts the flow of water beneath the surface of a melting model iceberg.

The flow of water beneath the surface of melting ice.

Credit

New York University's Applied Mathematics Laboratory.

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Journal

Physical Review Fluids

DOI

10.1103/rc7r-h66q 

Method of Research

Experimental study

Article Title

Shape evolution and capsize dynamics of melting ice

Article Publication Date

12-Sep-2025