Smarter memory: next-generation RAM with reduced energy consumption

Researchers from Osaka University introduced an innovative technology to lower power consumption for modern memory devices

Osaka University

 

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Schematic of the interfacial multiferroic structure.

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Credit: T. Usami

Osaka, Japan – Numerous memory types for computing devices have emerged in recent years, aiming to overcome the limitations imposed by traditional random access memory (RAM). Magnetoresistive RAM (MRAM) is one such memory type which offers several advantages over conventional RAM, including its non-volatility, high speed, increased storage capacity and enhanced endurance. Although remarkable improvements have been made to MRAM devices, reducing energy consumption during data writing remains a critical challenge.

A study recently published in Advanced Science by researchers from Osaka University proposes a new technology for MRAM devices with lower-energy data writing. The proposed technology enables an electric-field-based writing scheme with reduced energy consumption compared to the present current-based approach, potentially providing an alternative to traditional RAM.

Conventional dynamic RAM (DRAM) devices have basic storage units consisting of transistors and capacitors. However, the stored data is volatile, meaning that energy input is required to retain the data. In contrast, MRAM uses magnetic states, such as the orientation of magnetization, to write and store data, enabling non-volatile data storage.

“As MRAM devices rely on a non-volatile magnetization state rather than a volatile charge state in capacitors, they are a promising alternative to DRAM in terms of their low power consumption in the standby state,” explains Takamasa Usami, lead author of the study.

The present MRAM devices generally require an electric current to switch the magnetization vectors of magnetic tunnel junctions, analogous to switching capacitor’s charge states in a DRAM device. However, a large electric current is needed to switch the magnetization vectors during the writing process. This results in inevitable Joule heating, leading to energy consumption.

To address the problem, the researchers have developed a new component for electric field controlling of MRAM devices. The key technology is a multiferroic heterostructure with magnetization vectors that can be switched by an electric field (Fig. 1). The response of the heterostructure to an electric field is basically characterized in terms of the converse magnetoelectric (CME) coupling coefficient; larger values indicate a stronger magnetization response.

The researchers previously reported a multiferroic heterostructure with a large CME coupling coefficient over 10-5 s/m. However, structural fluctuations in parts of the ferromagnetic layer (Co2FeSi) made it challenging to achieve the desired magnetic anisotropy, hindering reliable electric-field operation. To improve the stability of this configuration, the researchers developed a new technology for an insertion of an ultra-thin vanadium layer between the ferromagnetic and piezoelectric layers. As shown in Fig. 2, a clear interface was achieved by inserting the vanadium layer, leading to the reliable control of the magnetic anisotropy in the Co2FeSi layer. Also, the CME effect reached a value larger than that achieved with similar devices that did not include a vanadium layer.

The researchers also demonstrated that two different magnetic state can be reliably realized at zero electric field by changing the sweeping operation of the electric field. This means a non-volatile binary state can be intentionally achieved at zero electric field.

“Through precise control of the multiferroic heterostructures, two key requirements for implementing practical magnetoelectric (ME)-MRAM devices are satisfied, namely a non-volatile binary state with zero electric field, and a giant CME effect,” says Kohei Hamaya, senior author.

This research in spintronic devices could eventually be implemented on practical MRAM devices, enabling manufacturers to develop ME-MRAM, which is a low-power writing technology for a wide range of applications requiring persistent and safe memory.

Atomic image of the ferromagnetic Co2FeSi layer/atomic layer/piezoelectric layer interface. The structure on the left uses an Fe atomic layer, whereas the V layer, shown on the right, is clear, promoting the crystal orientation of the ferromagnetic Co2FeSi layer above.

Credit

T. Usami

The article “Artificial control of giant converse magnetoelectric effect in spintronic multiferroic heterostructure,” was published in Advanced Science at DOI: https://doi.org/10.1002/advs.202413566

About Osaka University
Osaka University was founded in 1931 as one of the seven imperial universities of Japan and is now one of Japan's leading comprehensive universities with a broad disciplinary spectrum. This strength is coupled with a singular drive for innovation that extends throughout the scientific process, from fundamental research to the creation of applied technology with positive economic impacts. Its commitment to innovation has been recognized in Japan and around the world. Now, Osaka University is leveraging its role as a Designated National University Corporation selected by the Ministry of Education, Culture, Sports, Science and Technology to contribute to innovation for human welfare, sustainable development of society, and social transformation.
Website: https://resou.osaka-u.ac.jp/en

 

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Journal

Advanced Science

DOI

10.1002/advs.202413566 

Article Title

Artificial control of giant converse magnetoelectric effect in spintronic multiferroic heterostructure

 

Sex differences in brain structure present at birth

University of Cambridge

Sex differences in brain structure are present from birth, research from the Autism Research Centre at the University of Cambridge has shown.

While male brains tended to be greater in volume than female brains, when adjusted for total brain volume, female infants on average had significantly more grey matter, while male infants on average had significantly more white matter in their brains.

Grey matter is made up of neuron cell bodies and dendrites and is responsible for processing and interpreting information, such as sensation, perception, learning, speech, and cognition.  White matter is made up of axons, which are long nerve fibres that connect neurons together from different parts of the brain. 

Yumnah Khan, a PhD student at the Autism Research Centre, who led the study, said: “Our study settles an age-old question of whether male and female brains differ at birth. We know there are differences in the brains of older children and adults, but our findings show that they are already present in the earliest days of life.

“Because these sex differences are evident so soon after birth, they might in part reflect biological sex differences during prenatal brain development, which then interact with environmental experiences over time to shape further sex differences in the brain.”

One problem that has plagued past research in this area is sample size. The Cambridge team tackled this by analysing data from the Developing Human Connectome Project, where infants receive an MRI brain scan soon after birth. Having over 500 newborn babies in the study means that, statistically, the sample is ideal for detecting sex differences if they are present.

A second problem is whether any observed sex differences could be due to other factors, such as differences in body size.  The Cambridge team found that, on average, male infants had significantly larger brain volumes than did females, and this was true even after sex differences in birth weight were taken into account.

After taking this difference in total brain volume into account, at a regional level, females on average showed larger volumes in grey matter areas related to memory and emotional regulation, while males on average had larger volumes in grey matter areas involved in sensory processing and motor control.

The findings of the study, the largest to date to investigate this question, are published in the journal Biology of Sex Differences.

Dr Alex Tsompanidis who supervised the study, said: “This is the largest such study to date, and we took additional factors into account, such as birth weight, to ensure that these differences are specific to the brain and not due to general size differences between the sexes.

“To understand why males and females show differences in their relative grey and white matter volume, we are now studying the conditions of the prenatal environment, using population birth records, as well as in vitro cellular models of the developing brain. This will help us compare the progression of male and female pregnancies and determine if specific biological factors, such as hormones or the placenta, contribute to the differences we see in the brain.”

The researchers stress that the differences between males and females are average differences.

Dr Carrie Allison, Deputy Director of the Autism Research Centre, said: “The differences we see do not apply to all males or all females, but are only seen when you compare groups of males and females together. There is a lot a variation within, and a lot of overlap between, each group.”  

Professor Simon Baron-Cohen, Director of the Autism Research Centre, added: “These differences do not imply the brains of males and females are better or worse. It’s just one example of neurodiversity. This research may be helpful in understanding other kinds of neurodiversity, such as the brain in children who are later diagnosed as autistic, since this is diagnosed more often in males.”

The research was funded by Cambridge University Development and Research, Trinity College, Cambridge, the Cambridge Trust, and the Simons Foundation Autism Research Initiative.

Reference

Khan, Y.T., Tsompanidis, A., Radecki, M.A. et al. Sex differences in human brain structure at birth. Biol Sex Differ; 17 Oct 2024; DOI: 10.1186/s13293-024-00657-5

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Journal

Biology of Sex Differences

DOI

10.1186/s13293-024-00657-5 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Sex differences in human brain structure at birth

 

Groundbreaking discoveries in the fight against Huntington's disease

The University of Bergen

 

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Visualization of protein clumps associated with Huntington's disease, produced by combining simulations and several complementary types of experiments

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Credit: Markus Miettinen, UiB/CBU.

University of Bergen researcher Markus Miettinen is among the first scientists to provide a detailed description of protein clumps associated with Huntington's disease. The findings, which could pave the way for new diagnostic tools and treatments, were recently presented in an article in Nature Communications.

“There is hope that our research can lead to treatments for Huntington's disease. Understanding the structure of the protein clumps is a crucial piece of the puzzle in understanding how these proteins can cause disease. Our new molecular findings are essential for further developing diagnostic tools and imaging techniques to detect and monitor disease proteins in patients,” says chemist Markus Miettinen from the University of Bergen, Norway and the Computational Biology Unit.

Together with an international team of researchers – including Mahdi Bagherpoor Helabad from the Max Planck Institute of Colloids and Interfaces, Irina Matlahov, Greeshma Jain, and Patrick C. A. van der Wel from the University of Groningen, Raj Kumar and Markus Weingarth from the University of Utrecht, and Jan O. Daldrop from Freie Universität Berlin – he has combined advanced computer simulations and experimental methods to achieve these groundbreaking results.

The findings are presented in the article «Integrative determination of atomic structure of mutant huntingtin exon1fibrils implicated in Huntington disease», published online in Nature Communications on December 30, 2024.

Revealing Protein Clumps with a Pioneering Method

Huntington's disease is a fatal disease caused by an inherited mutation that makes a protein form unnatural clumps. These protein clumps play a role in disease development, but until now, we have lacked a good understanding of what they look like at atomic level.

By combining various computer- and experiment-based approaches, the researchers have now managed to visualize the first detailed picture of these disease-related clumps. The methods used are an exciting example of the interdisciplinary approach that represents the future of structural biology – and pave the way for the development of diagnostic tools and treatments that are urgently needed.

“We use advanced computer simulations to mimic the behavior of these molecules as realistically as possible. Our work bridges the gap between simulations and experiments, providing insights into data that are otherwise difficult to interpret. Beyond the new insights into Huntington's disease, we have developed tools that make molecular simulations more accessible to researchers worldwide,” says Miettinen.

This type of protein clumping is not only known in connection with Huntington's disease but also in Alzheimer's, Parkinson's, and other diseases. The structure of the clumps in Huntington’s disease is remarkably different from other disease proteins, opening up several new scientific questions about their properties and formation mechanisms.

Facts, Advice, and Insights

• Huntington's disease is an inherited neurodegenerative disease.
• Protein clumps play a central role in disease development.
• New molecular findings can contribute to the development of diagnostic tools and treatments.

Funding

The research project is largely funded by foundations supporting Huntington's disease and made possible by support from families affected by the disease and the general public.

“It is exciting to see their recognition of the importance of research into the fundamental causes of the disease,” says Miettinen.

About Computational Biology Unit

The Computational Biology Unit is an interdisciplinary collaboration between two faculties and five departments at the University of Bergen – the Faculty of Mathematics and Natural Sciences (Department of Informatics, Department of Chemistry, and Department of Biological Sciences) and the Faculty of Medicine (Department of Biomedicine and Department of Clinical Science). The center hosts research and education in bioinformatics and computational biology and has been awarded approximately 17 million Euros from the University of Bergen, Haukeland University Hospital, and the Trond Mohn Research Foundation for the period 2017-2026.

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Journal

Nature Communications

DOI

10.1038/s41467-024-55062-8 

Article Title

Integrative determination of atomic structure of mutant huntingtin exon 1 fibrils implicated in Huntington disease

 PSEUDOSCIENCE 

Science behind genetic testing for identifying risk of opioid misuse remains unproven

A new report from researchers at the University of Pennsylvania Perelman School of Medicine and Crescenz VA Medical Center evaluated a genetic test for opioid use disorder that recently received pre-marketing approval by the FDA, finding that the genes 

Peer-Reviewed Publication

University of Pennsylvania School of Medicine

PHILADELPHIA—Opioid misuse and specifically opioid use disorder (OUD), continues to represent a significant U.S. public health threat, with more than 6 million Americans aged 12 and older meeting the criteria for OUD in 2022. Efforts to ease the crisis have included the development of genetic testing to identify individuals most at risk for OUD. New research, out today in JAMA Network Open, questions the usefulness of 15 genetic variants from an algorithm meant to predict OUD risk that was recently granted pre-marketing approval by the Food and Drug Administration. It found that the testing could lead to both false positive and false negative results.

The study was led by Christal Davis, PhD, a postdoctoral fellow at the Philadelphia-based Crescenz VA Medical Center and Henry Kranzler, MD, a professor of Psychiatry and the director of the Center for Studies of Addiction.

“These findings underscore the need for more robust and complete data, particularly given the complex nature of psychiatric conditions, including OUD,” Kranzler said. “The potential harms deriving from a faulty genetic test for OUD include both false negatives and false positives.”

For example, if the test wrongly identifies patients as being at low risk of OUD, they may have a false sense of security taking opioids, and providers may prescribe opioids to those who could become addicted. Patients who falsely test for a high risk of OUD may be denied an effective form of pain relief, in addition to potentially facing stigma.  

The case-control study drew upon health record data from more than 450,000 participants with opioid exposure in the Million Veteran Program (MVP), including more than 33,000 individuals with OUD. It showed that the 15 single nucleotide variants (SNVs) purported to predict OUD risk were not useful in identifying OUD, as they had high rates of both false negative and false positive results. With 47 of 100 cases misidentified, the results are equivalent to a coin toss.

A related letter by a group of psychiatric geneticists, including Drs. Davis and Kranzler, was recently published in Lancet Psychiatry. It outlines key factors that regulators should consider for this and future proposed genetic testing for OUD and other psychiatric disorders. These considerations include the significant environmental contribution to psychiatric disorders and how differences in genetic ancestry and an individual’s life experiences need to be considered when predicting risk for OUD or other psychiatric disorders.

This study was supported principally by the Million Veteran Program, a research initiative of the U.S. Department of Veterans Affairs that studies how genes, lifestyle, military experiences, and other exposures impact health and wellness in veterans, with grant support provided by the awards I01 BX003341 and IK2 CX002336 from the VA; the VISN 4 Mental Illness Research, Education and Clinical Center; grant K01 AA028292 from the National Institute on Alcohol Abuse and Alcoholism, and grant P30 DA046345 from the National Institute on Drug Abuse.

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Penn Medicine is one of the world’s leading academic medical centers, dedicated to the related missions of medical education, biomedical research, excellence in patient care, and community service. The organization consists of the University of Pennsylvania Health System and Penn’s Raymond and Ruth Perelman School of Medicine, founded in 1765 as the nation’s first medical school.

The Perelman School of Medicine is consistently among the nation's top recipients of funding from the National Institutes of Health, with $550 million awarded in the 2022 fiscal year. Home to a proud history of “firsts” in medicine, Penn Medicine teams have pioneered discoveries and innovations that have shaped modern medicine, including recent breakthroughs such as CAR T cell therapy for cancer and the mRNA technology used in COVID-19 vaccines.

The University of Pennsylvania Health System’s patient care facilities stretch from the Susquehanna River in Pennsylvania to the New Jersey shore. These include the Hospital of the University of Pennsylvania, Penn Presbyterian Medical Center, Chester County Hospital, Lancaster General Health, Penn Medicine Princeton Health, and Pennsylvania Hospital—the nation’s first hospital, founded in 1751. Additional facilities and enterprises include GSPP Rehabilitation, Penn Medicine at Home, Lancaster Behavioral Health Hospital, and Princeton House Behavioral Health, among others.

Penn Medicine is an $11.1 billion enterprise powered by more than 49,000 talented faculty and staff.

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Journal

JAMA Network Open

Article Title

Utility of Candidate Genes From an Algorithm Designed to Predict Genetic Risk for Opioid Use Disorder

Article Publication Date

9-Jan-2025

 

Two-in-one root armor protects plants from environmental stressors and fights climate change

Salk’s new single-cell analysis provides detailed first look at plant roots’ protective outer layer and carbon-capturing cells

Salk Institute

 

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Section of a plant root showcasing the periderm and its carbon-capturing phellem cells.

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Credit: Salk Institute

LA JOLLA (January 9, 2025)—Plants may burrow into the ground and stretch toward the sun, but they’re ultimately stuck where they sprout—at the mercy of environmental threats like temperature, drought, and microbial infection. To compensate for their inability to up and move when danger strikes, many plants have evolved ways to protect themselves by altering their physiology, such as building armor around parts of their body and roots called the periderm. However, since many plant biologists who study tissue development look at young plants, later-in-life periderm development has remained relatively unexplored.

Salk Institute researchers have debuted the first comprehensive gene expression atlas of the plant periderm at the single-cell level. The atlas provides new information about the different kinds of cells that make up the periderm and which specific genes and biological processes control their development. This includes important insights into phellem cells, which are rich in suberin—a molecule that helps capture and store excess carbon from the atmosphere for a long time. Scientists can now use this information to stimulate growth of the protective periderm in plants facing environmental stress due to climate change. They can also potentially boost phellem cell growth genes to produce plants with enhanced carbon-capturing and storing abilities—a central goal of Salk’s Harnessing Plants Initiative.

The findings were published in Developmental Cell on January 9, 2025.

“Plants play a crucial role in capturing carbon from the atmosphere and storing it in the soil,” says Professor Wolfgang Busch, senior author of the study, director of the Harnessing Plants Initiative, and Hess Chair in Plant Science at Salk. “The protective outer layer of plant roots, called the periderm, is made up of many cells that can store carbon in a form that will be very durable. By creating a detailed map of how these root cells form and mature, we can better understand and potentially encourage this process to help plants hold on to more carbon in highly durable forms. In doing so, we can create more resilient plants with hardier roots that also help us fight climate change.”

When a plant first takes root, it dedicates itself to primary growth, focusing on the length of new roots. With maturity comes secondary growth, shifting the focus to thickening existing roots and creating periderm armor. This protective periderm contains phellem, phellogen, and phelloderm cells, each with distinct responsibilities and genetic profiles that had yet to be fully described in previous studies. 

Of these various periderm cells, the team was most interested in phellem cells because of their high suberin content. Suberin is central to Salk’s Harnessing Plants Initiative, in which scientists optimize plants to serve as a natural and sustainable method of carbon sequestration. Unfortunately, carbon stored in leaves and stems can degrade quickly and become easily re-released into the atmosphere. In contrast, the suberin in a plant’s roots can hold carbon deep in the soil for long stretches of time. Suberin has also been shown to make plants more resistant to root rot, indicating that it serves a protective purpose in addition to carbon storage.

Previous periderm studies consisted of bulk analyses that, despite providing valuable insights, were not able to capture cell type specificity. To correct this, the Salk team applied modern single-cell sequencing techniques that could capture the distinct genetic profiles of each periderm cell type. They also tracked how gene expression changed as each cell type developed in the roots of Arabidopsis thaliana—a flowering weed in the mustard family commonly used in plant research.

"Collecting this level of detail in mature plants across time has never been achieved before,” says first author Charlotte Miller, a research scientist in Busch’s lab. “Other studies grind up entire roots and study them in bulk, but single-cell analysis allowed us to understand the genetic development of each individual cell type in the periderm. This means we can be far more precise and efficient in engineering robust, resilient, climate change-fighting plants.”

The researchers’ single-cell time-course sequencing revealed that phellem cell development can be dissected into multiple genetically distinct but interconnected phases. This stepwise development was marked by key genes like MYB67, which the team discovered was playing a large role in regulating the development process.

By piecing together the cells’ genetic profiles at different periods in their development, the team hopes to eventually determine a gene or set of genes that could be used to encourage plants to make more phellem cells, contain more suberin, and capture more durable carbon.

The periderm atlas also yielded important insights into other non-phellem cells. This data will help clarify the transitional stages in periderm development, like how phellogen cells give rise to phellem cells. Miller is particularly excited to continue studying these phellogen cells, noting that their stem-cell-like ability to differentiate into other cell types so late into the plant’s development is surprising.

As for Busch, he looks forward to seeing how suberin-containing cells plug up holes made by new lateral root growth—a destructive process where new roots break through the plants’ skin. These responsive, suberin-rich cells may not be a part of the periderm, but knowing more about the periderm cell types and suberin content may aid in future understanding of this root creation process wherein root systems branch out extensively while avoiding infection.

“Our work not only advances plant science but also opens the door to creating more robust crops and enhancing carbon sequestration through plant roots, providing solutions to both agricultural and climate challenges, which is a key goal of Salk’s Harnessing Plants Initiative,” says Busch.

Other authors include Sean Jarrell-Hurtado, Manisha Haag, Y. Sara Ye, Mathew Simenc, Paloma Alvarez-Maldonado, Sara Behnami, Ling Zhang, Joseph Swift, Ashot Papikian, Jingting Yu, Kelly Colt, Joseph Ecker, Todd Michael, and Julie Law of Salk.

The work was supported by the Bezos Earth Fund, Hess Corporation, and TED Audacious Project.

About the Salk Institute for Biological Studies:

Unlocking the secrets of life itself is the driving force behind the Salk Institute. Our team of world-class, award-winning scientists pushes the boundaries of knowledge in areas such as neuroscience, cancer research, aging, immunobiology, plant biology, computational biology, and more. Founded by Jonas Salk, developer of the first safe and effective polio vaccine, the Institute is an independent, nonprofit research organization and architectural landmark: small by choice, intimate by nature, and fearless in the face of any challenge. Learn more at www.salk.edu.

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Journal

Developmental Cell

Article Title

A single nuclei transcriptome census of the Arabidopsis maturing root identifies that MYB67 controls phellem cell maturation

Article Publication Date

9-Jan-2025

 

The extreme teeth of sabre-toothed predators were ‘optimal’ for biting into prey, new study reveals

University of Bristol

 

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Graphic showing functional optimality drives repeated evolution of extreme sabertooth forms

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Credit: Tahlia Pollock

Sabre-toothed predators – best know from the infamous Smilodon – evolved multiple times across different mammal groups. A new study, published today in Current Biology reveals why: these teeth were ‘functionally optimal’ and highly effective at puncturing prey.

The study, led by scientists at the University of Bristol in collaboration with Monash University shows that long, sharp blade-like teeth gave sabre-tooth’s a real advantage as specialised weapons for capturing prey.

The findings help explain why sabre-teeth evolved so many times (at least five independent times in mammals) and also provides a possible explanation for their eventual demise. Their increasing specialisation may have acted as an ‘evolutionary ratchet’, making them highly effective hunters – but also more vulnerable to extinction when ecosystems changed and their prey became scarce.

The team, set out to test whether sabre-tooth shape was an optimal balance between the two competing needs: sharp and slender enough to effectively puncture prey and blunt and robust enough to resist breaking. Using 3D-printed steel tooth replicas in a series of biting experiments and advanced computer simulations, they analysed the shape and performance of 95 different carnivorous mammal teeth, including 25 sabre-toothed species.

Lead author Dr Tahlia Pollock, part of the Palaeobiology Research Group in Bristol’s School of Earth Sciences, explained: “Our study helps us better understand how extreme adaptations evolve – not just in sabre-toothed predators but across nature.

“By combining biomechanics and evolutionary theory, we can uncover how natural selection shapes animals to perform specific tasks.”

Another key finding challenges the traditional idea that sabre-toothed predators fell into just two categories: ‘dirk-toothed' and 'scimitar-toothed’. Instead, the research uncovered a spectrum of sabre-tooth shapes, from the long, curved teeth of Barbourofelis fricki to the straighter, more robust teeth of Dinofelis barlowi. This supports a growing body of research suggesting a greater diversity of hunting strategies among these predators than previously thought.

Looking ahead, the team plans to expand their analysis to include all tooth types, aiming to uncover the biomechanical trade-offs that shaped the evolution of diverse dental structures across the animal kingdom.

“The findings not only deepen our understanding of sabre-toothed predators but also have broader implications for evolutionary biology and biomechanics,” added Professor Alistair Evans, from the School of Biological Sciences at Monash University. “Insights from this research could even help inform bioinspired designs in engineering.”

Paper:

‘Functional optimality underpins the repeated evolution of the extreme ‘sabre-tooth’ morphology’ by Tahlia Pollock et al in Current Biology.

 

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Journal

Current Biology

Method of Research

Computational simulation/modeling

Subject of Research

Animals

Article Title

Functional optimality underpins the repeated evolution of the extreme ‘sabre-tooth’ morphology

Article Publication Date

9-Jan-2025

 

Scientists show how sleep deprived brain permits intrusive thoughts

University of York

A new study has shown that sleep deprivation can inhibit the brain’s ability to suppress unwanted memories and intrusive thoughts.

Scientists at the University of York, in collaboration with the University of East Anglia, have shown that sleep deprivation interferes with the ability of the prefrontal area of the brain to restrict the retrieval of memories that would have otherwise been suppressed.

Dr Scott Cairney from the University of York said: “Memories of unpleasant experiences often intrude into our conscious mind in response to reminders, but tend to be fleeting and can be put out of the mind again, but we have previously shown that the brain's ability to suppress such intrusive memories is contingent on obtaining restful sleep.

“Suppression is a very clever function of the brain as it weakens all of the connecting traces of the memory, thereby inhibiting us from joining up all the dots to retrieve the full picture of the experience when it is triggered by an external stimulus.”

To understand how the brain does this, the team used functional magnetic resonance imaging (fMRI) scans to investigate the brain activity of 85 healthy adults, half of which had experienced a healthy night sleep in the sleep lab, and the other half stayed awake all night. 

They were asked to look at faces, which they had previously seen paired with images of scenes, some of which were emotionally negative, such as a picture of a car crash or a fight.  For each face they were asked to either recall the scene associated with it, or suppress the memory of the scene. 

When attempting to suppress the scene images, the well-rested participants showed more activation in the right dorsolateral prefrontal cortex - a brain region that controls thoughts, actions, and emotions - compared to those who stayed awake all night. 

The rested participants also showed reduced activity in the hippocampus - a brain region involved in memory retrieval - during attempts to suppress unwanted memories, demonstrating that they could ‘shut down’ the retrieval operations that underpin emerging intrusive thoughts.

They also found that individuals who obtained more rapid eye movement (REM) sleep, were better able to engage the right dorsolateral prefrontal cortex during memory suppression, pointing to a role for REM sleep in restoring the mechanisms in the brain that can help prevent unwanted memories from entering conscious thought. 

Dr Cairney explains: “The participants who were sleep deprived were unable to engage the area of the brain that helps us suppress unwanted memories. Consequently, they could not quash memory related processes in the hippocampus that give rise to intrusive thoughts. 

“This is really important to our understanding of mental health issues as it is well documented that those who suffer with anxiety, depression or PTSD, also have difficulty with sleep. Now that we have better understanding of the the mechanisms in the brain that can help restrict negative memories and thoughts, we can perhaps work on more targeted treatments and behavioural therapies that help with improving sleep and as a result support the brain in doing what it has so cleverly adapted to doing, allowing us to lead mentally fit lives.”

‘Memory control deficits in the sleep-deprived human brain’ is published in the journal Proceedings of the National Academy of Sciences. 

 

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Journal

Proceedings of the National Academy of Sciences

 

Synthetic chemicals and chemical products require a new regulatory and legal approach to safeguard children’s health

Few legal or policy constraints apply to the global chemical inventories of an estimated 350,000 products, according to the Consortium for Children’s Environmental Health

Boston College

Chestnut Hill, Mass (01/08/2025) – Nations must start testing and regulating chemicals and chemical products as closely as the current systems that safeguard prescription drugs or risk rising rates of chronic illnesses among children, according to a New England Journal of Medicine report by a group of experts writing as the Consortium for Children’s Environmental Health.

Global chemical inventories contain an estimated 350,000 products – such as manufactured chemicals, chemical mixtures, and plastics. Despite the risks of environmental pollution and human exposure, the manufacture of synthetic chemicals and plastics is subject to insufficient legal or policy constraints.

That regulatory vacuum must be replaced by new laws that prioritize health protection over the rampant production of chemicals and plastics, according to the co-authors, who include Boston College epidemiologist Philip Landrigan, MD, environmental law scholar David Wirth, biologist Thomas Chiles, and epidemiologist Kurt Straif.

“Under new laws, chemicals should not be presumed harmless until they are proven to damage health,” the authors said. “Instead, chemicals and chemical-based products should be allowed to enter markets and remain on markets only if their manufacturers can establish through rigorous, independent, premarket testing that they are not toxic at anticipated levels of exposure.”

In addition, the authors say chemical manufacturers and brands that market chemical products should be required to monitor their products after they have been released to the market in the same way that prescription drugs are monitored in order to evaluate any long-term negative health effects.

The call to action is the result of a two-year project by the group of the world’s most trusted independent scientists from 17 high-profile scientific institutions in the U.S. and Europe. The report was developed to enable a coordinated approach to reduce the ever-increasing levels of chronic disease being faced by children around the world.

Non-communicable diseases (NCDs) are the principal causes of morbidity and mortality in children today, the authors note. Their incidence and prevalence are on the rise. Emerging research links multiple NCDs in children to manufactured synthetic chemicals.

In the past half century, NCDs in children have risen sharply:

●  Incidence of childhood cancer has increased by 35 percent

●  Male reproductive birth defects have doubled in frequency

●  Neurodevelopmental disorders now affect one child in 6, and autism spectrum disorder is diagnosed in one child of 36

●  Pediatric asthma has tripled in prevalence

●  Prevalence of pediatric obesity has nearly quadrupled and driven a sharp increase in type 2 diabetes among children and adolescents

●  Certain chemicals have led to a reduction in IQ and thus massive economic damage

Most synthetic chemicals and related products are produced from fossil fuels – gas, oil, and coal. Production has expanded 50-fold since 1950, and is projected to triple again by 2050. Environmental pollution and human exposure are widespread.

Yet manufacture of synthetic chemicals and plastics is subject to few legal or policy constraints. Unlike pharmaceuticals, synthetic chemicals are brought to market with little prior assessment of their health impacts and almost no postmarketing surveillance for longer-term adverse health effects.

Fewer than 20 percent of these chemicals have been tested for toxicity, and fewer still for toxic effects in infants and children. Associations between widely used chemicals and disease in children continue to be discovered with distressing frequency, and it is likely that there are additional, still unknown links.

Protecting children from chemicals’ dangers will require fundamental revamping of current law and restructuring of the chemical industry, the co-authors write.

Safeguarding children’s health against manufactured synthetic chemicals will require a fundamental shift in chemical law that takes a more precautionary approach and prioritizes health protection over the unconstrained production of synthetic chemicals and plastics, specifically:

●  New laws that require chemicals to be tested for safety and toxicity before they are allowed to enter markets

●  Mandated chemical footprinting, which operates much like its better-known cousin carbon footprinting

●  Safer chemicals, reducing reliance on fossil carbon feedstocks, developing a diverse set of safer, more sustainable molecules and manufacturing processes

●  Policy reform, create a new legal paradigm for chemical management at a national level and a new global chemicals treaty

“Pollution by synthetic chemicals and plastics is one of the great planetary challenges of our time,” said lead author Landrigan, the director of Boston College’s Observatory on Planetary Health. “It is worsening rapidly. Continued unchecked increases in the production of chemicals based on fossil carbon endangers the world’s children and threatens humanity’s capacity for reproduction.”

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Journal

New England Journal of Medicine

DOI

10.1056/NEJMms2409092 

Method of Research

Data/statistical analysis

Article Title

Manufactured Chemicals and Children’s Health: The Need for New Law