Why Dreaming Leaves the Brain Running Low on Energy

By Tohoku U., August 1, 2026

https://scitechdaily.com/why-dreaming-leaves-the-brain-running-low-on-energy/

A mouse study reveals that the dreaming brain may consume energy faster than it can replace it. This hidden metabolic imbalance could offer new clues about how REM sleep supports complex internal processing. 

Credit: Shutterstock

The dreaming brain surges with energy, yet its neurons may consume it faster than they can replenish it.

A new mouse study from Tohoku University has uncovered a surprising energy imbalance during rapid eye movement (REM) sleep. As the brain entered this dream-rich stage, blood volume increased across the cortex, and astrocytes accumulated more metabolic fuel, yet ATP, the molecule neurons use as an immediate source of energy, declined.

The discovery challenges the simple assumption that delivering more fuel to the brain should immediately increase its usable energy. Instead, REM sleep may place such intense or unusual demands on neural circuits that energy consumption briefly outpaces production, even as the brain prepares additional resources.

The findings were published in Communications Biology.

“Ever felt exhausted after a vivid dream?” asks Professor Ko Matsui of Tohoku University. “Sleep may appear peaceful, but the brain is highly active, especially when dreaming. We were intrigued by this paradox and wanted to look into the scientific basis behind why dreaming is somehow tiring.”

The brain energy paradox during REM sleep. During REM sleep, astrocytic pyruvate levels increased along with the increase in local brain blood volume (left). In contrast, when neuronal ATP was measured with a fluorescent sensor, neuronal ATP decreased despite the increase in local brain blood volume (right). These findings suggest that, during REM sleep, increased energy supply does not simply lead to increased neuronal ATP. Instead, energy flow appears to be dynamically reorganized among blood vessels, astrocytes, and neurons. 

Credit: Yusuke Takahashi, Yoko Ikoma, Ko Matsui

Why Dreaming Demands So Much

REM sleep is sometimes called “paradoxical sleep.” Brain activity can resemble wakefulness, the eyes move rapidly beneath closed lids, and vivid dreams are common, yet most skeletal muscles become deeply relaxed. REM sleep has also been linked to memory processing, emotional regulation, and communication between distant brain regions, although its precise functions remain under debate.

To watch metabolism shift during natural sleep, the researchers coated the skulls of mice with a transparent UV-curable resin. This allowed them to observe much of the cortex without removing part of the skull, a procedure that can disturb blood vessels and supporting brain cells.

Using wide-field fluorescence imaging, the team tracked three parts of the brain’s energy system. Blood volume provided an indication of incoming fuel, pyruvate in astrocytes reflected the processing of glucose, and ATP revealed how much immediately usable energy was available inside neurons.

Astrocytes are positioned between blood vessels and neurons, making them important metabolic intermediaries. They absorb glucose from the bloodstream and convert it into substances that can be used to produce ATP. Their location also allows them to help match blood flow and energy delivery to the changing demands of neural activity.

Blood Flow Prepares for REM

During non-REM sleep, the researchers detected a close relationship between brain activity and circulation. Small fluctuations in theta frequency activity predicted changes in cortical blood volume about four to five seconds later. The result suggests that even during deeper sleep, blood vessels continue adjusting their behavior to match changing neural and metabolic needs.

Brain blood volume dynamics reorganize during the transition to REM sleep. During NREM sleep, fast local brain blood volume fluctuations propagated from anterior to posterior cortex in about 1 second (left). During the transition to REM sleep, local brain blood volume began to rise about 50 seconds before the ECoG-defined REM onset (center). This increase started in posterior cortex and spread anteriorly over about 15 seconds (right), suggesting that REM sleep is preceded by a posterior-to-anterior metabolic preparation process involving vascular responses. 

Credit: Yusuke Takahashi, Yoko Ikoma, Ko Matsui

The approach to REM sleep was dramatically different. Blood volume began rising roughly 50 seconds before REM sleep officially started. The increase appeared first in the rear of the cortex and then moved forward, indicating that the brain may begin preparing for the energy demands of REM well before conventional measurements identify the transition.

Once REM sleep began, pyruvate increased inside astrocytes. That pattern suggested that more metabolic material was becoming available or that astrocytes were breaking down more glucose. Yet ATP inside neurons moved in the opposite direction and fell.

Why Neuronal Energy Falls

The researchers do not yet know why. Neurons may burn through ATP as circuits reorganize, memories are processed, and communication increases between regions such as the hippocampus and cortex. Another possibility is that the transfer of metabolic fuel from astrocytes to neurons changes during REM sleep. The neurons’ mitochondria, which produce most cellular ATP, may also temporarily shift how they operate.

The decline does not necessarily mean that neurons are being deprived of energy. ATP levels reflect the balance between production and consumption. A falling concentration could therefore signal that neurons are using ATP faster than they can replace it during this unusually active sleep state.

Brain waves predict local brain blood volume fluctuations during NREM sleep. Through-skull fluorescence imaging visualizes cerebral blood vessels as dark “shadows,” allowing local brain blood volume dynamics to be estimated (left). During NREM sleep, theta-band brain activity closely matched local brain blood volume changes occurring about 4 seconds later (center). Vascular responses appear to be dynamically adjusted to neuronal activity, supporting on-demand energy supply (right). 

Credit: Yusuke Takahashi, Yoko Ikoma, Ko Matsui

The results also show why blood flow alone cannot reveal how much usable energy neurons possess. More blood reached the brain, and astrocytes accumulated more pyruvate, but neither change translated into higher neuronal ATP. Energy delivery, processing, transfer, production, and consumption appear to be regulated separately rather than moving together.

This flexible system may help explain how the brain performs extraordinary amounts of computation while consuming relatively little power. The adult human brain is estimated to operate on roughly 20 watts, comparable to a dim light bulb, despite continuously controlling perception, memory, movement, emotion, and internal body functions.

How REM Sleep Supports Brain Efficiency

Rather than distributing energy evenly, the brain may redirect resources according to its current needs. During REM sleep, it could prioritize selected networks involved in internal processing while temporarily changing how fuel moves among blood vessels, astrocytes, and neurons.

“Understanding how the brain balances energy supply and consumption may help explain what makes biological intelligence so efficient,” explains lead investigator Yusuke Takahashi. “REM sleep gives us a natural example of how the brain reorganizes its energy economy to support complex internal processing.”

By revealing a hidden metabolic shift during REM sleep, the findings offer a new way to investigate how sleep supports memory and how the brain remains remarkably efficient.

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A Massive Study Reveals the Brain Is Far More Flexible Than We Thought

By The Zuckerman Inst. at Columbia U.August 1, 2026

https://scitechdaily.com/a-massive-study-reveals-the-brain-is-far-more-flexible-than-we-thought/

Neurons become less specialized as information moves into higher-order regions of the cortex. This unexpected diversity may reveal how populations of brain cells encode complex situations without relying on rigid, easily labeled roles.

 Credit: Stock

A single neuron may help the brain recognize what it sees, track what the body is doing, and guide a decision, all at the same time.

Most neurons may be far more versatile than scientists once thought. In a major study published in Nature, researchers analyzed more than 14,000 individual neurons across 43 regions of the mouse cortex and found that most did not perform one clearly defined job. Instead, they responded to shifting combinations of sensory information, movement, and decision-making.

The findings attracted unusual attention even before publication, with preliminary versions downloaded more than 11,000 times. The attention underscores a fundamental question in neuroscience: Are neurons dedicated specialists, or can individual brain cells participate in many different processes?

The answer appears to depend on where a neuron is located. Strong specialists were found in primary sensory regions, including areas that process visual information. But as signals moved into brain regions involved in more complex processing, neurons became increasingly difficult to sort into distinct functional groups.

Why the Brain Defies Simple Labels

In most of the cortex, the researchers found a diverse population of neural generalists.

“We have to move away from this image of the brain as a machine made of gears, with every gear having an exact purpose that we can attach a label to,” said Stefano Fusi, PhD, a principal investigator at Columbia’s Zuckerman Institute, a member of the Kavli Institute for Brain Science and the paper’s co-senior author. “The brain doesn’t work like that. Instead, most neurons can display a huge diversity of responses, and this can help the brain solve a huge number of different tasks.”

The discovery challenges a familiar way of describing the brain. Scientists often speak of neurons that respond to faces, locations, movements, or other particular features. Such labels can be useful, but the new findings suggest they may capture only one part of what a cell does.

A neuron that appears devoted to one feature under certain conditions may also encode several other pieces of information. Its activity might reflect what an animal sees, which choice it is considering, how it moves, and whether it expects a reward.

That flexibility could help explain how the brain handles new situations without requiring a separate group of cells for every possible experience.

Resolving a Long-Running Neuroscience Debate

Whether neurons are specialists or generalists “is an old, important question, and one which researchers have really strong opinions on,” said Lorenzo Posani, PhD, the study’s co-lead author and a principal investigator at the Paris Brain Institute and France’s CNRS. Posani conducted the work while at Columbia’s Zuckerman Institute.

The debate has remained unresolved partly because neuroscience experiments are often difficult to compare. Different laboratories may study different animals, brain regions, behaviors, or recording methods. One experiment might reveal neurons that appear highly specialized, while another finds cells responding to several unrelated variables.

The new study reduced those inconsistencies by examining a massive standardized dataset from the International Brain Laboratory. The recordings followed mice performing the same decision-making task while researchers measured individual neurons across dozens of cortical regions.

This allowed the team to compare neural activity across much of the cortex under the same conditions rather than piecing together results from unrelated experiments.

Specialists Become the Exception

The pattern was clear. Neurons near the beginning of the brain’s processing hierarchy tended to have more defined roles. Visual neurons, for example, were more likely to respond consistently to particular sensory features.

Farther along the hierarchy, those clean divisions largely disappeared. Neurons became more varied, with each cell responding to a different mixture of information. The cortex appeared to favor diversity over a rigid system of narrowly defined cell types.

“We’re not saying that there are no specialized neurons,” said Fusi, who is also a professor of neuroscience at Columbia’s Vagelos College of Physicians and Surgeons and a member of Columbia’s Center for Theoretical Neuroscience. “We’re saying they are the exceptions. They’re not the rule.”

Organized Brain Regions, Diverse Neurons

Despite this diversity, the activity was not random.

The researchers could often determine which brain region a neuron came from simply by examining its responses during the task. Cells within the same region shared broad characteristics, even though individual neurons rarely behaved in precisely the same way.

“For example, compare this to maps of voter opinions,” Posani said. “There are clear clusters where people generally vote the same way. But when you zoom in, you see mixes of opinions.”

The same principle appeared across the cortex. Brain regions remained distinguishable at the population level, but their individual neurons showed a wide range of response patterns.

The researchers also found that individual neurons rarely responded in exactly the same way.

A Flexible, High-Dimensional Brain Code

“Each is versatile in its own way,” said study co-lead author Shuqi Wang, a doctoral student at École Polytechnique Fédérale de Lausanne in Switzerland.

This diversity may be one of the brain’s strengths. If thousands of neurons responded identically, much of their activity would be redundant. By encoding different combinations of information, a population can represent far more possibilities.

Consider an animal viewing objects that differ in color and shape. Some neurons might respond mainly to color, while others reflect shape, movement, choice, or a combination of those variables. Together, their activity could distinguish a red circle from a red square, a black circle, or many other possibilities.

Neuroscientists describe these complex population patterns as “high-dimensional” representations. Rather than storing each feature separately, groups of neurons encode many overlapping variables at once. This creates a flexible neural code that can separate similar situations and support different behaviors.

“You can reuse these high-dimensional representations for lots of different tasks,” Fusi said.

Why Single Neurons Can Be Misleading

An individual neuron may respond to several variables, making its activity look confusing or inconsistent when viewed alone. The underlying information becomes clearer only when researchers examine the coordinated patterns produced by large populations of cells.

That idea marks a shift from decades of research that often searched for neurons with simple, easily labeled responses while setting aside cells that did not fit an obvious category.

Fusi said the field historically focused “on one neuron at a time, discarding all neurons whose responses could not be understood.”

The apparently messy activity of those cells may not have been meaningless. It may have reflected a richer and more adaptable form of information processing than researchers could detect with older approaches.

New Clues to Brain Disorders

Understanding this population code could eventually help scientists investigate what changes when brain networks malfunction. Neurological and psychiatric disorders may not always involve the failure of a single specialized cell type. Some could instead arise when patterns across large groups of versatile neurons lose their organization, flexibility, or ability to separate information.

The researchers also want to determine whether neurons shift between specialist and generalist behavior depending on the task. A cell that responds broadly in one situation might take on a narrower role when the brain faces a different demand.

“There is still a lot to discover,” Fusi said.

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Study Finds a Surprising Link Between Gut Microbes and Aging

By U. of Hawaii at Manoa, August 1, 2026

https://scitechdaily.com/study-finds-a-surprising-link-between-gut-microbes-and-aging/

Certain gut bacteria may act as subtle markers of biological aging, offering new clues about longevity and resilience. 

Credit: Shutterstock

Certain gut bacteria were linked to slower or faster biological aging.

The communities of bacteria living in the gut may carry clues about how rapidly the body is aging. Researchers at the University of Hawaiʻi at Mānoa found that certain microbial patterns were associated with faster or slower biological aging, adding to evidence that gut health is connected to longevity.

Published in Scientific Reports, the study found that variation in gut bacteria accounted for about 15% of the differences in participants’ biological aging rates. The results indicate that the gut microbiome contains measurable information about aging processes occurring at the molecular level.

“This study advances our understanding of the relationship between the gut microbiome and biological aging,” said senior author Alika K. Maunakea of the UH Mānoa John A. Burns School of Medicine. “We found that microbial patterns in the gut were significantly associated with molecular measures of aging, even independent of chronological age. These findings open important new directions for understanding how modifiable biological systems influence long-term health trajectories and longevity.”

Blood and stool reveal aging patterns
Researchers examined stool and blood samples from 123 adults spanning a wide range of ages. They compared the bacteria present in each participant’s gut with blood-based biomarkers designed to estimate the body’s rate of aging. Chronological age simply counts the years a person has lived, while biological aging measures are intended to reflect how quickly the body is changing physiologically.

Alika K. Maunakea, professor at the UH Mānoa John A. Burns School of Medicine, is a senior author of a study that found that certain gut bacteria are associated with the pace of biological aging. The research adds to growing evidence that the gut microbiome may play an important role in long-term health and healthy aging. 

Credit: University of Hawaii

Gut microbial composition was specifically associated with DunedinPACE, a next-generation biomarker that measures the pace of biological aging. Several bacterial species showed especially strong relationships with aging patterns. Bifidobacterium adolescentis was among the clearest microbial signatures associated with slower aging, while Succinivibrio dextrinosolvens had one of the strongest associations with faster aging.
Gut microbes may reflect resilience

Lead author Braden P. Kunihiro said the results demonstrate why the gut microbiome is attracting greater attention in precision health research.

“The gut microbiome is highly responsive to lifestyle, diet, environment and other everyday exposures,” Kunihiro said. “Our findings suggest that the microbiome may reflect important aspects of biological resilience and aging in ways that could eventually help inform future wellness and healthy aging strategies.”

This research adds to growing evidence that the gut microbiome may play an important role in long-term health and healthy aging. 

Credit: University of Hawaii

Native Hawaiian and Pacific Islander participants were also included in the research, helping represent populations that have historically been overlooked in studies of aging and the microbiome. Co-author Ruben Juarez said the findings could help clarify how social conditions and environmental exposures leave lasting biological effects.

“The microbiome exists at the intersection of behavior, environment and human biology,” Juarez said. “Studies like this help illuminate potential pathways through which lived experiences and social factors influence long-term health outcomes.”

The association does not prove cause

The researchers cautioned that the observed relationship does not demonstrate that gut bacteria directly control the pace of aging. Additional studies will be needed to determine whether deliberately changing the microbiome can influence how quickly the body ages.

“This is an important early step toward understanding the gut microbiome’s relationship with healthy aging,” Maunakea said. “Future research will help clarify the mechanisms involved and whether these microbial signatures may eventually contribute to precision approaches for promoting long-term health and wellness.”

The Life of Earth

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Feeling Lonely May Take a Bigger Toll on Health Than Expected

By U. of Bristol, July 23, 2026

https://scitechdaily.com/feeling-lonely-may-take-a-bigger-toll-on-health-than-expected/

Loneliness and social isolation may affect health in different ways, with the strongest signals emerging for mental health and well-being.

 Credit: Stock

Loneliness appears closely tied to poorer mental health, well-being and overall health.

Feeling lonely is closely associated with poorer mental health, reduced well-being and worse overall health, according to collaborative research led by the University of Bristol, Nesta and Amsterdam UMC. Social isolation was also linked to lower well-being, while loneliness was associated with having multiple health conditions.

Loneliness is increasingly viewed as a public health concern as evidence connecting it with poor health continues to grow. A central question remains unresolved, however: does loneliness itself contribute to declining health, or do other underlying factors explain the relationship?

Three methods strengthen the evidence

Working with researchers from the universities of Oxford and Manchester, the group approached the question through three complementary methods: observational analysis, comparisons between siblings and Mendelian randomization, a genetics-based technique used to investigate possible causal relationships.

The researchers drew on the UK Biobank and large-scale genome-wide association studies to examine two related but distinct experiences. Loneliness reflects the perceived quality of a person’s relationships, while social isolation describes the number of social connections they have. The findings were published in Nature Communications.

Mental health shows the clearest link

Across the analyses, both loneliness and social isolation were connected with poorer mental health and lower well-being. Loneliness was also associated with worse general health.

The study did not provide clear evidence that either experience affected particular physical health conditions. However, the researchers caution that such effects cannot yet be excluded.

Taken together, the results support treating loneliness, and potentially social isolation, as public health concerns because of their relationships with mental health, well-being and general health.

Loneliness becomes a public health priority

As loneliness receives greater recognition as a public health challenge, efforts to address it could benefit individuals as well as society more broadly.

Dr. Zoe Reed, Research Fellow in the School of Psychology and Neuroscience at the University of Bristol, and corresponding author, said: “Our findings suggest that loneliness, and possibly social isolation, are still important public health concerns, especially for mental health and general health. Supporting people who feel lonely or socially isolated could help improve mental health, well-being and overall health.”

Lauren Bowes Byatt, Director of Nesta’s healthy life mission, added: “This research underlines that loneliness is likely to have a detrimental impact on our mental health and well-being. While this link may seem obvious, the topic has long been understudied. Studies like this can help to bridge this research gap, and by understanding how loneliness or social isolation may be contributing to ill-health, we can get closer to new and more effective solutions.”

Long-term effects remain uncertain

Further research is needed to clarify how loneliness and social isolation influence health and to identify the most effective ways of reducing their effects.

Because the study examined middle-aged and older adults, future work will need to determine whether the same patterns appear among younger people. Researchers must also investigate persistent or long-term loneliness, since participants’ loneliness was measured at only one point in time.

The findings add to evidence that loneliness and social isolation extend beyond the social sphere. Their links with well-being and mental and physical health make them important considerations for public health policy and practice.

The birth of modern Man

https://chuckincardinal.blogspot.com/

There's One Creature of The Deep That Can Scare Even Orcas Away

31 July 2026, By M. Starr

https://www.sciencealert.com/theres-one-creature-of-the-deep-that-can-scare-even-orcas-away

(kertu_ee/iStock/Getty Images Plus)

In recent years, our perception of the ocean's pecking order has been turned on its head.

Ever since Jaws, great white sharks have loomed large in the popular imagination as the undisputed rulers of the sea.

Then scientists discovered that these fearsome predators had a nemesis of their own: the mighty orca (Orcinus orca), sleek and cunning, hunting white sharks for their tender, nutrient-rich livers.

You might think there's very little that could rattle an orca.

You'd be wrong.

Just the hint of a squeal from a pod of long-finned pilot whales (Globicephala melas) can send orcas packing.


And the best part is that nobody really knows why.

https://www.youtube.com/watch?v=Q1_0IRv7prg

"Killer whales, the oceans' apex predators, respond to acoustic signals of pilot whales and likely perceive their presence as a threat," wrote a team led by marine biologist Anna Selbmann of the Sudurnes Science and Learning Center in Iceland in a paper published in Scientific Reports in January 2026.

"However, it remains unclear why this apex predator avoids a smaller, seemingly inferior aggressor."

The story begins in 2012, when a group led by marine biologist Charlotte Curé published a curious observation. Playing orca vocalizations to long-finned pilot whales in the wild acted as a sort of siren call that the pilot whales couldn't resist.

If they were within hearing range, they moved towards the sound.

Then, another group led by marine scientist Renaud de Stephanis of the Spanish National Research Council documented something even curiouser.

In a paper published in 2014, they noted that in every documented encounter between pilot whales and orcas in the wild from 2004, the orcas skedaddled. Once the pilot whales show up in orca-infested waters, the orcas no longer want to be there.

The long-finned pilot whale is a species of dolphin. (Vsevolod Rudyi/iNaturalist, CC BY 4.0)



The reason this is so curious is that there didn't appear to be a good ecological reason for it.

After conducting a field investigation in the Strait of Gibraltar, de Stephanis and his team found that two cetacean species don't compete for the same food, nor do they prey upon each other.

In addition, the long-finned pilot whale is significantly smaller than the orca. It should not pose a significant threat.

They concluded that maybe, at some point in the past, orcas may have preyed upon the pilot whales, and the pilot whales have a long memory, but there's not much evidence for that interpretation either.

Selbmann and her colleagues were perplexed – but fascinated.

They wanted to study more interactions between the two species.

In a 2022 paper, they analyzed data from research platforms and whale-watching tours in six regions of Iceland from 2007 to 2020, documenting when each species was in the area. Pilot whales were only seen during the summer months – but they often showed up in the orcas' favorite hangout spots.

Here's where it got weird.

In most of the 24 encounters – 68 percent – the orcas simply avoided meeting the pilot whales by moving away before the latter muscled in.

Long-finned pilot whales (left) and orcas (right) porpoising during a high-speed chase in Vestmannaeyjar, Iceland in July 2019.

 (Katarína Klementisová, Curt Hanson/Selbmann et al., acta ethol., 2022)

But in 28 percent of the encounters, a high-speed chase ensued, with both species porpoising along at a rate of up to 13.5 knots (25 km/h) – a type of motion that involves repeatedly leaping from the water to increase speed.

By 2026, the observations now span more than two decades, and they all point in the same direction: Orcas really do avoid long-finned pilot whales.

But one question lingered. Were the orcas really reacting to the pilot whales, or to something else happening during these encounters?

Previous studies had played recorded orca sounds to pilot whales.

Selbmann and her colleagues took the pilot whales out of the equation. Instead of waiting for the species to meet in the wild, they played recordings of pilot whale calls to tagged orcas.

The response was striking. The orcas tightened up their group formations, changed their vocal behavior, turned away, and sped up. The pilot whale calls alone were sufficient to invoke an aversive reaction in orcas.

"As previous work demonstrated that pilot whales are attracted to killer whale sounds, our study further demonstrates that acoustic signaling can mediate these interspecific interactions in both directions," the researchers wrote.

We still don't really know why the pilot whales gun so hard for orcas, or why the orcas flee; as the researchers point out, no direct physical attacks by pilot whales on orcas have been reported, despite the many observed interactions.

One possibility is a behavior known as mobbing. Rather than fleeing a dangerous predator, some animals band together to harass it until it leaves the area.

It's most frequently observed in birds – think of how crows might harass a student wearing a mask, or mynahs yelling about a cat, for example. It's less effort to get up and leave than to deal with a dive-bombing flock of birds, so that's what the predator does.

It's only a theory, though. Other explanations, such as competition for resources or protection of vulnerable calves, cannot be ruled out.

Still, there might be a life lesson in this for all of us. If you can't be the biggest and the strongest, you might be able to achieve your dreams by being the most annoying.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Reveal The Chain Reaction That Leads to Gluten Attacking The Gut

01 August 2026, By D. Nield

https://www.sciencealert.com/scientists-reveal-how-gluten-reactions-in-the-gut-lining-lead-to-celiac-damage

(Chatchai Tuppavasu/Getty Images/Canva)

Celiac disease is a serious lifelong condition, where the immune system attacks the small intestine whenever the gluten protein is digested. For people with the condition, wheat, barley, and rye are all off the menu.

We know that genetics play a part in triggering celiac disease, and that certain gene variations make people more vulnerable to developing it. What's less clear is exactly how the loud alarm that sounds in the immune system leads to tissue damage.

In a comprehensive review published in Frontiers in Immunology, researchers from the University of Rome Tor Vergata pulled together findings from more than 100 previous studies to get a wider picture of the celiac disease chain reaction – getting us closer to figuring out how it works, and how it might be better treated.

A multitude of factors contribute to a healthy gut bacteria balance.

 (Marafini et al., Front. Immunol., 2026)

"We here review the available evidence supporting the role of immune cells in celiac disease-associated tissue damage and discuss the basic mechanisms by which this destructive immune response is amplified," write the researchers in their published paper.

That emphasis on amplification is key to the review. Only some people with a genetic predisposition to celiac disease go on to develop it, so there must be other contributing factors (amplifiers) at play.

What's well established is that one factor in developing celiac disease comes from a disruption to the delicate balance of bacteria in the gut. The immune system needs to keep out dangerous threats, without going on the offensive to the extent that healthy tissue gets affected.

A multitude of disruptive problems occur in celiac disease.

 (Marafini et al., Front. Immunol., 2026)

When it comes to gluten, an enzyme called tissue transglutaminase 2 (TG2) helps to break it down – but in those with certain gene variants, this makes gluten's by-products look like foreign invaders to the immune system, which dispatches an army of soldier T-cells to attack.

"Under normal conditions, TG2 is mostly inactive in the intestine," write the researchers in their published paper.

"Nevertheless, inflammatory stimuli or cellular stress can increase the production and enzymatic activity of TG2, thus escalating immune responses to gluten."

However, T cells and the inflammatory signals they produce aren't the whole story.

 Those signals and other accompanying chemical messages kick immune cells called intraepithelial lymphocytes into action, which actually kill off the cells in the gut lining.

There's then more amplification: The review points to more recent research suggesting that structural cells in the gut called stromal cells communicate with the immune system to perpetuate the damage.

Other reviewed studies provide evidence that the gut bacteria mix has an influence on the whole process, as do other wheat proteins and antiviral-type signals called type I interferons, all contributing to the stress that the gut lining is put under.

And with so many variables contributing to gut bacteria, it follows that these variables may be related to celiac disease too.

"Some microbial communities may affect not only gluten deamidation but also activation of TG2, hence suggesting that celiac disease pathogenesis requires the interplay of genetic, environmental, and immunological factors," write the researchers.

This review adds to the findings of a 2024 study published in Gastroenterology, which found that the gut lining can be an active participant in celiac disease, not just a victim under attack from T cells.

That's backed up by the other research linked to from this review, providing the most comprehensive look yet at how the starting gun for the condition has a series of knock-on effects that all contribute to the related symptoms.

Without careful monitoring of their diet, those with celiac disease – around 1 in a 100 people – can experience bloating, pain, diarrhea, constipation, or vomiting simply by eating the wrong foodstuff.

Thankfully, better understanding the mechanisms behind the condition could eventuall led to new treatments beyond going gluten-free.

"It will be necessary to further improve celiac disease-like models to unravel the order of pathogenic events and to carry out preclinical testing of novel therapeutic strategies," write the researchers.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Tested an 8-Hour Eating Window and Found a Surprising Brain Benefit

By American Society for Nutrition, July 29, 2026

https://scitechdaily.com/scientists-tested-an-8-hour-eating-window-and-found-a-surprising-brain-benefit/

An eight-hour eating window may offer the aging brain a modest boost beyond weight loss alone. 

Shutterstock

Limiting the daily eating window may provide brain benefits beyond those associated with weight loss.

Eating within a shorter daily window may provide cognitive benefits beyond those associated with weight loss alone, according to results from a small clinical trial. The pilot study followed older women with overweight or obesity during a weight-loss program and found modest improvements on certain thinking tests among participants who compressed their daily eating period rather than only cutting calories.

“Losing weight alone will ward off some of the aging-related cognitive decline, and these data suggest that there may be additional benefits if you stop eating 4 hours prior to going to sleep and reduce food intake to 8-9 hours per day, compared to the usual eating window of 12 hours per day,” said Sue Shapses, PhD, RD, DFASN, professor at Rutgers University and Rutgers-RWJ Medical Center, the study’s Principal Investigator.

Shapses and her colleagues presented the results at NUTRITION 2026, the American Society for Nutrition’s flagship annual meeting.

Lifestyle changes could alter dementia risk

As populations grow older, Alzheimer’s disease and other forms of dementia are becoming increasingly common. Women and people with overweight or obesity generally face a greater likelihood of developing these conditions. Although diet and other lifestyle habits have been associated with dementia risk, relatively little research has tested whether changing those factors can lower it.

Two eating schedules put to the test

The trial included 47 women between ages 50 and 79 who had overweight or obesity. Every participant received guidance to reduce daily calorie intake by 500 calories. Of the group, 26 women were instructed to consume all food within fewer than nine hours each day, while the remaining participants continued eating across a typical window of about 12 hours. Those assigned to time-restricted eating generally ate between 10 a.m. and 6 p.m. Their average eating period was 8.2 hours per day, compared with 12.3 hours among women following the standard schedule.

A shorter window improves select skills

After six months, women in both groups had lost an average of approximately 15 pounds. Despite similar weight loss, participants eating within an 8-9 hour period showed significantly greater improvements in spatial planning and problem-solving than those maintaining a 12-hour window. They also tended to make fewer mistakes on tests of memory and learning, although that difference was not statistically significant. No meaningful differences appeared in multitasking ability or reaction time.

“There was a modest effect of time-restricted eating to improve spatial planning and problem-solving and on reducing errors related to memory and learning,” said Shapses. “These outcomes suggest a better ability to remember information during everyday tasks and reducing mistakes related to memory, attention and problem-solving. Reductions in the eating window predicted greater improvements.”

Larger trials must confirm the findings

Because the pilot study involved a small number of participants, the researchers emphasized that larger trials are necessary to verify the results. They also intend to examine possible biological explanations for the apparent benefits, including links among circadian rhythms, nutrient-sensing pathways, inflammation and metabolic health.

The Life of Earth

https://chuckincardinal.blogspot.com/

'Clear Evidence': Ancient DNA From Chilean Mummies Reveals Who Brought Smallpox to The Americas

31 July 2026, By D. NIELD

https://www.sciencealert.com/clear-evidence-ancient-dna-from-chilean-mummies-reveals-who-brought-smallpox-to-the-americas

(Anatoli Myshlyaev/Moment/Getty Images)

Smallpox is an age-old scourge with a terrible history.

Caused by the variola virus, it's thought to have been responsible for some 4 million total deaths in Indigenous communities in the Americas after European colonizers arrived – communities with no immune protection against the virus.

Previously, the evidence for this has been a historical paper trail.

Now though, 500 years later, we have the first solid genetic evidence that it was indeed smallpox contracted from Europeans that led to this catastrophic population decline in Indigenous communities.

Researchers from institutions in Ireland and Chile have discovered variola virus DNA on two naturally mummified corpses recovered in northern Chile, the remains of people believed to have died between 1492 and 1631 CE.

https://www.youtube.com/watch?v=yqUFy-t4MlQ

As explored in a new study published in Science, the virus genomes are almost identical – suggesting both individuals were infected at the same time – and place the disease in South America very soon after Europeans arrived.

It's a long-awaited breakthrough for ancient genetic evidence that's often so difficult to find on human remains after significant time has passed.

"This is not unique to smallpox but to ancient pathogens, humans, and other species broadly," biological anthropologist Constanza de la Fuente Castro, from the University of Chile, told ScienceAlert.

"We are working with DNA that is in low concentration and has accumulated damage over time. This is affecting our ability to recover it, but it is also challenging to analyze."

The researchers tracked lineages of the virus over time and across continents.

 (Romero González et al., Science, 2026)

The virus lineage was named CAM9 by the researchers. While it died out well before smallpox was eventually eradicated, when the team built up a 'family tree' of the virus, this strain fitted neatly between medieval European strains and modern variants.

You can think of it a bit like finding the remains of actual people – people we know to have descended from Europeans, found in Chile, after colonizers began arriving. Only here it's virus DNA, not human.

"The CAM9 genomes serve as a snapshot of the viral evolution," genomicist Shigeki Nakagome, from Trinity College Dublin, told ScienceAlert, "helping us understand which evolutionary changes had already occurred before smallpox reached the Americas during the early colonial period, and which changes occurred later and eventually gave rise to the lineage ancestral to all 20th-century strains."

What also emerged from charting out the ancestry of CAM9 was that its evolution slowed dramatically in the Americas for a couple of centuries shortly after this.

The genetic mutation rate of the virus sped up again in the 19th century, which the researchers suggest was down to widespread vaccination drives.

"Recovering ancient viral DNA is extremely challenging, so seeing clear evidence that these individuals were infected with smallpox was a remarkable moment for the entire team," Nakagome said.

"While the mechanisms behind this pattern require further investigation, it suggests that major changes in human demography and epidemiology may have influenced the adaptive landscape of the virus."

The smallpox virus. 

(Callista Images/Getty Images)



Besides giving us a better understanding of the spread of smallpox and its adaptations over time, and how a virus can react to human events such as colonization and vaccination, the study again highlights the wealth of expertise and ancient archaeological treasures to be found in countries such as Chile, which are part of what is sometimes referred to as the Global South.

The researchers are calling for a better balance between resources and funding for science in the Global South and the Global North, so that findings like these can be analyzed and preserved in the countries where they're discovered.

"I have known people working for decades in ancient DNA in South America who have sometimes been completely pushed out by foreign researchers with little interest in regional questions," De La Fuente told ScienceAlert.

"If we prioritize capacity building over exporting samples, it may take us longer to publish, but that knowledge will be rooted in the region, rather than extracted from it. It is worth the wait."

The Life of Earth

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Earth May Be Twice As Vulnerable to Extreme Solar Storms As Scientists Thought

BY LANCASTER U., JULY 30, 2026

https://scitechdaily.com/earth-may-be-twice-as-vulnerable-to-extreme-solar-storms-as-scientists-thought/

Illustration of solar wind streaming from a fuming sun drives auroras bright enough to be seen far from the poles, a dazzling signature of an extreme geomagnetic storm. 

Credit: Nithin Sivadas, NASA Goddard Space Flight Center

Earth may be far more vulnerable to powerful solar storms than scientists realized, with extreme events potentially hitting modern technology twice as hard as previous models predicted.

Earth’s magnetic shield may not have the safety limit scientists once thought it did. New research suggests that the most powerful solar storms could disturb the planet’s upper atmosphere up to twice as severely as traditional estimates predict.

The finding challenges a decades-old assumption about how Earth responds when it is struck by unusually intense solar wind. Rather than reaching a maximum and leveling off, the planet’s geomagnetic response may continue growing as conditions become more extreme.

That could have serious consequences for a world increasingly dependent on satellites, GPS, radio communications, aviation, and interconnected power grids.

The study, published in Nature, was led by Dr. Nithin Sivadas of NASA’s Goddard Space Flight Center and included Dr. Maria Walach of Lancaster University. It examined why measurements have long appeared to show a ceiling on the strength of geomagnetic activity.

How Space Weather Threatens Technology

Space weather begins with activity on the Sun. The solar wind, a continuous flow of electrically charged particles, moves outward through the solar system and interacts with Earth’s magnetic field. Solar eruptions can greatly intensify this flow, sending disturbances toward the planet.

When those particles reach Earth, they can transfer energy into the magnetosphere and generate powerful electric currents in the upper atmosphere. The same process can produce brilliant auroras, but during extreme events it can also interfere with satellites, disrupt navigation and communication signals, increase radiation exposure for astronauts and pilots, and induce damaging currents in power networks.

Dr. Walach said, “Our planet’s magnetic field does a really great job of protecting us against many space weather effects, and so they often just show up as glitches or beautiful auroras. There are, however, extreme cases where satellites unexpectedly fall back to Earth, or we lose communication and GPS signals.”

The Magnetic Shield’s Supposed Limit

Scientists previously believed that Earth had a built-in limit on how strongly it could respond. Measurements indicated that atmospheric currents rose as the solar wind intensified, but eventually stopped increasing at the same rate. Researchers developed several physical explanations for this apparent saturation, including theories in which the magnetosphere restricted the amount of energy entering the upper atmosphere.

The new study proposes a very different explanation. The supposed ceiling may be a statistical illusion created by uncertainty in the measurements themselves.

Solar wind conditions are usually recorded by spacecraft near the first Lagrange point, or L1, roughly 1 million miles (1.6 million kilometers) closer to the Sun than Earth. From there, the spacecraft can provide advance warning of incoming space weather. However, the solar wind continues to move and change before it reaches the planet.

That distance creates uncertainty about both the timing and strength of the solar wind that actually strikes Earth. A particularly extreme measurement at L1 may not perfectly represent conditions at the magnetosphere several minutes later.

Regression to the Mean

This becomes especially important when researchers analyze rare events. Exceptionally high measurements are more likely to include unusually large errors. The true conditions associated with them will often be closer to the average, a statistical tendency known as regression to the mean.

As a result, an extreme solar wind measurement at L1 may be compared with a less extreme response at Earth. When many such observations are combined, the mismatch can make it appear that Earth has stopped responding proportionally, even when no physical limit has been reached.

The researchers tested that possibility using more than 1 million measurements collected by NASA spacecraft orbiting much closer to Earth. They also used statistical methods to account for uncertainty in the timing and intensity of the solar wind.

Once those uncertainties were corrected, the apparent saturation largely disappeared. Earth’s geomagnetic response remained closely proportional to the strength of the solar wind across the observed range. The analysis indicates that the effects of the most extreme storms could be about twice as large as earlier models suggested.

Preparing for Rare Extreme Storms

The findings do not show that Earth’s response will keep increasing under every possible condition. The strongest solar storms are extremely rare, so scientists have little direct evidence of how the planet would react to an event that may occur only once every few hundred or thousand years.

However, the study finds no convincing statistical evidence for the protective ceiling that has been incorporated into many theories and models. That means models that assume Earth’s response eventually levels off may underestimate the risks from the most powerful solar storms.

Dr. Walach said, “If there is no upper limit to our planet’s response to the solar wind, modeling for extreme cases needs to take this into account, and we should be vigilant of space weather effects. Fortunately, these very extreme cases are rare, but this also means we have limited data to work with, and only time will tell what happens at the very extreme one-in-a-thousand-year kind of event.”

Dr. Sivadas said, “We usually assume the truth may be around its measurement. But probability theory says it leans one way. That’s why space weather risks appear underestimated.”

The Life of Earth

https://chuckincardinal.blogspot.com/

Ancient hunter-gatherers mastered open-water voyages thousands of years before farming

ByA. Ionescu, Earth.com staff writer

https://www.earth.com/news/ancient-hunter-gatherers-mastered-open-water-voyages-thousands-of-years-before-farming/

07-30-2026

Thousands of years before farming reached the Mediterranean, small bands of hunter-gatherers were apparently sailing across open water on a regular basis.

Their journeys stretched at least 62 miles (100 kilometers), likely between Sicily and Malta, helping sustain that connection for more than a millennium. The discovery overturns long-standing assumptions about just how capable Europe’s last hunter-gatherer societies were at sea.

The research was led by Jimbob Blinkhorn from the University of Liverpool, along with Professor Eleanor Scerri from the Max Planck Institute of Geoanthropology.

The team examined new evidence from Malta, one of the most remote islands that hunter-gatherers colonized anywhere in the Mediterranean.

A puzzle hidden on Malta

The core problem the researchers set out to solve was simple to state but difficult to explain. Malta is far too small to have supported a hunter-gatherer population large enough to survive in total isolation for hundreds of years.

Yet archaeological evidence shows people living there continuously for roughly a millennium.

The researchers argue that this combination only makes sense if the island’s occupants maintained ongoing contact with a broader social network through repeated long-distance sea voyages.

“The ability to engage in long-distance seafaring marks a major transition in human history, in which previously impassable maritime barriers became the frontiers of new connections,” Scerri said.

“In the Mediterranean, single-stage, long-distance open-water sea voyaging is first documented in the Mesolithic.

“On Malta, we documented a continuous Mesolithic presence from at least 8,400 to 7,400 years ago. Was this an accidental stranding, or is it representative of a previously unknown seagoing network?”
How many people could survive?

To answer that question, the researchers combined modern ethnographic data with paleoclimate records and sea-level models to estimate how large a hunter-gatherer population Malta could plausibly have supported.

“Unlike farmers, hunter-gatherers are dependent on wild, natural food resources, whose abundance is largely governed by the climate for a given area,” Blinkhorn said.

“By modeling the relationship between modern hunter-gatherer population sizes and their environment, we were able to predict potential past population sizes using high-resolution paleoclimate datasets.

“While Malta was once connected to Sicily by a land bridge, this was inundated around 14,000 years ago, cutting Malta off and limiting the land area available to support hunter-gatherer populations.”

Preventing inbreeding and collapse

The team’s modeling put Malta’s maximum possible post-isolation population between 144 and 170 individuals. More realistic estimates based on ethnographic comparisons suggested the population was considerably smaller.

That low-density prediction holds across the full thousand-year span during which archaeological evidence documents continuous hunter-gatherer occupation on the island.

That population size falls dramatically short of what would have been needed for a group to survive that long in isolation.

“Long-term survival of a population, such as over a millennium evident in the archaeological record, would require 500 to 1,000 reproductive-age adults,” Blinkhorn said.

The researchers predicted that Malta’s population was far smaller than the minimum needed to avoid inbreeding.

They concluded that the island’s hunter-gatherers must have maintained repeated overseas connections with a wider gene pool to prevent population collapse.

Without sustained contact with mainland populations, genetic collapse through inbreeding would have been essentially inevitable. Yet the archaeological record shows no such collapse across a thousand years of continuous occupation.

What hunter-gatherers were capable of

Taken together, the findings point to something far more sophisticated than isolated, one-off voyages of discovery.

“Our study proves that Malta was part of a hitherto unknown, sustained, long-distance sea voyaging network,” Scerri said.

“The last European hunter-gatherers were not only reconfiguring the use of land and sea in a way that preempts the modern world, they were also maintaining social networks in ways we don’t see before.”

That reframing carries real weight for how archaeologists understand this period of prehistory more broadly.

The traditional understanding of Mesolithic hunter-gatherer societies as small, isolated bands tied closely to a single stretch of coastline does not seem to hold.

The findings suggest at least some of these communities were maintaining organized maritime networks capable of supporting repeated, purposeful journeys across open water.

The birth of modern Man

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'Completely Transformed My Understanding': Scientists Uncover Hundreds of Hidden Structures Beneath The Amazon

30 July 2026, By M. Starr

https://www.sciencealert.com/completely-transformed-my-understanding-scientists-uncover-hundreds-of-hidden-structures-beneath-the-amazon

LIDAR image of the Aquiry geoglyph site at Piloto. 

(© Martti Pärssinen and Fabio de Novaes, supplied)

Today, the Amazon rainforest is revered as one of Earth's most immaculate wildernesses.

Nearly 2,000 years ago, it looked very different.

Between around 600 BCE and 850 CE, a civilization known as the Aquiry transformed swaths of southwestern Amazonia, carving enigmatic geometric earthworks into the landscape.

Now, a new LIDAR survey suggests that civilization was even larger than archaeologists imagined, hinting at a people that built as many as 30,000 earthworks and had a peak population of up to 3 million people around 200 CE.

For archaeo-anthropologist Martti Pärssinen of the University of Helsinki, the realization was transformative.

"I first experienced such a moment in 2002, when I flew with Alceu Ranzi and Sanna Saunaluoma over the monumental geometric earthworks and observed ancient roads connecting the sites in the state of Acre, Brazil, a region that had long been regarded as pristine rainforest," Pärssinen told ScienceAlert.

"It completely transformed my understanding and made me realize how mistaken earlier assumptions had been.

"More recently, I felt something similar when I came to understand that there may actually be up to ten times more of these earthworks in the region than I had previously imagined."

Aerial photo of earthworks at the Tequinho site in Acre, Brazil. The Aquiry culture is named for the word Indigenous peoples used for the Acre River, which flows from Peru and Bolivia to Acre, passing through the heart of the ancient civilization. 

(Martti Pärssinen, supplied)



The Aquiry civilization wasn't a single kingdom or empire, but a diverse network of communities connected by shared traditions.

We don't know much about them – they left no written records, and their dwellings are long gone.

What we do have are their monumental earthworks: geometric spaces delineated by ditches that could be meters deep, linked together by straight roads, where people may have gathered for ceremonies and political events.

Today, the geometric earthworks and the ecological legacy of their land management are among the few visible traces the Aquiry left behind.

"The scale of the archaeological record suggests that many other regions across Amazonia may have been far more densely populated and intensively modified than previously assumed." – archaeo-anthropologist Martti Pärssinen

In the centuries since their disappearance around 850 CE, the rainforest reclaimed much of what the Aquiry built. Hints of their structures emerged during land clearing, but the full scale remained lost beneath the trees.

LIDAR technology changed everything.

The technology fires laser pulses from an aircraft. Some penetrate gaps in the forest canopy and bounce off the ground, allowing researchers to reconstruct the hidden landscape beneath without disturbing the rainforest.

LIDAR images of earthworks. 

(Pärssinen et al., Nature, 2026)

The researchers surveyed 4,497 square kilometers (1,736 square miles) of rainforest by flying a series of long, roughly 450-kilometer (280-mile) transects over the region.

Their entire dataset yielded 432 earthworks – 396 of which were previously unknown.

"What surprised us most was the extraordinarily large number of geoglyphs and other earthworks found within an area representing less than 3 percent of Greater Amazonia," Pärssinen said.

"The scale of the archaeological record suggests that many other regions across Amazonia may have been far more densely populated and intensively modified than previously assumed."

By extrapolating their results, combined with existing surveys, the researchers estimated that, at its peak, the Aquiry civilization may have covered an area as large as 183,000 square kilometers.

This space could have supported a population of around 1.2 to 3 million people, in a landscape with as many as 24,000 to 30,000 earthworks, the researchers estimated.

It would have been a dramatically different place than the wilderness we see today – a forest threaded with clearings where people lived, farmed, celebrated, and gathered.

"At the center of many of these clearings would stand large geometric earthworks connected by broad and narrow roads," Pärssinen told ScienceAlert when asked what the landscape might have looked like around 200 CE.

"At certain times of the year, these places would come alive with ceremonies, gatherings, music, dancing, athletic competitions, and other communal events."

Aerial photo of earthworks at Piloto. 

(Martti Pärssinen, supplied)



With LIDAR uncovering the histories of many ancient societies in the Amazon, Pärssinen said the traditional view of the rainforest as an untouched wilderness should be "abandoned".

Instead, the new findings recast the Amazon as a rainforest shaped in many places by large human populations.

In their heyday, the Aquiry earthworks we see today would have likely been surrounded by "large wooden longhouses inhabited by substantial populations, alongside fields of maize, manioc, squash, and cotton," Pärssinen said.

"In the nearby forests, there would likely be an abundance of managed fruit- and nut-bearing trees, reflecting centuries of human stewardship of the landscape."

The discovery paints the clearest picture yet of the mysterious Aquiry and how they populated southwestern Amazonia for some 1,500 years. Much of their story, however, is still waiting to be told.

"Many questions remain unanswered," Pärssinen said.

"One of the most important is what happened between approximately [CE] 850 and 1000. Why did this civilization disappear?"

The birth of modern Man

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