Comment

Comment by Dr. Krishna Kumari Challa on August 15, 2026 at 10:51am

Cells use a little-known molecule to protect themselves from iron overload

Iron is essential. Our cells need it to produce energy, carry oxygen throughout the body and power countless chemical reactions that sustain life. But this metal has a dark side. When too much of it is left free inside cells, it can trigger destructive reactions that break down DNA, proteins and even cell membranes.
Now researchers have discovered that cells rely on an unexpected protector against this threat: small molecules called polyamines.

The researchers' detailed findings, published in the journal Cell, reveal that polyamines act like storage lockers for iron, safely holding the metal in a nonreactive state until cells need it.
These findings solve a decades-old mystery about why cells maintain such extraordinarily high levels of polyamines and uncover a previously unknown defense mechanism that protects cells from toxic iron overload.

This work could also help scientists develop better cancer treatments by allowing iron overload to trigger cancer cell death. It could also offer new clues about diseases like early-onset Parkinson's disease, in which mutations affect polyamine levels within neurons.

Polyamines buffer labile iron to suppress ferroptosis, Cell (2026). DOI: 10.1016/j.cell.2026.07.040. www.cell.com/cell/fulltext/S0092-8674(26)00872-X

Comment by Dr. Krishna Kumari Challa on August 15, 2026 at 10:38am

As the mice were learning this behavioral task, the researchers recorded their brain activity using miniaturized microendoscopes. These are ultrathin, lightweight imaging devices that can measure activity in hundreds of neurons simultaneously. The team observed activation patterns in the orbitofrontal cortex (OFC), a brain region involved in evaluating decisions guided by reward value.
The researchers chose to look at the orbitofrontal cortex because it has been shown to represent the value of options when humans and other animals are making decisions and previous experiments using mice had shown that it represents reward value that is signaled by odors in particular.
To understand how the brain represents the prospect of obtaining information, the researchers compared cases in which, based on the odor they sniffed, the mice expected to receive information with trials in which the reward outcome would remain unknown.

They identified a representation of the predicted value of information in the mouse orbitofrontal cortex.
Approximately 20% of the cells in the OFC showed different neural activity in response to odors that predicted information versus those that predicted no information, and the magnitude of that activity difference scaled with the duration of time the mice had knowledge of the reward outcome. This indicates that they identified a representation of information value that depended on its resolution of uncertainty, which is intrinsic to information and cognition.
The team's findings suggest that the mouse brain processes a desire for knowledge and the drive for physiological rewards differently.

The representation of the predicted value of information was discernible across the neural population in a way that was orthogonal to the representation of the predicted water value, which they observed in response to separate odors in their experiments. Given that they observed this pattern in the OFC, a brain area intimately involved in generating representations of the world to guide decisions, the representation of information value could be a critical signal that allows animals to take actions to gain information and increase their knowledge of the world.
The researchers pursued neural processes underlying curiosity and the drive to seek knowledge, with the goal that their work will also be applicable to humans.
Understanding how we evaluate sources of information and how wanting to gain knowledge drives our behaviour would have important implications for helping people navigate our information-rich modern world, including through learning during childhood development.
Not only could a better understanding of curiosity, the drive to gain information, improve people's success in learning, given the pleasurable, rewarding nature of acquiring knowledge, it could offer us access to more joy and fulfillment—something we all could use.

Jennifer J. Bussell et al, Representations of the intrinsic value of information in mouse orbitofrontal cortex, Nature Neuroscience (2026). DOI: 10.1038/s41593-026-02377-y.

Part 2

Comment by Dr. Krishna Kumari Challa on August 15, 2026 at 10:32am

Curiosity has its own neural signal: Brain separates valuable information from water rewards in mice
Often, humans and other animals seek information that can help them complete tasks and attain desired rewards. In some cases, however, they seek information driven simply by curiosity and a desire to obtain knowledge for its own sake, even if it does not lead to external rewards. Scientists know this better.
Researchers recently created a new experimental paradigm for studying the neural processes associated with curiosity and the desire for knowledge in mice. This paradigm, outlined in a paper in Nature Neuroscience, allowed them to gain new insights into how the brain represents the value of information regardless of physical rewards.
Previous studies offered some initial clues about how the mammalian brain attributes value to information. However, the process through which it recognizes stimuli that can provide interesting information and represents their value has not yet been elucidated.

This is a higher-order process of cognition, since what is most valuable as information depends on what we already know, and we can't detect and know how good information is by physiological processes in our body, the way we can with food or many other better understood types of reward that motivate our actions.
Researchers offered thirsty mice the choice of poking their noses into two holes.
One hole revealed with a short puff of odor whether they would receive a water reward, and the other revealed nothing but, critically, offered them the exact same chance and amount of water. Prior to making their decision, the mice had to poke in a third hole that presented them with an odor that either directed them to the information- or non-information-providing hole or offered them the choice. In this way, the mice learned that individual odors each predicted a certain amount of information or water reward.
Interestingly, the researchers observed that the mice predominantly preferred poking their noses into the hole that gave them information. This occurred even if the information-providing hole contained less water than the other hole. These findings suggest that mice are often willing to exchange water (i.e., a reward) for information. This, in turn, implies that the mice attribute value to the information itself.
Part 1

Comment by Dr. Krishna Kumari Challa on August 15, 2026 at 10:23am

AI agents struggle to perform original scientific research

Among the many predictions about the future of artificial intelligence is that models will one day be able to conduct scientific research on their own, leaving humans out of the equation. Already, they can write code, run experiments and search scientific literature, but carrying out open-ended research would require a significant leap in ability.
In a paper posted on the arXiv preprint server, researchers tested AI's ability to conduct open-ended research and found that it came up short.
The study authors gave frontier agents (cutting-edge, state-of-the-art AI tools designed to carry out complex, multi-step tasks autonomously) six days to conduct research and write papers based on two then-unpublished AI conference submissions. This ensured they couldn't just find the answers online.

The agents had full access to the internet, dedicated computing power and approximately $3,000 in model-use credits, meaning they had a budget to conduct open-ended exploration and run experiments. The topics they had to research and write about were the structure and controllability of language-model personas and designing a detector for distribution shifts in tabular foundation models.

Once the six days were up, human researchers reviewed the AI-written papers and graded them as they would papers submitted to a top-tier AI conference.

The frontier agents did not do well at all. Both papers received unambiguous rejection scores (2/6 and 1/6 overall) from the expert human reviewers. Although the AI understood the research questions and proposed some directions that closely mirrored those of the original researchers, its scientific reasoning suffered from major flaws. Experimental designs were weak, and the agents handled negative feedback poorly, often adding caveats to existing findings rather than redesigning their studies.

They also managed their time poorly and spent less than half of their allocated API budget. Despite having time, they rushed through their work and submitted papers that fell far short of publishable standards.

The reviewers did not hold back on their assessments of the agents:

"The experiments and methodological choices were bizarre and hard to understand. The results seem clearly a result of post hoc choices."—David Africa, expert reviewer.
"Upon testing a few unsuccessful signals using a PFN's internals, going from there to 'there are no signals we can use that leverage a model's internals' is a huge leap, a kind of 'proof by example' fallacy that is highly non-scientific."—Viet Nguyen, expert reviewer.
While these results are a sobering reality check on AI's ability to perform scientific research, they do not mean models have no place in the lab. In the near term, they are more likely to serve as assistants handling routine tasks rather than being deeply involved in the process of discovery.

Peter Kirgis et al, Can AI agents conduct open-ended AI research? Early evidence from two case studies, arXiv (2026). DOI: 10.48550/arxiv.2607.27191

Comment by Dr. Krishna Kumari Challa on August 14, 2026 at 11:12am

Fridge-free vaccines

Scientists have successfully trialled vaccines that do not need to be refrigerated or frozen, which could slash the number of vaccine doses that are wasted each year. Sixty volunteers received a tetanus-diphtheria vaccine that had been kept as a dry powder for a year at room temperature before it was dissolved and injected. The jab was “safe and well tolerated” and gave “equivalent” immune responses to the conventional vaccine. The team will launch a larger trial of 160 people in the coming months.

https://www.thelancet.com/journals/eclinm/article/PIIS2589-5370(26)00369-X/fulltext?utm_source=Live+Audience&utm_campaign=e2b449d6f7-nature-briefing-translational-research-20260812&utm_medium=email&utm_term=0_-928f7c52f0-50323416

Comment by Dr. Krishna Kumari Challa on August 14, 2026 at 10:28am

Fungal age remains elusive as underground networks continually grow, split and recycle
Fungal age is difficult to define because mycelial networks continually grow, recycle tissue and fragment into genetically identical units. Longevity likely varies among species and lifestyles, requiring genetic tracking, long-term experiments and microfluidic systems to characterize persistence and life cycles.

Exploring the concept of longevity in fungi, Trends in Microbiology (2026). DOI: 10.1016/j.tim.2026.07.001

Comment by Dr. Krishna Kumari Challa on August 14, 2026 at 9:33am

Nature's original bioplastic may have fed animals for hundreds of millions of years

Long before humans discovered biodegradable plastics, microorganisms had already invented their own. Many bacteria and archaea produce natural bioplastics called polyhydroxyalkanoates (PHAs), storing them inside their cells as reserves of carbon and energy.
Until now, scientists thought that only microorganisms themselves could break down these substances. Researchers at the Max Planck Institute for Marine Microbiology in Bremen, Germany, have now overturned that long-standing assumption.

In a study published in Nature Ecology & Evolution, they show that animals ranging from marine worms and starfish to terrestrial species, including earthworms, have enzymes capable of degrading microbial PHAs. The findings reveal a previously overlooked way in which microbial carbon can enter animal food webs.
Microbial PHAs occur naturally in soils, sediments and aquatic environments worldwide. They are produced whenever microorganisms store excess carbon for later use and are among the few naturally occurring plastics that are completely biodegradable. Because PHAs are increasingly manufactured as sustainable alternatives to conventional plastics, understanding how they are degraded in nature has become an important area of research.
The new findings suggest that animals, together with microorganisms, may contribute to the breakdown of these natural bioplastics. More fundamentally, they reveal that animals can exploit a microbial carbon reserve that had previously been thought to be inaccessible to them.

Animal degradation of microbial storage polyhydroxyalkanoates, Nature Ecology & Evolution (2026). DOI: 10.1038/s41559-026-03153-8

**

Comment by Dr. Krishna Kumari Challa on August 14, 2026 at 9:20am

A 236-million-year-old fossil challenges the story of mammalian live birth

Some cynodonts may have been giving birth to live young much sooner in evolutionary history than previously assumed. A new Frontiers in Mammal Science study has offered the first compelling evidence that cynodonts may have been viviparous—a reproductive mode characterized by live birth.

Researchers showed for the first time that live birth was present in at least one mammalian ancestor, Chiniquodon theotonicus, which lived approximately 236 million years ago. This implies that viviparity among early cynodonts originated in the mammalian lineage at least 95 to 90 million years earlier than previously thought.

Cynodonts thrived in the Triassic, a period of recovery and restructuring of ecosystems after one of the most devastating mass extinctions in life history. This meant high competition for resources and strong predatory pressures. Combined with a trend toward aridity and strong seasonality, embryos of viviparous species would be better protected than those of egg-laying species.

Until now, giving birth to live young was considered a relatively modern evolutionary acquisition in the mammalian lineage. The finding raises questions about which other traits believed to have appeared much later were already present among cynodonts, the researchers say.

Early Origin of Viviparity in the Mammalian Lineage, Frontiers in Mammal Science (2026). DOI: 10.3389/fmamm.2026.1845319

Comment by Dr. Krishna Kumari Challa on August 13, 2026 at 12:03pm

Female gut muscles reshape to meet the demands of reproduction, preclinical study suggests

Organs don't just grow in early life; they can change in response to physiological or environmental challenges in adulthood. Researchers have now identified an active role for the intestinal muscles in remodelling the gut after reproduction.
Reproduction remodels intestinal smooth muscle in female fruit flies and mice, elongating contractile filaments without increasing cell number and reducing contractility. In flies, mating lowers juvenile hormone receptor signalling in muscle, permitting growth, while epithelial growth is promoted by the same hormone. These changes may enhance nutrient absorption during reproduction.

Alessandro Mineo et al, The sex and reproductive plasticity of intestinal muscles instruct gut size, Cell (2026). DOI: 10.1016/j.cell.2026.07.024

Comment by Dr. Krishna Kumari Challa on August 13, 2026 at 11:26am

For decades we have known that rheumatoid arthritis selectively targets particular joints, but one of the great unanswered questions is why?
These new findings suggest that the answer lies not only in the immune system but also in the tissues themselves. The cellular and structural characteristics established during development may help determine where inflammation takes hold later in life.
Researchers found that the developing joints were made up mainly of structural cells, including cartilage-forming cells and fibroblasts, rather than immune cells. They then investigated what drives these cells to develop into their different specialized forms.

One population that drew particular attention was the synovial lining fibroblasts. These cells produce substances that lubricate the joint to help protect and maintain smooth movement, yet they can also behave abnormally in arthritis. Further analysis suggested that the lining may come from two different sources, both the cartilage and surrounding joint fibroblasts.

The process appeared to be influenced by specific localized signals such as low oxygen levels. This may provide insights into the mechanisms driving their function and help identify ways to restore their normal protective role in disease.
The researchers found important differences between the PIP and DIP joints. A bespoke image analysis tool showed that PI16+ fibroblasts that were enriched in the PIP joints were specifically located around blood vessels and at sites where tendons and ligaments connect with surrounding tissue.

They also showed that PI16+ fibroblasts responded differently to inflammatory signals compared with other fibroblast populations. While PI16+ fibroblasts shared a common pro-inflammatory response with PI16- fibroblasts, they also displayed distinct changes in pathways linked to tissue organization and immune regulation.

The team also identified striking structural differences between the joints. Using high-resolution 3D imaging at Diamond Light Source at the Harwell Science and Innovation Campus, they found that the synovial tissue surrounding PIP joints was larger and organized differently from that seen in joints that are not usually affected by rheumatoid arthritis. Together, these cellular and structural differences may help explain why inflammation develops in some locations but not others.
Together, the findings suggest that the tendency of rheumatoid arthritis to affect particular joints may be shaped by tissue architecture established during development. Rather than being determined by immune activity alone, vulnerability to inflammation may depend on the local cellular and structural environment of each joint.

Sarah Davidson et al, The embryonic origins of site-specific arthritis, Nature Immunology (2026). DOI: 10.1038/s41590-026-02542-2

• ‹ Previous
• 1
• …
• 13
• 14
• 15
• 16
• 17
• …
• 1293
• Next ›
• Page