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Comment by Dr. Krishna Kumari Challa 47 minutes ago

Comment by Dr. Krishna Kumari Challa 57 minutes ago

Scientists shoot lasers into brain cells to uncover how illusions work

An illusion is when we see and perceive an object that doesn't match the sensory input that reaches our eyes.

In a new study published in Nature Neuroscience, researchers identified the key neural circuit and cell type that plays a pivotal role in detecting these illusions—more specifically, their outer edges or "contours"—and how this circuit works.

They discovered a special group of cells called IC–encoder neurons that tell the brain to see things that aren't really there as part of a process called recurrent pattern completion.

Because IC–encoder neurons have this unique capacity to drive pattern completion, the researchers think that they might have specialized synaptic output connectivity that allows them to recreate this pattern in a very effective manner.

They also also know that they receive top-down inputs from higher visual areas. The representation of the illusion arises in higher visual areas first and then gets fed back to the primary visual cortex; and when that information is fed back, it's received by these IC–encoders in the primary visual cortex.

 In the context of the brain and vision—using the above shape diagram—higher levels of the brain interpret the image as a square and then tell the lower-level visual cortex to "see a square" even though the visual stimulus consists of four semi-complete black circles.

They made the discovery by observing the electrical brain activity patterns of mice when they were shown illusory images like the Kanizsa triangle. They then shot beams of light at the IC-encoder neurons, in a process called two-photon holographic optogenetics, when there was no illusory image present.

When this happened, they noticed that even in the absence of an illusion, IC-encoder neurons triggered the same brain activity patterns that exist when an illusory image was present. They successfully emulated the same brain activity by stimulating these specialized neurons.

The findings shed light on how the visual system and perception work in the brain and have implications for diseases where this system malfunctions. In certain diseases you have patterns of activity that emerge in your brain that are abnormal, and in schizophrenia these are related to object representations that pop up randomly.

If you don't understand how those objects are formed and a collective set of cells work together to make those representations emerge, you're not going to be able to treat it; so understanding which cells and in which layer this activity occurs is helpful.

Recurrent pattern completion drives the neocortical representation of sensory inference, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02055-5.

Comment by Dr. Krishna Kumari Challa 1 hour ago

A second study published in Proceedings of the National Academy of Sciences examined the human P2X2 receptor, a protein in the same family as the P2X7 receptor, but is predominantly found in the cochlea, the hearing organ of the inner ear.

The P2X2 receptor is involved in hearing processes and in the ear's adaptation to loud noise. Certain genetic mutations of this receptor have been linked to hearing loss. Currently, there are no drugs that target this receptor effectively, and until now, scientists had limited insight into how it functions.

Researchers  used cryo-electron microscopy—a powerful imaging method—to capture 3D structures of the human P2X2 receptor in two states: in a resting state and in a state bound to ATP but desensitized, meaning it's not active anymore. The team discovered unique structural features and pinpointed areas where hearing-related mutations occur.

Together, the studies mark a leap forward in understanding how P2X receptors contribute to a wide range of diseases by triggering inflammation and sensory changes.

Adam C. Oken et al, A polycyclic scaffold identified by structure-based drug design effectively inhibits the human P2X7 receptor, Nature Communications (2025). DOI: 10.1038/s41467-025-62643-8

Franka G. Westermann et al, Subtype-specific structural features of the hearing loss–associated human P2X2 receptor, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2417753122

Part2

 

Comment by Dr. Krishna Kumari Challa 1 hour ago

Scientists uncover how cellular receptors trigger inflammation and sensory changes

In two new studies, scientists have uncovered detailed blueprints of how certain molecular "gates" in human cells work—findings that could open doors to new treatments for conditions ranging from certain cancers and brain diseases to hearing loss and atherosclerosis, or plaque build-up in the arteries.

They studied a group of proteins known as P2X receptors, which sit on the surface of cells and detect ATP—a molecule best known as the body's energy source inside of cells.

When ATP leaks outside of cells, often as a sign of stress or damage, P2X receptors act like alarm bells, triggering responses related to inflammation, pain and sensory processing.

Extracellular ATP is a universal danger signal. When it builds up outside cells, P2X receptors sense it and change how the cells respond. Understanding these receptors at the atomic level is key to designing drugs that can either calm them down or fine-tune their activity.

In a study published in Nature Communications, researchers examined the molecular structure of the human P2X7 receptor, a protein linked to inflammatory diseases such as cancer, Alzheimer's and atherosclerosis. Despite years of effort, no drugs targeting P2X7 have reached the clinical market, partly because drugs that have worked well in animal models have not had the same success in humans.

Building on a previous study, where they determined how to turn the rat P2X7 receptor off, the team has now mapped how drugs turn off the human P2X7 receptor for the first time. They now know what makes the human receptor different from the receptor that is present in animal models. This is important for understanding how to better customize drugs to fit the binding pockets within the human receptor.

Using that information, the researchers, in collaboration with groups from around the world, designed a new compound referred to as UB-MBX-46. The compound complements the binding pocket in the human receptor, translating to a molecule that blocks the human receptor with high precision and strength.

This is the first time scientists have visualized the human P2X7 receptor and really understood how it is different from others. With that knowledge, they can now create a drug candidate that perfectly fits binding pockets within the human receptor, much like how a key fits in a lock. It gives us hope for developing therapies that have better chances to reach the clinic.

Part 1

Comment by Dr. Krishna Kumari Challa 2 hours ago

In the history of evolution, life sometimes undergoes transitions which change what it means to be an individual. This happened when single cells evolved to become multicellular organisms and social insects evolved into ultra-cooperative colonies. These individuality transitions transform how life is organized, adapts and reproduces. Biologists have been skeptical that such a transition is occurring in humans.

But the researchers suggest that because culture is fundamentally shared, our shift to cultural adaptation also means a fundamental reorganization of human individuality—toward the group.
Cultural organization makes groups more cooperative and effective. And larger, more capable groups adapt—via cultural change—more rapidly. It's a mutually reinforcing system, and the data suggest it is accelerating.
For example, genetic engineering is a form of cultural control of genetic material, but genetic engineering requires a large, complex society. So, in the far future, if the hypothesized transition ever comes to completion, our descendants may no longer be genetically evolving individuals, but societal "superorganisms" that evolve primarily via cultural change.
The researchers emphasize that their theory is testable and lay out a system for measuring how fast the transition is happening. The team is also developing mathematical and computer models of the process and plans to initiate a long-term data collection project in the near future. They caution, however, against treating cultural evolution as progress or inevitability.
They are not suggesting that some societies, like those with more wealth or better technology, are morally 'better' than others. Evolution can create both good solutions and brutal outcomes. They think this might help our whole species avoid the most brutal parts.
The goal of this work goal is to use their understanding of deep patterns in human evolution to foster positive social change.
Still, the new research raises profound questions about humanity's future. "If cultural inheritance continues to dominate, our fates as individuals, and the future of our species, may increasingly hinge on the strength and adaptability of our societies.
And if so, the next stage of human evolution may not be written in DNA, but in the shared stories, systems, and institutions we create together, the researchers conclude.

Timothy M Waring et al, Cultural inheritance is driving a transition in human evolution, BioScience (2025). DOI: 10.1093/biosci/biaf094. academic.oup.com/bioscience/ad … osci/biaf094/8230384

Part 2

Comment by Dr. Krishna Kumari Challa 2 hours ago

Culture is overtaking genetics in shaping human evolution, researchers argue

Some Researchers are theorizing that human beings may be in the midst of a major evolutionary shift—driven not by genes, but by culture.

In a paper published in BioScience, they argue that culture is overtaking genetics as the main force shaping human evolution.

"When we learn useful skills, institutions or technologies from each other, we are inheriting adaptive cultural practices. On reviewing the evidence, we find that culture solves problems much more rapidly than genetic evolution. This suggests our species is in the middle of a great evolutionary transition", they say.

Cultural practices—from farming methods to legal codes—spread and adapt far faster than genes can, allowing human groups to adapt to new environments and solve novel problems in ways biology alone could never match. According to the research team, this long-term evolutionary transition extends deep into the past, it is accelerating, and may define our species for millennia to come.

Cultural evolution eats genetic evolution for breakfast, they argue. 

 In the modern environment cultural systems adapt so rapidly they routinely "preempt" genetic adaptation. For example, eyeglasses and surgery correct vision problems that genes once left to natural selection.

Medical technologies like cesarean sections or fertility treatments allow people to survive and reproduce in circumstances that once would have been fatal or sterile. These cultural solutions, researchers argue, reduce the role of genetic adaptation and increase our reliance on cultural systems such as hospitals, schools and governments.

Today, your well-being is determined less and less by your personal biology and more and more by the cultural systems that surround you—your community, your nation, your technologies. And the importance of culture tends to grow over the long term because culture accumulates adaptive solutions more rapidly.

Over time, this dynamic could mean that human survival and reproduction depend less on individual genetic traits and more on the health of societies and their cultural infrastructure.

But, this transition comes with a twist. Because culture is fundamentally a shared phenomenon, culture tends to generate group-based solutions.

Using evidence from anthropology, biology and history, Waring and Wood argue that group-level cultural adaptation has been shaping human societies for millennia, from the spread of agriculture to the rise of modern states. They note that today, improvements in health, longevity and survival reliably come from group-level cultural systems like scientific medicine and hospitals, sanitation infrastructure and education systems rather than individual intelligence or genetic change.
The researchers argue that if humans are evolving to rely on cultural adaptation, we are also evolving to become more group-oriented and group-dependent, signaling a change in what it means to be human.
Part1

Comment by Dr. Krishna Kumari Challa 2 hours ago

Ants defend plants from herbivores, but can hinder pollination by bees

Around 4,000 plant species from different parts of the world secrete nectar outside their flowers, such as on their stems or leaves, through secretory glands known as extrafloral nectaries. Unlike floral nectar, extrafloral nectar does not attract pollinators; rather, it attracts insects that defend plants, such as ants. These insects feed on the sweet liquid and, in return, protect the plant from herbivores. However, this protection comes at a cost.

A study published in the Journal of Ecology points out that the presence of ants can reduce the frequency and duration that bees visit the flowers of plants with extrafloral nectaries.

Pollination is only impaired when extrafloral nectaries are close to the flowers. Plants with these glands in other locations, such as on their leaves or branches, had increased reproductive success, likely due to the protection against herbivores provided by ants.

On the other hand, butterflies, another group of pollinators, are not affected by ants. This may be due to the way these two groups feed. Butterflies use a long, straw-like organ called a proboscis to suck nectar from a distance, keeping them safe from ants.

Bees, on the other hand, need to get very close to the flower to collect pollen and floral nectar, but ants don't allow them to stay for long. Not surprisingly, the new analysis showed that the presence of ants is detrimental to pollination when extrafloral nectaries are close to flowers, but has a positive effect on plant reproduction when they're located further away.

The conclusions are the result of an analysis of data from 27 empirical studies on the relationships between ants, pollinators, and plants with extrafloral nectaries. The articles were selected from an initial screening of 567 studies after applying inclusion and exclusion criteria. The data were compiled and analyzed with computational tools.

Amanda Vieira da Silva et al, Ants on flowers: Protective ants impose a low but variable cost to pollination, moderated by location of extrafloral nectaries and type of flower visitor, Journal of Ecology (2025). DOI: 10.1111/1365-2745.70087

Comment by Dr. Krishna Kumari Challa 2 hours ago

The death of the dinosaurs reengineered Earth

Dinosaurs had such an immense impact on Earth that their sudden extinction led to wide-scale changes in landscapes—including the shape of rivers—and these changes are reflected in the geologic record, according to a new study.

Scientists have long recognized the stark difference in rock formations from just before dinosaurs went extinct to just after, but chalked it up to sea level rise, coincidence, or other abiotic reasons. But the new study shows that once dinosaurs were extinguished, forests were allowed to flourish, which had a strong impact on rivers.

Studying these rock layers, the researchers suggest that dinosaurs were likely enormous "ecosystem engineers," knocking down much of the available vegetation and keeping land between trees open and weedy. The result was rivers that spilled openly, without wide meanders, across landscapes. Once the dinosaurs perished, forests were allowed to flourish, helping stabilize sediment and corralling water into rivers with broad meanders.

Their results, published in the journal Communications Earth & Environment, demonstrate how rapidly the Earth can change in response to catastrophic events.

Very often when we're thinking about how life has changed through time and how environments change through time, it's usually that the climate changes and, therefore, it has a specific effect on life, or this mountain has grown and, therefore, it has a specific effect on life. It's rarely thought that life itself could actually alter the climate and the landscape. The arrow doesn't just go in one direction, the researchers say.

 Dinosaur extinction can explain continental facies shifts at the Cretaceous-Paleogene boundary, Communications Earth & Environment (2025). DOI: 10.1038/s43247-025-02673-8

Comment by Dr. Krishna Kumari Challa 2 hours ago

Scientists discover how nanoplastics disrupt brain energy metabolism

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

The study has revealed the specific mechanism by which these tiny nanoplastics can interfere with energy production in the brain in an animal model. The findings, recently published in the Journal of Hazardous Materials: Plastics, provide fresh insights into the potential health risks posed by environmental plastics.

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

The researchers focused on mitochondria, which are critical for producing the energy needed for brain function. Mitochondrial dysfunction is a well-known feature of neurodegenerative diseases such as Parkinson's and Alzheimer's, as well as normal aging.

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

The scientists found that electron transfer between complex I–III and complex II–III was potently inhibited at much lower concentrations, suggesting environmentally relevant exposures could also impair bioenergetic function over chronic timeframes.

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

D.M. Seward et al, Polystyrene nanoplastics target electron transport chain complexes in brain mitochondria, Journal of Hazardous Materials: Plastics (2025). DOI: 10.1016/j.hazmp.2025.100003

Comment by Dr. Krishna Kumari Challa 3 hours ago

Scientists engineer plants to double carbon uptake ability and produce more seeds and lipids

Typically, plants rely on the Calvin-Benson-Bassham (CBB) cycle to convert carbon dioxide in the atmosphere to usable organic matter for growth. Although this cycle is the main pathway for carbon fixation in all plants on Earth, it is surprisingly inefficient—losing one third of carbon in the cycle when synthesizing the molecule acetyl–coenzyme A (CoA) to generate lipids, phytohormones, and metabolites. Plants also lose carbon during photorespiration, which limits their growth. This is largely due to the inefficiency of an enzyme called RuBisCO.

In efforts to increase carbon uptake and reduce carbon loss in plants to boost biomass and lipid production, scientists have experimented with ways to increase the efficiency of RuBisCO, overexpress CBB cycle enzymes, introduce carbon-concentrating mechanisms, and reduce photorespiration losses. But, a new study published in Science, focuses on a novel approach—creating an altogether new pathway for carbon uptake.

The researchers involved in the study introduced a synthetic CO₂ uptake cycle into the plant Arabidopsis thaliana. They refer to the engineered cycle as the malyl-CoA-glycerate (McG) cycle, which works in conjunction with the CBB cycle to create a dual-cycle CO₂ fixation system. The new cycle increases efficiency by using previously wasted carbon.

"In the McG cycle, one additional carbon is fixed when 3PG is the input, or no carbon is lost when glycolate is the input. In both cases, acetyl-CoA is produced more efficiently, which is expected to enhance the production of lipids and other important plant metabolites, including phytohormones," the authors write.

 Kuan-Jen Lu et al, Dual-cycle CO₂ fixation enhances growth and lipid synthesis in Arabidopsis thaliana, Science (2025). DOI: 10.1126/science.adp3528

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