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Comment by Dr. Krishna Kumari Challa 11 hours ago

Men’s brains shrink more with age
Men’s brains shrink more as they age than women’s brains do, which could scupper the theory that age-related brain changes explain why women are more frequently diagnosed with Alzheimer’s disease than men. Using more than 12,500 brain scans from 4,726 people, researchers found that men experienced a greater reduction in volume across more regions of the brain over time than women did. This suggests that sex differences in brain volume don’t play a part in the development of Alzheimer’s, but “just looking at age-related changes in brain atrophy is unlikely to explain the complexities behind [the disease]”, say neurophysiologists.

 Proceedings of the National Academy of Sciences paper

https://www.pnas.org/doi/10.1073/pnas.2510486122

https://www.nature.com/articles/d41586-025-03353-5?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa 12 hours ago

Fetal hearing begins to develop a little more than halfway through pregnancy, around 24 weeks into what is normally a 40-week gestation period. As the fetus grows, the uterus expands and the uterine wall thins.

Late in pregnancy, more sounds, including the mother's conversations, reach the fetus. At birth, full-term newborns recognize their mother's voice and prefer the sounds of their parents' native language to other languages, prior research has shown.

These factors suggest that listening to Mom's voice contributes to brain maturation in the latter half of a full-term pregnancy.

So in their work the researchers realized that by supplementing the sounds that premature babies hear in the hospital so they resemble what they would have heard in the womb, they had a unique opportunity to possibly improve brain development at this stage of life.

 Listening to Mom in the Neonatal Intensive Care Unit: A randomized trial of increased maternal speech exposure on white matter connectivity in infants born preterm, Frontiers in Human Neuroscience (2025). DOI: 10.3389/fnhum.2025.1673471

Part 2

Comment by Dr. Krishna Kumari Challa 12 hours ago

Mom's voice boosts language-center development in preemies' brains, study finds

Hearing the sound of their mother's voice promotes development of language pathways in a premature baby's brain, according to a new  study.

During the study, which is published in Frontiers in Human Neuroscience, hospitalized preemies regularly heard recordings of their mothers reading to them. At the end of the study, MRI brain scans showed that a key language pathway was more mature than that of preemies in a control group who did not hear the recordings. It is the first randomized controlled trial of such an intervention in early development.

This is the first causal evidence that a speech experience is contributing to brain development at this very young age.

Premature babies—born at least three weeks early—often spend weeks or months in the hospital, typically going home around their original due dates. During hospitalization, they hear less maternal speech than if they had continued to develop in utero.

Parents can't usually stay at the hospital around the clock; they may have older children to care for or jobs they must return to, for example. Preemies are at risk for language delays, and scientists have suspected that reduced early-life exposure to the sounds of speech contributes to the problem.

The researchers decided to boost preemies' exposure to their mom's voices during hospitalization. They did this by playing recordings of the mothers speaking, a total of two hours and 40 minutes a day, for a few weeks at the end of the babies' hospital stays.

Babies were exposed to this intervention for a relatively short time. In spite of that, researchers saw very measurable differences in their language tracts. It's powerful that something fairly small seems to make a big difference.

Part 1

Comment by Dr. Krishna Kumari Challa 12 hours ago

A neural basis for flocking

When animals move together in flocks, herds, or schools, neural dynamics in their brain become synchronized through shared ways of representing space, a new study by researchers  suggests. The findings challenge the conventional view of how collective motion arises in nature.

Flocking animals, such as hundreds of birds sweeping across the sky in unison, are a mesmerizing sight. But how does their collective motion—seen in many species, from swarming locusts to schooling fish and flocking birds—arise?

Researchers have developed a novel theoretical framework that integrates neurobiological principles to upend long-held assumptions about how flocking behavior emerges in nature.

In a recent article published in Nature Communications they demonstrate that flocking does not require individuals to rely on rigid behavioral rules, as is typically assumed. Instead, it can arise naturally from a simple and widespread neural architecture found across the animal kingdom: the ring attractor network.

In the new model, flocking arises because neural activity in each animal becomes linked through perception: Every individual processes its surroundings using a ring attractor—a circular network of neurons that tracks the direction toward perceived objects in space. This way, the animal can maintain bearings toward others relative to stable features in the environment. The researchers found that when many such individuals interact, their neural dynamics synchronize, giving rise to spontaneous alignment and collective movement.

This means that coordinated motion can emerge directly from navigational processes in the brain, challenging decades of theory.

The new framework shows that collective motion emerges when individuals represent the directions of others relative to stable features in their surroundings—a world-centered, or allocentric, perspective. This mechanism underlies what the authors describe as "allocentric flocking."

Mohammad Salahshour et al, Allocentric flocking, Nature Communications (2025). DOI: 10.1038/s41467-025-64676-5

Comment by Dr. Krishna Kumari Challa 12 hours ago

New lab-grown human embryo model produces blood cells

Scientists have used human stem cells to create three-dimensional embryo-like structures that replicate certain aspects of very early human development—including the production of blood stem cells. The findings are published in the journal Cell Reports.

Human blood stem cells, also known as hematopoietic stem cells, are immature cells that can develop into any type of blood cell, including red blood cells that carry oxygen and various types of white blood cells crucial to the immune system.

The embryo-like structures, which the scientists have named "hematoids," are self-organizing and start producing blood after around two weeks of development in the lab—mimicking the development process in human embryos.

The structures differ from real human embryos in many ways, and cannot develop into them because they lack several embryonic tissues, as well as the supporting yolk sac and placenta needed for further development.

Hematoids hold exciting potential for a better understanding of blood formation during early human development, simulating blood disorders like leukemia, and for producing long-lasting blood stem cells for transplants.

The human stem cells used to derive hematoids can be created from any cell in the body. This means the approach also holds great potential for personalized medicine in the future, by allowing the production of blood that is fully compatible with a patient's own body.

A post-implantation model of human embryo development includes a definitive hematopoietic niche, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.116373. www.cell.com/cell-reports/full … 2211-1247(25)01144-1

Comment by Dr. Krishna Kumari Challa 12 hours ago

Flipping the switch on sperm motility offers new hope for male infertility

Infertility affects about one in six couples, and male factors account for roughly half of all cases—often because sperm don't swim well. Researchers have uncovered a key component of the "switch" that keeps the movement signal strong, offering a promising new avenue for both diagnosis and treatment. When this switch is absent, sperm slow down, and fertilization fails. By restoring that signal in the lab, the team rescued swimming and achieved healthy births in mice.

The study has been published in Proceedings of the National Academy of Sciences.

For sperm to successfully fertilize an egg, they must be able to swim, a process driven by their tail. This movement is activated by an essential signaling molecule called cyclic AMP (cAMP). While it was known that an enzyme named soluble adenylyl cyclase (sAC) produces cAMP inside sperm, the precise mechanism controlling this enzyme's stability and function remained largely a mystery.

The study focused on a protein with a previously unknown function, TMEM217, which is produced specifically in the testes. They engineered mice that could not produce TMEM217 and found that the males were completely infertile, with sperm that were almost entirely immotile. Further investigation revealed that TMEM217 partners with another protein, SLC9C1, to form a stable complex.

This complex is crucial for maintaining the presence of the sAC in mature sperm. Without TMEM217, SLC9C1 is lost and sAC is markedly reduced, causing cAMP levels to plummet and sperm motility to fail.  

In a significant breakthrough, the team took the immotile sperm from these mice and treated them with a cAMP analog—a molecule that mimics cAMP. This treatment successfully restored the sperm's movement and enabled them to fertilize eggs in vitro, leading to the birth of healthy pups.

The study has revealed a fundamental "switch" in sperm, providing a deeper understanding of sperm motility regulation. The discovery of the TMEM217-SLC9C1-sAC axis offers a new target for diagnosing unexplained cases of male infertility.

Formation of a complex between TMEM217 and the sodium-proton exchanger SLC9C1 is crucial for mouse sperm motility and male fertility, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2516573122

Comment by Dr. Krishna Kumari Challa 12 hours ago

Rewriting the rules of genetics: Study reveals gene boundaries are dynamic, not fixed

Molecular biologists have long thought that the beginning of a gene launched the process of transcription—the process by which a segment of DNA is copied into RNA and then RNA helps make the proteins that cells need to function.

But a new study published in Science by researchers challenges that understanding, revealing that the beginning and end of genes are not fixed points, but move together—reshaping how cells build proteins and adapt through evolution.

This work rewrites a textbook idea: the beginning of a gene doesn't just launch transcription—it helps decide where it stops and what protein you ultimately make. 

For years, we taught that a gene's 'start' only decides where transcription begins. We now show the start also helps set the finish line—gene beginnings control gene endings, say the researchers  of this new work.

The discovery offers a promising new strategy for targeting cancer and neurological disorders, as well as developmental delays and aging. When gene transcription is disrupted or misregulated, protein production can become abnormal, potentially causing tumor growth.

The understanding that the beginning and ends of genes are connected could allow physicians to redirect gene expression—restoring healthy protein variants and suppressing harmful ones, without altering the underlying DNA sequence.

Misplacing a start or an end isn't a small mistake—it can flip a protein's domain structure and change its function, too. In cancer, that flip can mean turning a tumor suppressor into an oncogene. An oncogene is a mutated gene that has the potential to cause cancer by promoting uncontrolled cell growth and division.

These new findings show that controlling where a gene begins is a powerful way to control where it ends—and, ultimately, what a cell can do. 

Ezequiel Calvo-Roitberg et al, mRNA initiation and termination are spatially coordinated, Science (2025). DOI: 10.1126/science.ado8279

Comment by Dr. Krishna Kumari Challa yesterday

Do plastics have toxic effects on the heart? Higher exposure linked to changes in heart rhythms

We've all heard warnings about BPA—a chemical found in plastics and personal care products. Studies show that nearly millions of people around the world have detectable levels of BPA in their bodies. Now, new research has revealed this everyday exposure is tied to changes in the heart's electrical system.

Phenols are a wide variety of chemicals. The best-known example is BPA.

BPA can be found in water bottles, food can linings, cash register receipts, eyeglass lenses, even baby bottles and makeup. These are environmental phenols—chemicals in products we touch every day.

 So researchers studied 600 people. Urine tests and EKGs found higher exposure was linked to changes in heart rhythms.

The electrical conduction literally keeps us alive. If it gets altered in any way, you could die immediately, say cardiologists.

Healthy individuals should not be affected by this. But if you find a person that's genetically predisposed, that is older, these can lead to potential changes.

https://www.uc.edu/news/articles/2025/10/do-plastics-have-toxic-eff...

Comment by Dr. Krishna Kumari Challa yesterday

Nanoplastics detected in farm animal cells: Study warns of possible human consequences

Scientists at the Research Institute for Farm Animal Biology (FBN) in Dummerstorf and the University of Udine have detected the uptake of nanoplastics in farm animal cell cultures. The results provide evidence of potential risks to animal health, meat production and also human food safety.

Plastic bags, packaging, yogurt lids—items that are carelessly thrown away decompose over years into tiny plastic particles. They end up in soil, waterways and ultimately in our food chain. Although numerous studies have already shown that microplastics can harm marine animals, birds and insects, the effects of nanoplastics on livestock have hardly been researched to date.

Unlike microplastics (1 µm–5 mm), there are currently few adequate methods for detecting nanoplastics (< 1 µm) in humans and animals. However, researchers assume that these small particles can also accumulate in tissue.

In a new study, researchers have demonstrated the uptake of nanoplastic particles made of polystyrene into cultured cells from cattle and pigs. This absorption led to changes that could impair the cell function and health of the animals in the long term.

The study examined granulosa cells from cattle, which play an important role in reproduction, and myoblasts from pigs, which are used to form muscle tissue. Even low concentrations led to microscopically visible accumulations. These could impair the fertility of the animals and their products.
Farm animals are part of the human food chain. Direct health risks to consumers cannot be inferred at present. Nevertheless, the researchers urge for more detailed investigations into the long-term consequences of microplastics and nanoplastics.

Francesca Corte Pause et al, Exploring the influence of polystyrene-nanoplastics on two distinct in vitro systems in farm animals: A pilot study, Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2025.179378

Comment by Dr. Krishna Kumari Challa yesterday

The migration period has started. Millions of birds are migrating now.

But birds face a variety of threats during migration—collisions with windows, communications towers and wind turbines; light pollution that disorients them; habitat loss or degradation in their migration stopover areas; human disturbance while feeding at stopover areas; predators; and storms.

Artificial light is one of the biggest dangers for birds traveling at night. It can confuse or attract them toward buildings, where they may crash into windows.

Birds collide with windows when they can't see them or, even worse, are attracted to them because of reflections of plants or the sky.This happens during the day, as well as at night during migration when lights disorient birds or if fog is causing them to fly low.

That's why people have an important role to play, say experts. The three most important things you can do for birds this time of year are to keep cats indoors, turn your lights off and use window mitigation.

Turn off unnecessary outdoor lighting at night or use motion sensors and timers so lights are only on when needed. If you must leave a light on, use warm-colored lights with shields that face downward.

Homeowners can also help reduce window collisions by: Placing bird feeders within three feet of windows or more than 30 feet away

Using window screens, UV tape or hanging cords to make glass visible

Closing blinds to limit reflections

Leaving fallen logs or stick piles in yards to give birds shelter as they stop to rest.

Enjoy these visitors as they pass through. But feed responsibly! Clean your feeders regularly, follow window guidance, and keep your cats indoors.

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