Comment

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:19am

Why watching someone get hurt on screen makes you wince: How the brain triggers echoes of touch sensation

Many people say that seeing bodily injury on film makes them flinch, as if they "feel" it themselves. It is as if the sting leaps straight off the screen and into your skin. 

But explaining why and how this happens has puzzled scientists for a long time. Now, scientists have uncovered a major clue as to why. Parts of the brain originally thought to only process vision are also organized according to a "map" of the body, allowing what we see to trigger echoes of touch sensations. 

The study, published recently (Wednesday, 26 November), in the journal Nature, shows that watching movies can activate touch-processing regions of your own brain in a highly organized way. In short, your brain doesn't just watch, it simulates what it sees. 

When you watch someone being tickled or getting hurt, areas of the brain that process touch light up in patterns that match the body part involved. Your brain maps what you see onto your own body, 'simulating' a touch sensation even though nothing physical happened to you.

This cross-talk works in the other direction too. For example, when you navigate to the bathroom in the dark, touch sensations help your visual system create an internal map of where things are, even with minimal visual input. This 'filling in' reflects our different senses cooperating to generate a coherent picture of the world.

Nicholas Hedger, Vicarious body maps bridge vision and touch in the human brain, Nature (2025). DOI: 10.1038/s41586-025-09796-0. www.nature.com/articles/s41586-025-09796-0

Part1

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:19am

To confirm feathers were the cause, the scientists also studied two related pheasant species that lack elaborate head plumage. In these birds, male and female fields of vision were identical. 

According to the researchers, the enlarged blind area of the Lady Amherst's and golden pheasant males leaves them more vulnerable to predation than females. This visual cost is the latest example of the handicap principle, an evolutionary idea that suggests that if a male can survive despite carrying a feature that puts it at a disadvantage, it must have superior genes.

"The reduced visual field in males compared to females in these pheasants, as a result of feather ornamentation, could be viewed as a relative handicap," wrote the researchers in their paper.

Alexandra E. R. Lamond et al, The visual impediment of cranial ornamentation in male Chrysolophuspheasants, Biology Letters (2025). DOI: 10.1098/rsbl.2025.0405

Part2

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:18am

Flashy feathers may put some male pheasant species' lives at risk

The male Lady Amherst's pheasant knows how to put on a show when it comes to attracting mates. As well as elaborate courtship displays, they will unfurl their golden feathers to form a cape around their neck, which can prove irresistible to some females of the species. 

However, according to new research published in the journal Biology Letters, this spectacular ornamentation comes at a potentially life-threatening cost. It can severely restrict their field of vision, making them more vulnerable to predators.

As with most animals, vision is critical for birds, helping them forage for food, spot lurking predators, and keep an eye on rivals. For years, scientists understood that a bird's vision was largely shaped by its ecology (where it lives, what it eats, and how it forages) rather than its gender. But this research is the first to show that male and female birds see the world differently.

The study authors used a technique called ophthalmoscopic reflex to map the bird's visual field. This involves shining a light into a bird's eye and mapping where the reflection disappears, which marks the edge of its field of vision.

The team studied four captive Lady Amherst's pheasants and three golden pheasants (males of this species also have a colorful cape of feathers).

They found that males have a 30 to 40-degree smaller vertical range of binocular vision, which means they can't see as well above and in front of their heads. The researchers also discovered that males have a blind spot that is much larger than females, measuring over 114 square centimeters compared to about 21 square centimeters. The blind spot behind their head was also wider than that of females by about 10 degrees.

Part1

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:18am

Persistent environmental toxins already accumulate in animal tissues during the fetal stage, research finds

Persistent organic pollutants (POPs) begin to accumulate in the tissues of mammals already during the fetal stage, according to new research.

  The animal-model study found that environmental toxins had built up in the tissues of sheep raised in clean organic production, and that the same substances were transferred in notable amounts to the developing fetuses' adipose tissue. 

Persistent environmental toxins, such as PCBs and DDT, remain in nature for long periods without breaking down. They can accumulate in the fatty tissues of organisms and bioaccumulate through the food chain. These substances were previously used in industry and as insecticides, and although their use is now strictly regulated, they remain widespread in the environment.

A study appearing in Environmental Research analyzed tissue samples from 15 organic ewes and their lambs shortly after birth, searching for the most common POPs.

Almost all of the substances investigated were detected in both adult sheep and lamb tissues. All the compounds identified were able to cross the placenta, and the transfer was so effective that concentrations in the lambs' tissues averaged 30–103% of those measured in the mothers. 

Because placental structure in sheep differs from that in humans, no direct conclusions can be drawn regarding human exposure. However, concentrations of POPs in adult human adipose tissue are on average higher than in sheep, underscoring the need for further research. 

In epidemiological studies, POP concentrations measured from umbilical cord blood after birth have been linked to obesity, metabolic syndrome and lower IQ 

Ella Vuoti et al, Adipose tissue deposition and placental transfer of persistent organic pollutants in ewes, Environmental Research (2025). DOI: 10.1016/j.envres.2025.123164

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:18am

Mini-fridges on a nanoscale? New cooling technique could make computer chips more powerful

A new ion-based cooling method uses voltage-controlled nanopores in semiconductor membranes to drive selective ion flow, enabling localized heating or cooling at the nanoscale. This approach achieves temperature drops over 2 K and is compatible with current chip fabrication, offering improved thermal management and reduced environmental impact for advanced semiconductor devices.

Makusu Tsutsui et al, Gate-Tunable Ionothermoelectric Cooling in a Solid-State Nanopore, ACS Nano (2025). DOI: 10.1021/acsnano.5c13339

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:15am

Schizophrenia-spectrum disorders may originate in specific brain regions that show early structural damage

 

Schizophrenia-spectrum disorders are linked to early structural damage in specific brain regions, particularly the temporal, cingulate, and insular lobes, with reduced morphological similarity indicating network disconnection. These changes are more pronounced in severe cases and correlate with altered neurobiology, including increased astrocytes, neurotransmitters, and reduced metabolism.

Natalia García-San-Martín et al, Reduced brain structural similarity is associated with maturation, neurobiological features, and clinical status in schizophrenia, Nature Communications (2025). DOI: 10.1038/s41467-025-63792-6

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:13am

Interestingly, Ash1l belongs to a family of proteins called histone methyltransferases that retain memory in other biological systems as well. "In the immune system, these molecules help the body remember past infections; during development, those same molecules help cells remember that they've become a neuron or muscle and maintain that identity long-term. The brain may be repurposing these ubiquitous forms of cellular memory to support cognitive memories.

The findings may have implications for memory-related diseases.

By identifying the gene programs that preserve memory, researchers may eventually find ways to route memory through alternate circuits and around damaged parts of the brain in conditions such as Alzheimer's.

If we know the second and third areas that are important for memory consolidation, and we have neurons dying in the first area, perhaps we can bypass the damaged region and let healthy parts of the brain take over.

Part3

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:12am

For decades, memory research focused on two brain regions: the hippocampus, home of short-term memory, and the cortex, which was thought to house long-term memories. The latter, scientists imagined, lie gated behind biological on-and-off switches.

Existing models of memory in the brain involved transistor-like memory molecules that act as on/off switches

In other words, in this model, if a short-term memory was tagged for long-term storage, it would remain so indefinitely. But, even as investigations in this vein led to numerous insights, researchers understood that this model was ultimately too simple—for instance, it didn't account for why some long-term memories last weeks while others last a lifetime.

Then, in 2023, the same researchers published a paper that identified a brain pathway that links short- and long-term memories. An important component of which is a region in the center of the brain called the thalamus, which not only helps select which memories should be remembered, but routes them to the cortex for long-term stabilization.

The findings set the stage for tackling some of the most fundamental questions in the field of memory research: What happens to memories beyond short-term storage in the hippocampus—and what molecular mechanisms are behind the sorting process that promotes important memories to the cortex and demotes unimportant ones to be forgotten?

To answer these questions, the team developed a behavioral model using a virtual reality system where mice formed specific memories.

The results suggest that long-term memory is not maintained by a single molecular on/off switch, but by a cascade of gene-regulating programs that unfold over time and across brain regions like a series of molecular timers.

Initial timers turn on quickly and fade just as fast, allowing for rapid forgetting; later timers act more slowly but create more durable memories. This stepwise process allows the brain to promote important experiences for long-term storage, while others fade.

In this study, the researchers used repetition as a proxy for importance, comparing memories of frequently repeated contexts to those encountered less often. The team identified three transcriptional regulators: Camta1 and Tcf4 in the thalamus, and Ash1l in the anterior cingulate cortex, which are not necessary for initially forming memories, but are crucial for maintaining them. Disrupting Camta1 and Tcf4 impaired functional connections between the thalamus and cortex, leading to memory loss.

The model suggests that, after the basic memory is formed in the hippocampus, Camta1 and its targets ensure the initial persistence of the memory. With time, Tc4 and its targets are activated, providing cell adhesion and structural support to further maintain the memory. Finally, Ash1l recruits chromatin remodeling programs that make the memory more persistent.

Unless you promote memories onto these timers, the researchers think you're primed to forget it quickly.

Part2

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:12am

How the brain decides what to remember: Study reveals sequentially operating molecular 'timers'

Every day, our brains transform quick impressions, flashes of inspiration, and painful moments into enduring memories that underpin our sense of self and inform how we navigate the world. But how does the brain decide which bits of information are worth keeping—and how long to hold on?

Now, new research demonstrates that long-term memory is formed by a cascade of molecular "timers" unfolding across brain regions. With a virtual reality-based behavioral model in mice, the scientists discovered that long-term memory is orchestrated by key regulators that either promote memories into progressively more lasting forms or demote them until they are forgotten. 

The findings, published in Nature, highlight the roles of multiple brain regions in gradually reorganizing memories into more enduring forms, with gates along the way to assess salience and promote durability.

This is a key revelation because it explains how we adjust the durability of memories.  What we choose to remember is a continuously evolving process rather than a one-time flipping of a switch.

Initial timers turn on quickly and fade just as fast, allowing for rapid forgetting; later timers act more slowly but create more durable memories. This stepwise process allows the brain to promote important experiences for long-term storage, while others fade. 

Unless you promote memories onto these timers, the researchers think you're primed to forget it quickly.

Priya Rajasethupathy, Thalamocortical transcriptional gates coordinate memory stabilization, Nature (2025). DOI: 10.1038/s41586-025-09774-6. www.nature.com/articles/s41586-025-09774-6

Part1

Comment by Dr. Krishna Kumari Challa on December 1, 2025 at 8:11am

High levels of forever chemicals found in dolphins and whales

New research has revealed that marine mammals who live far below the ocean's surface are not immune from the burden of toxic forever chemicals, with whales and dolphins showing unprecedented levels of PFAS contamination. 

The findings challenge the assumption that a deep-sea habitat offers protection from human-made per- and polyfluoroalkyl substances, otherwise known as PFAS. 

Published in Science of the Total Environment, the findings raise concerns about the long-term health of marine species and the invisible legacy that forever chemicals are leaving in the environment. PFAS are human-made chemicals that accumulate through the food chain and can disrupt immune, endocrine and reproductive systems, raising concerns for both individual and population health in humans and animals, including cetaceans. 

The scientists analyzed tissues from 127 animals across 16 species of toothed whales and dolphins .

The researchers looked at how the acquisition of forever chemicals varied according to species, sex, age and the habitat in which they predominantly live and feed. 

The results showed that  even offshore and deep-diving species are exposed to similar levels of PFAS, highlighting how widespread pollution, compounded by climate-driven stressors, poses a growing threat to marine biodiversity.

Karen A. Stockin et al, No place to hide: Marine habitat does not determine per- and polyfluoroalkyl substances (PFAS) in odontocetes, Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2025.180701

• ‹ Previous
• 1
• …
• 9
• 10
• 11
• 12
• 13
• …
• 1162
• Next ›
• Page