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Comment by Dr. Krishna Kumari Challa 5 hours ago

Scientists Just Discovered a Whole New Type of Connection Between Neurons

Super-resolution microscopes have revealed a whole new type of connection between neurons in mouse and human brains.

In the lab,  researchers identified tiny tubular bridges in the branching tips of cultured neurons. In further tests on mouse models of Alzheimer's disease, it appeared the bridges were shuttling calcium and disease-related molecules directly between cells.

Similar] structures can transport a vast range of materials, from small ions (10⁻¹⁰m) to large mitochondria (10⁻⁶ m)," the team writes in their paper.

In cultured neurons, we observed these nanotubes forming dynamically and confirmed that they possessed a distinct internal structure, setting them apart from other neuronal extensions.

Neurons are well known for passing rapid messages to each other using synapses to transmit both electrical and chemical information. Yet, other cell types are known to use physically connecting bridging tubes to exchange molecules. Researchers have just confirmed that a similar type of tube bridge occurs in neurons too, using advanced imaging and machine learning.

The researchers observed the nanotubes transporting amyloid-beta molecules that they had injected into mouse brain cells. These molecules have been implicated in neurodegenerative diseases like Alzheimer's, where they tend to clump together abnormally. When researchers stopped the bridges from forming, the amyloid-beta stopped spreading between cells, too, confirming that the nanotubes acted as direct conduits.

The computational model supported these findings, predicting that overactivation in the nanotube network could accelerate the toxic accumulation of amyloid in specific neurons, thereby providing a mechanistic link between nanotube alterations and the progression of Alzheimer's pathology," the researchers explain. 

https://www.science.org/doi/10.1126/science.adr7403

Comment by Dr. Krishna Kumari Challa 5 hours ago

Bats' brains reveal a global neural compass that doesn't depend on the moon and stars

Some 40 kilometers east of the Tanzanian coast in East Africa lies Latham Island, a rocky, utterly isolated and uninhabited piece of land about the size of seven soccer fields. It was on this unlikely patch of ground that  researchers recorded—for the first time ever—the neural activity of mammals in the wild.

In their study, published in Science, the team used a tiny device to record, at the level of single neurons, the brain activity of fruit bats as they flew around the island. The scientists discovered that the bats' neuronal "compass" is global: It provides stable directional information across the entire island and does not depend on the moon or stars.

Many species share the behavioral ability to orient themselves using an "internal compass," and it is quite possible that humans rely on the same neural mechanism that was studied in these bats.

They found that every time the bats flew with their heads pointing in a particular direction—north, for instance—a unique group of neurons became active, creating an "internal compass." Navigation by means of directional neurons had previously been observed in the lab, but this was the first evidence that it happens in nature as well. When the researchers analyzed the recordings from different parts of the island, they discovered that the activity of the head-direction cells was consistent and reliable across the entire island, enabling the bats to orient themselves over a large geographical area.

 The compass is global and uniform: No matter where the bat is on the island and no matter what it sees, specific cells always point in the same direction—north stays north and south stays south. 

 Shaked Palgi et al, Head-direction cells as a neural compass in bats navigating outdoors on a remote oceanic island, Science (2025). DOI: 10.1126/science.adw6202. www.science.org/doi/10.1126/science.adw6202

Comment by Dr. Krishna Kumari Challa 5 hours ago

Comprehending the expansion of the universe without using 'Dark Energy'

Why is the universe expanding at an ever-increasing rate? This is one of the most exciting yet unresolved questions in modern physics. Because it cannot be fully answered using our current physical worldview, researchers assume the existence of a mysterious "dark energy." However, its origin remains unclear to this day.

An international research team has come to the conclusion that the expansion of the universe can be explained—at least in part—without dark energy.

In physics, the evolution of the universe has so far been described by the general theory of relativity and the so-called Friedmann equations. However, in order to explain the observed expansion of the universe on this basis, an additional "dark energy term" must be manually added to the equations.

This unsatisfactory solution prompted the researchers to take a different approach. Their findings, published in the Journal of Cosmology and Astroparticle Physics, are based on an extension of general relativity (GR) by the later developed model of Finsler gravity. Unlike the original explanatory approach of GRT, the Finsler model allows for a more accurate modeling of the gravitational force of gases, as it is based on a more general spacetime geometry than GRT.

When the research team calculated the Finsler extension of the Friedmann equations, they made an exciting discovery: The Finsler-Friedmann equations already predict an accelerated expansion of the universe in a vacuum—without the need to introduce additional assumptions or "dark energy" terms.

We may now be able to explain the accelerated expansion of the universe without dark energy, based on a generalized spacetime geometry, say the researchers. The new geometry opens up completely new possibilities for better understanding the laws of nature in the cosmos.

Christian Pfeifer et al, From kinetic gases to an exponentially expanding universe—the Finsler-Friedmann equation, Journal of Cosmology and Astroparticle Physics (2025). DOI: 10.1088/1475-7516/2025/10/050. On arXiv (2025). DOI: 10.48550/arxiv.2504.08062

Comment by Dr. Krishna Kumari Challa on Saturday

'Wetware': Scientists use human mini-brains to power computers

Wetware (brain), a term drawn from the computer-related idea of hardware or software, but applied to biological life forms.

'Wetware': Scientists use human mini-brains to power computers

Ten universities around the world are conducting experiments using FinalSpark's organoids -- the small company's website even has a live feed of the neurons at work.

Inside a lab in the picturesque Swiss town of Vevey, a scientist gives tiny clumps of human brain cells the nutrient-rich fluid they need to stay alive.

It is vital these mini-brains remain healthy, because they are serving as rudimentary computer processors—and, unlike your laptop, once they die, they cannot be rebooted.

This new field of research, called biocomputing or "wetware," aims to harness the evolutionarily honed yet still mysterious computing power of the human brain.

The scientists think that that processors using brain cells will one day replace the chips powering the artificial intelligence boom.

The supercomputers behind AI tools like ChatGPT currently use silicon semiconductors to simulate the neurons and networks of the human brain. Instead of trying to mimic, these scientists are using the real thing.

Among other potential advantages, biocomputing could help address the skyrocketing energy demands of AI, which have already threatened climate emissions targets and led some tech giants to resort to nuclear power.

Biological neurons are one million times more energy efficient than artificial neurons, these scientists say. They can also be endlessly reproduced in the lab, unlike the massively in-demand AI chips made by companies like behemoth Nvidia.

But for now, wetware's computing power is a very long way from competing with the hardware that runs the world.

Source: News agencies

https://www.newindianexpress.com/lifestyle/tech/2025/Oct/17/wetware...'Wetware'%3A%20Scientists%20use%20human%20mini%2Dbrains%20to%20power%20computers

Comment by Dr. Krishna Kumari Challa on Friday

What happens when the cell's 'antenna' malfunctions?

Researchers have uncovered the molecular mechanisms responsible for regulating a structure that plays a critical role in how cells communicate with their environment. Their new study has been published in Communications Biology.

Found on the surface of almost every cell, the primary cilium is a tiny antenna-like projection that enables the cell to sense environmental signals. Through this structure, cells regulate essential processes such as growth, development, and adaptation. For healthy functioning, primary cilia must maintain the correct length, stability, and morphology.

The research highlights the role of DYRK kinases, a family of enzymes that regulate intracellular processes. The findings  show that these kinases are essential for maintaining the length, stability, and shape of primary cilia.

When DYRK kinases malfunction, cilia may become abnormally long, structurally deformed, or unstable. In such cases, the cell loses its ability to properly sense and process external signals.

This discovery not only advances our understanding of fundamental cell biology but also provides new perspectives on health conditions linked to ciliary dysfunction, such as developmental disorders, kidney diseases, and vision loss. Moreover, it may open new avenues for addressing complex diseases in the future by uncovering potential targets for therapeutic intervention.

 Melis D. Arslanhan et al, Kinase activity of DYRK family members is required for regulating primary cilium length, stability and morphology, Communications Biology (2025). DOI: 10.1038/s42003-025-08373-5

Comment by Dr. Krishna Kumari Challa on Friday

Older fathers linked to more new gene mutations in puppies, study finds

An international study has shown how and when entirely new gene mutations, known as de novo mutations, originate in dogs. A key finding is that higher paternal age increases the number of de novo mutations in puppies. Maternal age also has an effect.

The study analyzed 390 parent–offspring trios. Trio denotes a design where the genomes of the puppy and both parents are sequenced. This enables accurately identifying gene mutations that do not occur in either parent's genome—mutations that have taken place in the sperm, the ovum or soon after conception. While these rare mutations are the basis of evolution, they can also predispose their carriers to hereditary diseases.

The results, published in Genome Biology, also show why dogs differ from humans in certain genomic regions and what the findings mean for canine health and breeding.

Shao-Jie Zhang et al, Determinants of de novo mutations in extended pedigrees of 43 dog breeds, Genome Biology (2025). DOI: 10.1186/s13059-025-03804-2

Comment by Dr. Krishna Kumari Challa on Friday

Comment by Dr. Krishna Kumari Challa on Friday

How to STOP A Dog Attack BEFORE It Happens!

Comment by Dr. Krishna Kumari Challa on Friday

Disconnected cerebral hemisphere in epilepsy patients shows sleep-like state during wakefulness

Sleep-like slow-wave patterns persist for years in surgically disconnected neural tissue of awake epilepsy patients, according to a study published in PLOS Biology.

The presence of slow waves in the isolated hemisphere impairs consciousness; however, whether they serve any functional or plastic role remains unclear.

Hemispherotomy is a surgical procedure used to treat severe cases of epilepsy in children. The goal of this procedure is to achieve maximal disconnection of the diseased neural tissue, potentially encompassing an entire hemisphere, from the rest of the brain to prevent the spread of seizures.

The disconnected cortex—the outer layer of neural tissue in the brain—is not surgically removed and has a preserved vascular supply. Because it is isolated from sensory and motor pathways, it cannot be evaluated behaviorally, leaving open the question of whether it retains internal states consistent with some form of awareness. More broadly, the activity patterns that large portions of the disconnected cortex can sustain in awake humans remain poorly understood.

Researchers recently tried to investigate these things.

They  used electroencephalography (EEG) to measure activity in the isolated cortex during wakefulness before and up to three years after surgery in 10 pediatric patients, focusing on non-epileptic background activity. Following surgery, prominent slow waves appeared over the disconnected cortex. This is novel evidence that this pattern can last for months and years after complete cortical disconnection. The persistence of slow waves raises the question of whether they play any functional role or merely reflect a regression to a default mode of cortical activity.

The pronounced broad-band EEG slowing resembled patterns observed in conditions such as deep non-rapid eye movement (NREM) sleep, general anesthesia, and the vegetative state. The findings indicate absent or reduced likelihood of dream-like experiences in the isolated cortex. Overall, the EEG evidence is compatible with a state of absent or reduced awareness.

According to the researchers, any inference about the presence or absence of consciousness, based solely on the brain's physical properties such as prominent EEG slow waves, should be approached with caution, particularly in neural structures that are not behaviorally accessible. The slowing observed at the scalp level should be further characterized with intracranial recordings in cases in which clinical outcomes require postoperative invasive monitoring.

Michele A. Colombo et al, Hemispherotomy leads to persistent sleep-likslow waves in the isolated cortex of awake humans, PLOS Biology (2025). DOI: 10.1371/journal.pbio.3003060

Comment by Dr. Krishna Kumari Challa on Friday

Men experience more brain atrophy with age despite women's higher Alzheimer's risk

Many women complained to me that their husbands "behaved strangely" as they got older and older. 

It seems they complained more, got irritated and angry more, understood situations less, grumbled a lot, ... and the descriptions take a strange turn as they go on describing them.

Now we have an explanation for such behaviours.

Women are far more likely than men to end up with Alzheimer's disease (AD). This may, at least partially, be due to women's longer average lifespans, but many scientists think there is probably more to the story. It would be easy to surmise that the increased risk is also related to differences in the way men's and women's brains change as they age. 

Now, a new study, published in Proceedings of the National Academy of Sciences, indicates that it's men who experience greater decline in more regions of the brian as they age. Researchers involved in the study analyzed 12,638 brain MRIs from 4,726 cognitively healthy participants (at least two scans per person) from the ages of 17–95 to find how age-related changes occurred and whether they differed between men and women.

The results showed that men experienced declines in cortical thickness and surface area in many regions of the brain and a decline in subcortical structures in older age. Meanwhile, women showed greater decline only in a few regions and more ventricular expansion in older adults. So, while differences in brain aging between the sexes are apparent, the cause of increased AD prevalence in women is still a bit mysterious.

These findings suggest that the higher prevalence of AD diagnoses in women likely stems from factors beyond differential rates of age-related brain atrophy," the study authors write.

One factor that might be to blame is genetics, particularly the APOE ε4 allele, which may affect protein accumulation in the brain and work differently in men and women. Other factors might include differences in hormonal changes, diagnosis patterns, and sociocultural influences.

Survival bias may also skew the results in AD studies, as more men may have been diagnosed with AD if their average lifespans matched women's more closely. In this particular study, participants were also more educated on average, which is a protective factor for AD—leading to a potential representativity bias.

When the researchers corrected for life expectancy, they say some of the differences did clear up for men and additional differences cropped up in women.

"The interpretation of these sex differences is complicated by our life expectancy analyses, which removed several cortical decline effects in men while revealing effects in women, including greater hippocampal decline. Whether this reflects the removal of proximity-to-death artifacts or elimination of biological aging differences cannot be determined, and these findings should be interpreted with caution, especially considering representativity bias in our sample with potentially healthier men," the authors explain.

Anne Ravndal et al, Sex differences in healthy brain aging are unlikely to explain higher Alzheimer's disease prevalence in women, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2510486122

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