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Comment by Dr. Krishna Kumari Challa 7 hours ago

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 7 hours ago

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 9 hours ago

Comment by Dr. Krishna Kumari Challa 9 hours ago

How to STOP A Dog Attack BEFORE It Happens!

Comment by Dr. Krishna Kumari Challa 9 hours ago

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 10 hours ago

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

Comment by Dr. Krishna Kumari Challa 10 hours ago

The way we talk to chatbots affects their accuracy, new research reveals

Whether we're seeking customer support, looking for recommendations, or simply asking a quick question, AI chatbots are designed to give us the answers we're looking for. But there's more going on beneath the surface. Every time we chat with them, they are learning from us to improve their understanding and responses. And the type of language we use, whether formal or informal, directly affects the quality of their answers, according to new research.

In general, people naturally adapt their conversation style to the person they are speaking with. 

The researchers compared thousands of messages people sent to human agents with those sent to AI chatbots, focusing on features like grammar, vocabulary and politeness. They found that people were 14.5% more polite and formal and 5.3% more grammatically fluent when chatting with humans than when talking with AI, based on analysis by the Claude 3.5 Sonnet model.

Next, they trained an AI model called Mistral 7B on about 13,000 real chats between people, then tested how well it understood more than 1,300 messages people had sent to chatbots. To broaden the AI's exposure, they also created blunt and polite rewrites of those messages to simulate different communication styles.

It turns out that chatbots trained on a diverse mix of message styles, including real and fake messages, were 2.9% better at understanding user intent than AI trained solely on original human conversations. The researchers also tried to improve Mistral AI's understanding by rewriting informal messages at the last minute to be more formal, but this led to a drop in understanding by almost 2%.

So the best way to make chatbots smarter is to train them on a range of communication styles, as the researchers state in their paper published on the arXiv preprint server. "Training-time exposure to diverse linguistic variation is more effective than inference-time normalization. Models must learn to interpret diverse communication styles during training, rather than rely on brittle post-hoc transformations that risk semantic distortion."

Fulei Zhang et al, Mind the Gap: Linguistic Divergence and Adaptation Strategies in Human-LLM Assistant vs. Human-Human Interactions, arXiv (2025). DOI: 10.48550/arxiv.2510.02645

Comment by Dr. Krishna Kumari Challa 10 hours ago

Interestingly, when the team disrupted this pathway's activity, they found that mice no longer stopped drinking and developed hyponatremia. This is a condition characterized by overhydration and an abnormally low concentration of sodium in the blood.

This recent study gathered new valuable insight into how the mouse brain prevents overhydration, signaling that it is time to stop drinking.

Lingyu Xu et al, A bottom-up septal inhibitory circuit mediates anticipatory control of drinking, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02056-4.

Part 2

Comment by Dr. Krishna Kumari Challa 10 hours ago

Preventing overhydration: Study uncovers a neural circuit that prompts mice to stop drinking

Identifying the neural mechanisms that support the regulation of vital physiological processes, such as drinking, eating and sleeping, is a long-standing goal within the neuroscience research community. As the disruption of these processes can severely impact people's health and everyday functioning, uncovering their neural and biological underpinnings is of the utmost importance.

New insights gathered by neuroscientists could ultimately inform the development of more effective interventions designed to regulate vital physiological processes. Thirst and hunger are known to be regulated by homeostatic processes, biological processes that allow the body to maintain internal stability.

Yet drinking behaviour can also be anticipatory, which means that animals and humans often adjust their actions (i.e., stop drinking) before the concentration of substances in the blood changes in response to drinking water. The mechanisms through which the brain predicts when it is the right time to stop drinking remain poorly understood.

Researchers  recently carried out a study involving mice aimed at shedding new light on these mechanisms. Their findings, published in Nature Neuroscience, led to the identification of a neural pathway that reduces neural activity in specific regions of the mouse brain, signaling that the body has received enough water.

Drinking behaviour is not only homeostatically regulated but also rapidly adjusted before any changes in blood osmolality occur, known as anticipatory thirst satiation.

Homeostatic and anticipatory signals converge in the subfornical organ (SFO); however, the neural pathways conveying peripheral information to the SFO before changes in blood composition are incompletely understood till now.

Researchers now  reveal an inhibitory pathway from the medial septum (MS) to the SFO that is involved in the control of anticipatory drinking behaviour in mice.

As part of their experiments, researchers observed the drinking behavior of adult mice, while recording their neural activity. This led to the discovery of a neural pathway connecting the MS, a small region in the mouse brain that contributes to the synchronization of brain circuits, and the SFO, a region implicated in the monitoring of bodily fluids.

"MS γ-aminobutyric acid (GABA)ergic neurons encode water-satiation signals by integrating cues from the oral cavity and tracking gastrointestinal signals," wrote the authors in their research paper. "These neurons receive inputs from the parabrachial nucleus and relay to SFOCaMKII neurons, forming a bottom-up pathway with activity that prevents overhydration. Disruption of this circuit leads to excessive water intake and hyponatremia."

Essentially, the researchers found that after a mouse starts drinking, GABAergic neurons in the MS become active and receive signals from the parabrachial nucleus, a brain region that processes signals originating from the mouth and gut. These GABAergic neurons then send inhibitory signals to neurons in the SFO, which in turn modulate the feeling of thirst.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

'Jump-scare' science: Study elucidates how the brain responds to fear

In haunted houses across the US this month, threatening figures will jump out of the shadows, prompting visitors—wide-eyed and heart racing—to instinctively freeze and flee.

Evolutionarily speaking, this "innate threat response" is key to survival, helping a wide variety of animal species escape predators. But when stuck in overdrive it can cause problems for humans.

A  research team has identified a novel brain circuit responsible for orchestrating this threat response. Known as the interpeduncular nucleus (IPN), this dense cluster of specialized neurons not only jump-starts that freeze-and-flee reaction, but dials it down when animals learn there's no real danger.

In people with anxiety or post-traumatic stress disorder (PTSD), this circuit may be broken, researchers say.

The findings could help explain why some people have a greater appetite for risk than others and lead to new therapies for psychiatric disorders.

The brain's threat system is like an alarm. It needs to sound when danger is real, but it needs to shut off when it's not. This new study shows how the brain learns to fine-tune those responses through experience, helping us adapt to the world.

 Elora W. Williams et al, Interpeduncular GABAergic neuron function controls threat processing and innate defensive adaptive learning, Molecular Psychiatry (2025). DOI: 10.1038/s41380-025-03131-9

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