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Comment by Dr. Krishna Kumari Challa 12 hours ago

'Momnesia' is real—scientists find a biological explanation for temporary forgetfulness during pregnancy

Many women say the same thing during pregnancy: They walk into a room and forget why, misplace their keys or struggle to follow a conversation. This phenomenon, often called "pregnancy brain" or "momnesia," has long lacked a clear biological explanation.
Now, a new study by researchers at Baylor College of Medicine and collaborating institutions, published in Science Bulletin, identifies a specific brain circuit in an animal model that becomes disrupted under the sustained high estrogen levels present during pregnancy. The findings offer the first biological explanation of how exposure to high levels of circulating estrogen can temporarily impair memory.
The new findings suggest a possible explanation—it may not simply be a matter of "more estrogen is better" or "worse," but rather where in the brain estrogen acts and at what levels.

"Low-level, cyclical estrogen exposure appears to support cognitive function, which is part of why hormone therapy can help postmenopausal women.
But sustained, high-level estrogen exposure seems to engage a different pathway altogether, one centered in the hypothalamus rather than the hippocampus itself. That distinction may help reconcile a lot of conflicting data in the field.
Sustained high estrogen impaired task-specific memory in mice by reducing estrogen receptor-α signaling in lateral hypothalamic GABAergic neurons, increasing activity in a hypothalamus–hippocampus circuit. Silencing this pathway prevented impairment. In pregnant women, late-pregnancy memory deficits correlated with estrogen levels and appeared temporary.
To determine whether these findings translate to humans, the researchers assessed memory performance in women across different stages of pregnancy. They found task-specific memory impairments that emerged during late pregnancy and correlated with circulating estrogen levels, even after accounting for other factors that might influence cognition. These human data support the idea that the hormone-driven circuit identified in mice may underlie the memory changes many pregnant women experience.
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Momnesia is real, it has a defined biological basis and is temporary. The memory changes observed in both mice and women were temporary and task-specific, not a sign of broader cognitive decline.

Xin Li et al, High-level estrogen impairs memory via estrogen receptor signaling in a hypothalamic–hippocampal neural circuit, Science Bulletin (2026). DOI: 10.1016/j.scib.2026.08.057

Comment by Dr. Krishna Kumari Challa 12 hours ago

To work around these impediments, the team engineered a nonpathogenic E. coli bacterium to carry a phage that only infects Salmonella. This ensures that when the phage is produced, it can specifically target the pathogen.

Usually, this type of Salmonella phage remains dormant in the Salmonella bacterial genome, but researchers of this study made several genetic modifications so that it is carried by E. coli, and, once it is released into the gut, it automatically kills Salmonella in a process called lysis. This process rapidly increases the number of phages to fight the bacteria. The researchers coined this new type of phage-bacterial combination a "lytic phage-producing lysogen," or "lyto-lysogen."
Salmonella can typically detect phage DNA produced by non-Salmonella bacteria and prevent it from replicating. But in this case, the researchers were able to disguise the phage.
They were able to trick the Salmonella bacteria into thinking the phage from E. coli was 'not foreign' by adding a Salmonella gene into the E. coli genome.
A phage that comes from their E. coli can infect Salmonella, can propagate easily in Salmonella, lyse it, and then all the phages that are produced from Salmonella can just keep replicating."

This rapid reproduction eventually leads to the eradication of the infection from the gut.
What happens is that this good bacterium, the E. coli, produces all this antipathogen phage, and there is now a protective lining so that when Salmonella comes in, just after passing through the stomach and at its weakest point, it meets this high, killer density of phages.
The researchers say they targeted Salmonella due to its high global disease burden, as it can kill the elderly, children and those with HIV; it has a high prevalence of antibiotic resistance; and it has been upgraded to a high-priority pathogen.

Nature Microbiology (2026). DOI: 10.1038/s41564-026-02484-3

Part 2

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Comment by Dr. Krishna Kumari Challa 12 hours ago

First-of-its-kind preventive phage therapy provides promising results against Salmonella
The mammalian gut microbiome teems with a delicate balance of bacteria and the viruses that keep them in check, called bacteriophages, or phages. Each bacterial species usually has its own set of phage partners.
When bad bacteria enter this ecosystem, there are typically no phages present, allowing them to cause mayhem. By the time the host is sick, it is too late for phages; they'll simply reach a balance with the bad bacteria.

But what if the phages in the gut could prepare for the orally ingested pathogen and strike it down as it enters the gut, negating the need for a battle?
Researchers recently demonstrated that this prophylactic approach, using an engineered, nonpathogenic E. coli bacterium, successfully protected mice from an oral Salmonella infection.

Engineered nonpathogenic E. coli produced a modified Salmonella-specific lytic phage in the gut, creating high local phage densities before pathogen exposure. Prophylactic administration protected mice from oral Salmonella infection by enabling phage amplification and bacterial lysis.

Bacteriophages, or phages, are viruses of bacteria and do not infect humans or animals. Phage therapy, the use of phages to treat bacterial infections, is particularly hard to make successful for treating intestinal pathogens.

It's challenging, especially in the gut, because phages and bacteria tend to coexist for long periods of time.

This coexistence makes establishing the high phage-to-bacteria ratio needed to treat intestinal infections hard to achieve.

That's extremely challenging to achieve in your gut.
And then once you have a bacterial infection in your gut, a lot of times it's just not even accessible to phages. It's already hidden away in the mucosa or cells of your body; it's not just free-flowing to where the phages would be able to access the bacteria.
Part 1

Comment by Dr. Krishna Kumari Challa 12 hours ago

Stable frontal signals, flexible hippocampal ones: How the brain preserves context as goals change

While humans are completing a task, they can temporarily store information in their minds while also manipulating and adapting it based on changing circumstances. To support this capability, known as working memory, the brain needs to hold onto important context about a task, updating it when rules, goals or circumstances change.
Researchers recently carried out a study aimed at better understanding how neurons preserve context over time as the goals of an ongoing task change. Their findings, published in Nature Human Behaviour, suggest that the brain can represent the same information through different patterns of neuronal activity that vary in stability and flexibility.
Researchers were inspired by the remarkable ability of an individual to relentlessly pursue a goal over long periods of time, while still remaining flexible and encoding information about a changing environment. No other animal can encounter an arbitrary set of rules or behavioural constraints, immediately internalize them, and adhere to them without continuous reminders or a massive amount of conditioning or reinforcement. So the researchers wanted to study how different structures in the brain perform computations in support of these uniquely human behaviours.
This study offers valuable new insights into how the human brain represents context as people complete tasks. Specifically, it suggests that neurons in the medial frontal cortex can maintain a stable pattern of activity to represent a rule for several minutes, even when reminders of this rule are no longer present.

This mechanism could explain how we are able to continually remember what behaviour to engage in long after the associated instructions or cues for that behaviour are gone.
They also demonstrated that the hippocampus forms a uniquely flexible rule representation whose format changes over time depending on what kind of behaviour the person needs to exhibit. These findings are notable because they draw attention to the utility of rule representations that are stable across time and across incoming stimuli, which is thought to enable the human ability to rapidly generalize behaviour to new contexts.

Hristos S. Courellis et al, Neural dynamics underlying minute-timescale persistent behaviour in the human brain, Nature Human Behaviour (2026). DOI: 10.1038/s41562-026-02537-x.

Comment by Dr. Krishna Kumari Challa yesterday

How myth-busting science changed cerebral palsy
Most cerebral palsy cases arise from factors during pregnancy or early infancy rather than birth trauma or oxygen deprivation. Genetic analyses identified an underlying cause in at least one quarter of affected individuals, often present from conception. These findings have informed diagnostic practice and reduced unsupported obstetric litigation.
This also reduced cesarean  births.

Alistair Maclennan, How cerebral palsy litigation based on myth and non-expert opinion adversely affected obstetric practice worldwide, South Australian Journal of Medicine (2026). DOI: 10.66861/ofzz1318

Comment by Dr. Krishna Kumari Challa yesterday

Planting trees in the wrong places is not a climate solution
Tree planting benefits climate mitigation only where it restores naturally forested ecosystems. Afforesting drylands, grasslands and savannas can reduce water availability, biodiversity and surface reflectivity, offsetting carbon gains. Restoration should prioritize ecosystem-specific measures such as natural regeneration, soil conservation and native vegetation protection.

 original article.

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Skipping showers is the latest trend. But is there any science to 'pheromone' maxxing?

Humans have no confirmed pheromones or functional sensory anatomy known to mediate pheromone responses. Fresh sweat is largely odorless; bacterial growth during infrequent washing produces body odor. Evidence that MHC-related body odor influences human attraction is inconsistent, with meta-analysis showing no overall effect.

original article.

Comment by Dr. Krishna Kumari Challa yesterday

A pathogen turns flowers into leaves

Scientists have found how a protein produced by bacteria disrupts the mechanism that controls flower development in plants, turning reproductive organs into leaf-like structures. These findings shed light on a plant disease that is expected to spread as climate change expands the range of its insect vectors in northern latitudes.
Phytoplasmas are bacteria that are transmitted to plants by insects. Symptoms of the pathogen can range from triggering dwarfism in the plant to essentially reprogramming plant development: Instead of flowers, all floral organs—sepals, petals, stamens and carpels—are converted to leaves, affecting diverse crops such as sunflowers, sesame and grapevines.

This effect can have economic consequences, as food might not be as readily available from damaged crops.

The phytoplasma protein PHYLOY binds multiple MADS-box transcription factor combinations through structural mimicry, disrupting complexes that specify floral organ identity. This interference converts sepals, petals, stamens, and carpels into leaf-like structures. Mutational analyses identified features enabling or preventing these interactions.

Antonin Galien et al, The phytoplasma effector, phyllogen, structurally mimics host plant MADS transcription factors, Journal of Biological Chemistry (2026). DOI: 10.1016/j.jbc.2026.113449

Comment by Dr. Krishna Kumari Challa yesterday

Chatty chatbots can mislead users, but verification tools help, researchers find

Researchers found in a recent study that the more conversational an AI chatbot is, the more likely users are to trust it—even when it shares misinformation. The team said verification options may help rebuild needed skepticism.

More conversational AI chatbots were judged more credible than less conversational versions, even when providing clearly false health information. In 477 participants, skepticism increased only when users actively used verification buttons; passive warning cues did not reduce trust.

Mengqi Liao et al, Chat but verify: Combating misinformation in conversational Generative AI with verification affordance, Journal of Computer-Mediated Communication (2026). DOI: 10.1093/jcmc/zmag012

Comment by Dr. Krishna Kumari Challa yesterday

Rust prevention coating uses nanotech to self-repair and conquer corrosion

A single application of a "smart" self-repairing coating is being developed to dramatically extend rust protection for buildings, bridges, cars and other steel components.
Nanomaterials experts have engineered powder-like particles that can turn water-based paint into self-repairing corrosion shields with the potential to slow rusting by more than 600 times compared with existing high-performance coatings.
The particles were effectively tiny containers that released rust-inhibiting molecules to protect damaged areas of the coating.

All rustproof coatings inevitably wear down over time; there is no stopping that.
What the researchers have now created is a barrier that is constantly sensing if something is wrong so it can patch any scrapes and cracks itself, greatly extending the duration of protection.
To create the coating, the researchers encased the common rust inhibitor benzotriazole in an intricate nanostructure that, when added to waterborne polyurethane coatings, creates a composite that is highly responsive to changes in acidity.

Each tiny particle is basically a nanocontainer that releases repair molecules only when the conditions demand it.
Electrochemical testing indicates this self-healing coating can restrict corrosion to 37 nanometers per year, 600 times more effectively than many existing "high-performance" rust-protection products that report an ability to restrict annual corrosion to 0.025 mm.

It is not a coating that will last forever, but coatings that contain this technology will have a greatly expanded lifetime, meaning far less maintenance and a much longer time between applications.

Asep Sugih Nugraha et al, Micelle‐Assisted Encapsulation Strategy in Metal‐Organic Framework Nanocontainers Enables Durable Corrosion Protection, Small Science (2026). DOI: 10.1002/smsc.70367

Comment by Dr. Krishna Kumari Challa yesterday

Scientists pinpoint two brain regions that battle it out when deciding whether to take a risk
Every day, your brain runs the same calculation: Take a risk or play it safe? Your gas tank might be low, but there's just enough to make it to work on time. Do you stop and risk being late? Talk to a stranger at the park or stay quiet?
Scientists have discovered the exact spot in the brain where decisions like these take shape—and they can see each result coming half a second before a person acts.

Their study, published in Nature Neuroscience, recorded brain activity directly from the orbitofrontal cortex, a region just behind the eyes. By working with patients who already had electrodes implanted there for surgical evaluation of epilepsy, the team found two neighbouring patches of the brain that signal in opposite directions: one pushing toward "do it," the other toward "don't."

The discovery could reshape how doctors treat psychiatric conditions characterized by an imbalance between risk-taking and caution, from depression and OCD to addiction and gambling disorders. Patients with OCD, which gives rise to intrusive thoughts and repetitive behaviors, and those with depression demonstrate excessive avoidance. This pattern may reflect an imbalance in this neural circuitry that is playing out in everyday decision-making.

Researchers found that a region near the middle of the eyebrow, called the medial orbital sulcus, increased its activity just before patients took a risk, such as going down a bomb-lined hallway. A patch about two centimeters (0.8 inches) over, toward the side of the eyebrow, did the opposite. Its activity spiked before patients avoided a risk, like skipping the bomb-lined hallway. The two signals moved in exact opposition to each other, down to the millisecond.

To understand how these two signals might produce a single decision, the researchers built a computer model of their interactions. Their model proposed that the circuit behaved like a tug-of-war: One side's signal would shoot up as the other dropped, and vice versa, with one side eventually winning out.

On easy decisions the "go for it" signal won almost instantly. On harder calls, with a more even mix of risk and reward, the two signals flickered back and forth several times before settling on a final answer. Using the pattern of brain activity alone, the researchers could tell which way a patient was about to decide before they moved.
What the researchers clearly saw was more like a switch flipping back and forth, oscillating between two extremes until one held.

Intracranial recordings in humans reveal differential contributions of medial and lateral orbitofrontal cortex to approach–avoidance decision-making, Nature Neuroscience (2026). DOI: 10.1038/s41593-026-02444-4

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