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Comment by Dr. Krishna Kumari Challa on May 27, 2026 at 8:30am

How did we learn which plants are safe to eat? Food scientists explain
Humans identified edible and toxic plants through generations of observation, experimentation, and cultural knowledge, later enhanced by scientific analysis. Many plants contain natural toxins, but preparation methods such as soaking, cooking, and fermentation can reduce or eliminate harmful compounds. Modern science has further improved safety by breeding plant varieties with lower toxin levels. Toxicity often depends on dose and preparation, not just the presence of specific compounds.
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Memory decline after menopause linked to loss of estrogen production in brain tissue
Loss of brain-derived estrogen in aging female mice disrupts the extracellular matrix (ECM) in the hippocampus, impairing memory and social function, while males are unaffected. These findings suggest that postmenopausal estrogen decline uniquely increases Alzheimer's disease risk in women by altering ECM biology, highlighting a potential therapeutic target beyond amyloid-focused treatments.

Loss of brain-derived estrogen is associated with sex- and age-dependent alterations in memory, affective behavior, and hippocampal extracellular matrix gene expression, Aging Cell (2026).

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 11:01am

The first signs of human cremation may date back 100,000 years
Burned Homo sapiens bones from Ethiopia’s Afar Rift, dated to about 100,000 years ago, may represent the earliest evidence of human cremation. Undisturbed artifacts and fossils, including obsidian from distant sources, indicate complex behaviour, repeated short-term occupation, and long-distance movement. Local hydrological factors, rather than global climate, primarily shaped human adaptation in this region.
Significant fossils were found in the area, including remains of Homo sapiens individuals, among them bones that had been burned at high temperatures. This may indicate cremation and could represent the earliest known evidence of human cremation.

The remains also showed bite marks from predators and signs of sudden burial.

The study further shows that local hydrological factors—such as the flood cycles of the ancient Awash River—influenced human life more than global climate fluctuations.

Thousands of stone tools indicate that people repeatedly returned to the area for short periods on a seasonally flooding plain.

Artifacts documented at the site have remained in nearly undisturbed layers, giving researchers an unusually precise understanding of the spatial relationships between objects and fossils across a wide area.

This research helps us build a comprehensive understanding of how early Homo sapiens interacted with their environment.

Yonas Beyene et al, Halibee member archaeology: Middle Stone Age environment, technology, and postmortem modifications, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2534441123

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 9:45am

Freud's century-old ideas are colliding with modern brain science in ways that could change how minds are treated
Freud’s psychoanalytic concepts and the modern predictive brain model both describe the mind as oriented toward stability and predictability, with parallels between projection and prediction processes. Both frameworks explain persistent mental disorders as rigid, maladaptive prediction models that reduce uncertainty but distort reality. Integrating these perspectives may enhance understanding and treatment of mental disorders by linking neurological mechanisms with subjective experience.

Erik Stänicke et al, Freud's Model of the Mind Within a Predictive Processing Neuroscientific Paradigm, Entropy (2026). DOI: 10.3390/e28030318

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 9:37am

Blood pressure swings over 24 hours tied to poorer brain health

Frequent changes in blood pressure could affect cognitive health and contribute to brain changes associated with dementia risk, according to new research

Greater variability in blood pressure over 24 hours is associated with poorer cognitive performance and increased evidence of vascular brain injury. These fluctuations, even when modest, correlate with cognitive deficits equivalent to several years of aging, suggesting that dynamic blood pressure changes may contribute to dementia risk beyond average blood pressure levels.
Higher average blood pressure over 24 hours was also associated with greater evidence of vascular brain injury.
Even a modest increase in blood pressure variability was linked to lower performance on cognitive tests, equivalent to roughly seven years of additional aging.

Most people think of blood pressure as a single number taken in a doctor's clinic, but blood pressure is dynamic.

"Blood pressure rises and falls across the day and night, and those fluctuations may carry important information about brain health."

Madeline Gibson et al, Association of 24-Hour Blood Pressure Variability With Cognition and Brain MRI Markers of Structural Change in Adults in Mid- to Late-Life, Neurology (2026). DOI: 10.1212/wnl.0000000000214935

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 9:32am

Why some cancers are worse than others
Cancers with tetraploid cells—cells containing four chromosome sets—are associated with more aggressive tumor growth and poorer prognosis, partly due to recruitment of supportive stromal cells. Tumors with smaller tetraploid cells exhibit faster growth, greater invasiveness, and higher drug tolerance, with smaller cell size correlating with worse outcomes across multiple cancer types.

Most normal cells in your body are diploid, meaning they have two copies of each chromosome—one set from each parent.

To stay healthy, a diploid cell divides to make more diploid cells. But occasionally, a dividing cell makes a mistake, which throws off the chromosome numbers. And then, like an error at a printing press, that mistake is replicated and starts to accumulate.

This is one of the ways diseases like cancer can form.
Why do tetraploid cells make things so much worse?
Researchers saw that the number of tetraploid cells actually diminished during tumour formation in mice, and yet tumour mass ballooned fast and large.

In a first-of-its-kind discovery, they found that this growth was driven by the recruitment of stromal cells—non-cancerous connective tissue cells that provide structural support.

The presence of even a small fraction of these tetraploid cells can promote the recruitment of extra non-cancerous cells that support further tumour progression.
The second investigation initially targeted the physiology of tetraploid cells.
When the researchers made human-derived cancer cells tetraploid and isolated single-cell clones, he noticed something unexpected: the cells from the first few clones differed in size.

They anticipated all the clones to be two times larger than regular diploid cells because of the extra material crammed inside—but some were 25% to 30% smaller than expected.

And the smaller clones happened to be more tumorigenic than the large clones.
The smaller clones are more aggressive. They grow faster, are more invasive, and more tolerant of common anti-cancer and stress-inducing drugs."

Later experiments in mice showed that tumours with smaller tetraploid cells often increased more rapidly. Moreover, results did not depend on cancer cell type—they saw the same behaviour in colorectal and breast cancer.
The same things were identified even in human cancer cells.

Cimini, Daniela, Oxidative stress and serum deprivation influence the evolution of newly formed tetraploid cells during tumorigenesis, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2522077123. doi.org/10.1073/pnas.2522077123

Mathew Bloomfield et al, Cell and Nuclear Size Is Associated with Chromosomal Instability and Tumorigenicity in Cancer Cells That Undergo Whole Genome Doubling, Cancer Research (2026). DOI: 10.1158/0008-5472.can-24-3718

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 9:21am

Short exposures to common air pollutants have distinct impacts on lung function and brain activity, study shows
New research by a collaboration of scientists has revealed that common indoor and outdoor air pollutants can alter both brain and respiratory function within just four hours of exposure, offering key insights into how air pollution impacts brain health and may contribute to dementia risk.
Air pollution can influence the brain either directly, when harmful particles enter the brain, or indirectly, through inflammation in the lungs which then impacts the brain. Neurological diseases have been increasing for decades, and there is now a greater understanding that long-term exposure to elevated levels of air pollution is associated with dementia risk. While we often categorize air quality by the total amount of particulate matter, this new study demonstrates that the source of the pollution matters as much as the quantity.

Short-term exposure to different air pollution sources produces distinct effects on lung function and cognitive performance, even at identical particulate concentrations. Limonene-derived aerosols most strongly impaired lung function, while diesel exhaust and woodsmoke altered cognitive processing speed and executive function. These findings indicate that pollutant source and composition, not just total particulate matter, critically influence health impacts.
The findings published in npj Clean Air reveal that different pollutant sources produce varied health effects even at identical concentrations in the air. Recognizing these differences is essential for shaping public policy, improving clinical diagnoses and developing protective strategies. With an ever-growing aging population and increasing urbanization, the public-health imperative to mitigate neurological disease becomes increasingly urgent.
After 60 minutes of exposure, and a four-hour break, researchers assessed respiratory function alongside working memory, selective attention, socio-emotional processing, psychomotor speed and motor control.

Respiratory responses showed limonene had the greatest impact on lung function, followed by woodsmoke, diesel exhaust and finally cooking emissions.
Cognitive function was also found to be significantly influenced by pollutant sources. Diesel exhaust and woodsmoke improved processing speed; limonene-derived secondary organic aerosol enhanced working memory compared to cooking emissions; and diesel exhaust showed signs of impairing executive function. The team suggests that the presence of nitrogen oxides (NOX), known as vasodilators, may alter blood flow to the brain and contribute to these mixed cognitive effects.
Given that measurable effects were detectable after a brief 60-minute exposure, the findings suggest that prolonged exposure could have significant long-term consequences for brain health.

Thomas Faherty et al, Neurological and respiratory outcomes of the HIPTox controlled double-blind air pollution exposure trial, npj Clean Air (2026). DOI: 10.1038/s44407-026-00068-3

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 9:13am

Homo erectus may have left a genetic legacy in people today

Analysis of ancient tooth enamel proteins from East Asian Homo erectus fossils reveals a unique amino acid variant shared with Denisovans and present in modern Southeast Asian and Oceanian populations, indicating gene flow from H. erectus to Denisovans and subsequently to modern humans. These findings support a model of frequent interbreeding among archaic hominins, resulting in modern human genomes as mosaics of multiple ancestral lineages.

https://www.nature.com/articles/s41586-026-10478-8

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 8:50am

The 700-million-year history of our blood cells

Almost all animal species—including humans—have blood cells, but between different species our blood tells different stories. The lineage and components of blood cells vary widely, and this variety is a testament to how animals have evolved to protect themselves from infectious diseases.
Comparative gene expression analysis across animal species indicates that blood cells originated approximately 700 million years ago, with macrophage-like cells as the earliest form, derived from single-celled ancestors. The evolutionary lineage shows mast cells, T cells, red blood cells, and B cells subsequently branching from these ancestral macrophages, reflecting the deep evolutionary history of blood cell differentiation.
Thanks to advances in hematology and immunology, we now have detailed knowledge of the components and functions of both human and mouse blood cells. However, their evolutionary history has remained largely unknown. This inspired a team of researchers to investigate when and how blood cells originated, and how they diversified. The work appears in Proceedings of the National Academy of Sciences.

The team began by developing a new analytic method to compare gene expression profiles across various cell lineages and animal species. With this, they were able to construct phylogenetic trees of cell lineages and estimate the evolutionary history of these lineages in animals. They also included unicellular organisms in their comparison in order to trace the origin of blood cells back to possible single-celled ancestors.
Among the various lineages of human blood cells the team observed, macrophages showed the most striking resemblance to unicellular organisms, suggesting that early blood cells were macrophage-like. They then traced the gene FOS—commonly expressed in blood cells across animal species—back to a single-celled ancestor that lived 700 million years ago, suggesting that the first blood cells emerged around the same time as the onset of multicellular animals.

This finding implies that early animals generated the first blood cells by repurposing genetic material inherited from single-celled progenitors. The team's analysis also revealed that mast cells branched off from the macrophages, and that prototypic T cells and red blood cells subsequently branched off from the mast cells. Furthermore, prototypic B cells branched off from the macrophages after the segregation of mast cells.
Ultimately, the scientists were able to reconstruct the family tree of blood cells over a 700-million-year span, revealing that evolutionary history has been imprinted in our bodies as differentiation pathways of these cells. This work illustrates that the blood and immune cells circulating in our bodies can be considered a successful extension of the legacy left to us by our single-celled predecessors.
The researchers expect that the method developed in this study could help unravel the evolutionary origins of diseases such as cancer, leading to a better understanding of mechanisms and the development of new treatments.

Animals have expanded the evolutionary legacy of unicellular ancestors in blood cells, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2528110123

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 7:15am

Your brain doesn't forget when you forgive—it does something far more surprising with those painful memories

It is easy to say forgive and forget. But  brains don't work that way.

Forgiving someone might not erase painful memories, but it can subtly update them, making past hurts feel less upsetting. It's less "forgive and forget," and more "forgive and update."

Psychologists have long known that forgiveness is crucial for healing rifts and keeping social bonds strong. Folk wisdom even advises us to "forgive and forget" after a wrong, implying that saying you forgive someone should make the bad memory vanish.

But forgiving doesn't actually make you forget, say neuro-scientists.

When you forgive someone for a wrongdoing, you don't forget the event. But once you forgive, the memory doesn't hurt as much. Indeed, past studies hinted that forgiving someone can blunt the memory of their misdeed. What hasn't been clear is how that happens in the brain. Is the memory simply erased, or does it get rewritten?

To test this, researchers staged a simple forgiveness experiment under an fMRI scanner.

What is happening in the mind that is forgiving?

The fMRI scans pointed to two key brain areas lighting up during these forgiveness trials. One was the dorsomedial prefrontal cortex (DMPFC), a region known for "mentalizing," thinking about another person's perspective and intentions. The other was the posterior hippocampus, a zone crucial for storing detailed episodic memories.

When volunteers forgave, the activity patterns in these areas during the second-day viewing of an image looked much like the patterns during the first-day forgiveness of that image. In other words, the brain seemed to have folded the new forgiving perspective into the original memory.

The data showed that "information from the moment of forgiveness becomes incorporated into the memory" of the event. The authors summarize it neatly: "Instead of 'forgive and forget,' forgiveness may involve a 'forgive and update' process, revising memories to aid reconciliation."

When we forgive, we create a new story (e.g., "they had a reason and are sorry") that gets woven into the old memory. By the next day, thinking of the situation has a slightly altered version where you can sympathize with the offender and feel less enraged.

What does that mean?

The findings suggest that the brain's natural learning and memory system is at play: just as a new fact learned soon after an event can slip into the original memory (a process known as reconsolidation), forgiving someone seems to insert empathy and context into our recollection.

As of now, the message is one of hope; forgiving may not make someone literally forget a hurt, but it can make it hurt less. This could explain why people feel lighter and more peaceful after successfully forgiving someone. Promoting forgiveness might be a subtle way to edit painful memories, not erase them altogether.

Songzhi Wu et al, Forgiveness updates interpersonal memories to be less negative., Emotion (2026). DOI: 10.1037/emo0001611

Comment by Dr. Krishna Kumari Challa on May 26, 2026 at 7:01am

A distinct communication subspace in the brain turns goals into actions

Humans continuously adapt their actions and behaviours in response to changes in their surrounding environment. Past neuroscience studies suggest that this adaptation process relies on the brain's ability to translate abstract goals or rules into specific physical actions or behaviours, yet its neural underpinnings have not yet been clearly elucidated.

Adaptive behaviour relies on the ability to translate abstract rules and goals into actions suited to the current context.

Researchers  recently carried out a study aimed at better understanding how context-related mental representations in a region of the brain known as the prefrontal cortex (PFC) are transformed into movement plans, which are processed in the primary motor cortex (M1). Their findings, published in Nature Neuroscience, led to the identification of a distinct communication subspace that links the PFC and M1, through which contextual information that can inform the planning of actions is transmitted.

Neha Binish et al, A communication subspace relays context-dependent actions from human prefrontal to motor cortex, Nature Neuroscience (2026). DOI: 10.1038/s41593-026-02290-4.

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