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Comment by Dr. Krishna Kumari Challa 16 hours ago

The sleep switch: How one brain signal turns sleep on and off

Researchers showed that a single brain signal acts like a biological switch—both triggering sleep and ending it.

Their findings, published in the journal Current Biology, were made possible by studying a tiny roundworm, C. elegans, a powerful model organism in biology.

We know that falling asleep and waking up is controlled by a special set of brain cells, called sleep neurons. However, we don't know how exactly they control the downstream molecular pathways to make us fall asleep and wake up again until now.

Researchers turned to C. elegans to answer these questions. In contrast to humans, who have thousands of sleep neurons that control sleep, C. elegans needs just one neuron to do this job. This simplicity makes it a perfect model organism to study the principal molecular pathways controlling sleep.

This research sheds light on one of the fundamental questions in biology: how organisms regulate sleep and wakefulness. By understanding the fundamental molecular machinery behind sleep, researchers can better understand sleep disorders such as narcolepsy and insomnia that have a major impact on quality of life. The findings also add to the growing body of evidence that even simple model organisms can reveal fundamental mechanisms that govern life.

The team focused on a chemical messenger called FLP-11. When a sleep neuron activates, it releases FLP-11. Such chemical messengers work like molecular "notes" that are passed between brain cells to deliver different commands.

Through genetic screening, the researchers identified a key receptor, called DMSR-1, that FLP-11 binds to deliver its message. If this receptor was missing from the brain, researchers observed that the worms slept significantly less. DMSR-1 turned out to be present in different types of neurons. Depending on which neuron received the message, the results were dramatically different.

They discovered that FLP-11 activates DMSR-1 receptors in two completely different types of neurons.  They found the receptor present in neurons that promote wakefulness. When activated by FLP-11, the receptor turns off the wakefulness neurons. This, in turn, helps the worm fall asleep. On the other hand, the receptor is also present in the sleep neuron itself. Here, it also turns it off, which ultimately wakes the animal back up.

In other words, the same chemical that puts the worm to sleep also helps wake it up again, simply by targeting different cells in the brain. It is an efficient mechanism that controls the start of sleep while also keeping its duration in check.

Unlike humans, C. elegans have much shorter sleep phases that last only around 20 minutes. However, sleep is such a fundamental biological process that many molecules and mechanisms involved in sleep are shared across species. We don't yet know if the same sleep switch exists in humans, but it provides a promising clue in the search for mechanisms that control sleep in our species

Lorenzo Rossi et al, The neuropeptide FLP-11 induces and self-inhibits sleep through the receptor DMSR-1 in Caenorhabditis elegans, Current Biology (2025). DOI: 10.1016/j.cub.2025.03.039

Comment by Dr. Krishna Kumari Challa 16 hours ago

Harmful effects of gas cookers on health and the environment reviewed in report

Researchers put the magnitude of the problem into perspective by providing figures on the number of children with asthma and premature deaths associated with the use of gas cookers, and highlighted the need for measures and policies to reduce emissions from these appliances.

Environmental pollution is combined with fumes from gas cookers during normal use, and are believed to be the cause of  thousands of premature deaths.

They recommend electric cooking and induction cookers. 

 Assessment of the health impacts and costs associated with indoor nitrogen dioxide exposure related to gas cooking in the European Union and the United Kingdom, repositori.uji.es/items/156fbd … a4-9856-9415513d505f

Comment by Dr. Krishna Kumari Challa yesterday

But when conflicts of interest take hold, even researchers cook up research results.

Will the companies that make these products stop using these 'chemicals'?

we are in the twilight zone now, neither here, not there. After knowing this, we have to take our own decisions now.

I am making my own ice creams now, without using any harmful chemicals.  I am making my own other things too. They might not be like the ones we buy outside. But  they are good for my health.  That is enough for me.

What about you? 

Sources: Microbiome, British medical journal, PLoS Medicine and medical express with inputs from Sci-Art Lab.

Part 4

Comment by Dr. Krishna Kumari Challa yesterday

For a consumer, trying to steer clear of emulsifiers can be difficult. Without realizing it, people can consume a variety of emulsifiers from a variety of foods—and the same chemicals from multiple sources.

Polysorbate 80 alone was listed as an ingredient on the labels of 2,311 products!
Carrageenan was listed on 8,100 product labels; maltodextrin, 12,769; and xanthan gum, 17,153.
Some emulsifiers have multiple names, making them harder to recognize. Some names can apply to more than one emulsifier. Controllers find it difficult to identify them.
Carboxymethyl cellulose—not to be confused with methyl cellulose—is also known as carboxymethylcellulose and cellulose gum. Maltodextrin can be derived from substances such as cornstarch, rice starch, and wheat starch—but the FDA doesn't consider it synonymous with the term "modified food starch."

The naming practices can frustrate efforts to track the chemicals in food, to measure how much of the stuff people are taking in, and even to figure out precisely which chemicals a scientific study evaluated, researchers say.
And there is a hell lot of confusion everywhere!
The very term "emulsifier" is problematic. By strict definition, emulsifiers create an emulsion—a stable blend of liquids that would not otherwise mix, such as oil and water. However, the term is used broadly, encompassing chemicals such as maltodextrin that thicken, stabilize, or alter texture.

Emulsifiers can be found in foods marketed as natural or healthy as well as ones that look artificial. Some products contain multiple emulsifiers.

Research on emulsifiers has been building in recent years.

For instance, a study published in January this year by the Journal of Crohn's and Colitis concluded that a diet low in emulsifiers is an effective treatment for mild or moderate Crohn's disease. 

A study published in February 2024 in the journal PLOS Medicine found that higher intakes of carrageenan and mono- and diglycerides of fatty acids were associated with higher risks of cancer. The study observed 92,000 French adults for an average of 6.7 years.

A study published in September 2023 in The BMJ, formerly known as the British Medical Journal, found that intake of several types of emulsifiers was associated with the risk of cardiovascular disease. The study observed more than 95,000 French adults for a median of 7.4 years.

A series of earlier studies found that emulsifiers "can promote chronic intestinal inflammation in mice"; that two in particular, carboxymethyl cellulose and polysorbate 80, "profoundly impact intestinal microbiota in a manner that promotes gut inflammation and associated disease states"; and that, based on a laboratory study of human samples, "numerous, but not all, commonly used emulsifiers can directly alter gut microbiota in a manner expected to promote intestinal inflammation," as recounted in a 2021 paper in the journal Microbiome.

Part 3

Comment by Dr. Krishna Kumari Challa yesterday

The scientific findings come with caveats. For instance, much of the research has been done in mice, or by mimicking the human gut in a tube. There are many unknowns. Not all emulsifiers have bad effects, or the same effects, and some people are thought to be much more vulnerable than others.

Even some researchers who have co-authored papers say that it's too soon to say regulators should ban them.

Still, the research poses a challenge.

 When emulsifiers began spreading through the food supply, controllers weren't focusing on the gut microbiome, a relatively recent scientific frontier, researchers say. The scenario changed now as science progressed. We cannot use old excuses.

There's a body of research now that suggests concern with some of these ingredients. These chemicals are creating an inflammatory response in the gastrointestinal tract, and with an altered microbiome lining that GI tract, kids feel sick, report the medical doctors.

Same is true for petroleum-based food dyes too. 

As far back as 2020, an international organization for the study of inflammatory bowel diseases advised that, for people with those conditions, it "may be prudent to limit intake" of maltodextrin, carrageenan, carboxymethyl cellulose, and polysorbate 80.

Emulsifiers are developed from a variety of sources, including plants and bacteria.

Some ingredients that might affect the microbiome show up in foods because they were deemed "generally recognized as safe.

But new information does at any time require reconsideration. Doesn't it?

Earlier these  substances "fell within the standards" when they were greenlighted.

These chemicals were "never considered before for the potential effect on the microbiota".

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Researchers say emulsifiers may cause a variety of health problems

The difference between commerce and science: Commerce wants to sell its products by showing you eye and attention catching ads and videos, while  science tries to see what lies behind the masks and makes people alert. 

Which one do you listen to and which one do you follow?

Ice cream that resists melting. Great, you would think and buy  the thing that  can make this possible.

'But, wait', says science. Why?

This is the actual scene playing out before you:

 In a video explaining the science behind it, a seller of food chemicals shows scoops of ice cream holding their shape under hot lights. The super ingredient? Polysorbate 80.

Polysorbate 80 is an emulsifier, a chemical used to control the consistency of thousands of supermarket products. Other widely used emulsifiers or stabilizers include carboxymethyl cellulose, carrageenan, and maltodextrin.

Emulsifiers and thickening agents play an important role in improving food texture and consistency.

Recently, such ingredients have been showing up in scientific studies for another reason: Researchers say they may cause a variety of health problems.

Studies have found that emulsifiers can alter the mix of bacteria in the gut, known as the microbiome or microbiota; damage the lining of the gastrointestinal tract; and trigger inflammation, potentially contributing to problems elsewhere in the body.

Emulsifiers and stabilizers are among the most common ingredients in ultraprocessed foods. But could you ban them?

This is the complexity of the war on food additives. 

The researchers show how, when it comes to food science, regulators are chronically playing catch-up. In the meantime, for many ingredients, regulators and consumers alike are left in a gray zone between suspicion and proof of harm in humans.

Emulsifiers' assault on the microbiome could help explain inflammatory bowel diseases such as Crohn's disease and ulcerative colitis, metabolic disorders, and even cancer, the studies suggest.

"There is a lot of data showing that those compounds are really detrimental to the microbiota and that we should stop using them," say the several studies on them.

But solid proof?!

Yet much larger and more ambitious clinical trials in humans are needed to get it.

Wait, we  some evidence from doctors and patients. 

For people who  suffered from gastrointestinal illness, the research fits their own experience as a consumer. Changing their diet to avoid emulsifiers has made a shocking difference, easing symptoms that were debilitating. 

Clinically, many patients have reported an improvement in symptoms with such changes, say the gastroenterologists.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

Previous studies have shown reproduction-like behaviors such as polymerization-induced self-assembly (PISA) in micelles and vesicles. However, these processes were neither biochemistry-free nor did they demonstrate true autonomous self-reproduction.

To explore the unknown, the team designed a one-pot PISA batch reactor consisting of strictly non-biochemical molecules with an aim to synthesize amphiphiles that can self-organize, self-assemble, and self-initiate into chemically active entities.

The reaction vial included an aqueous solution of a hydrophilic polymer with a hydrophobic chain transfer agent molecule (CTA) attached to its end, along with the monomer to be polymerized and a photocatalyst in a nitrogen-filled inert environment. This mixture was then allowed to sit under green LED light for 90 minutes at 33°C.

They observed that the mixture of chemicals undergoes photo-Reversible Addition-Fragmentation Chain Transfer (RAFT) photopolymerization in water to transform the starting molecules into amphiphilic block copolymers. These block copolymers then gave rise to non-biochemical polymer vesicles or synthetic cells that displayed self-reproduction behavior via PISA.

The vesicles not only formed and sustained themselves but also released polymeric "spores" that seeded a nonlinear, exponential increase in vesicle numbers, with each new generation inheriting certain properties from their "parent" vesicles.

The behavior shown in this study mimics self-reproduction—a key feature of living systems—arising from simple chemistry without the need for complex biochemical processes.

The researchers note that the findings not only offer insights into how life might have begun but also open new possibilities for creating a wide range of abiotic, life-like systems.

Sai Krishna Katla et al, Self-reproduction as an autonomous process of growth and reorganization in fully abiotic, artificial and synthetic cells, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2412514122

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Artificial cell-like structures mimic self-reproduction and release polymeric spores

Life on Earth possesses an exceptional ability to self-reproduce, which, even on a simple cellular level, is driven by complex biochemistry. But can self-reproduction exist in a biochemistry-free environment?

A study by researchers  demonstrated that the answer is yes.

The researchers designed a non-biochemical system in which synthetic cell-like structures form and self-reproduce by ejecting polymeric spores.

The PNAS paper reports a one-pot reaction in which chemically active polymer protocells began their journey as a uniform mixture of molecules that usually do not self-assemble. However, when placed under green light (530 nm), they formed vesicle-like structures that grew and divided as the reaction proceeded.

Living organisms produce offspring from their own cellular material, giving rise to new, independent life forms which interact with their environment to obtain food, energy, and information needed for survival. If all goes well, the internal chemical networks of these new systems also enable them to self-reproduce, leading to future generations. As Rudolf Virchow, father of cellular pathology, stated in 1858, "every cell comes from a pre-existing cell."

In biochemistry-based life, even single-celled organisms like bacteria depend on a chain of well-coordinated complex chemical processes to run the life-sustaining processes and reproduction.

It is known that biochemistry is sufficient for driving self-reproduction, but is it essential? Or can we build artificial, compartmentalized chemical systems in the lab that can self-assemble and reproduce on their own?

Part 1

Comment by Dr. Krishna Kumari Challa on Thursday

By elucidating the neural basis of individual differences in fear plasticity, this study highlights the central role of brain states in stress adaptation.

Xuemei Liu et al, Neural circuit underlying individual differences in visual escape habituation, Neuron (2025). DOI: 10.1016/j.neuron.2025.04.018

Part 2

Comment by Dr. Krishna Kumari Challa on Thursday

Neural circuit mechanism may explain why people have different fear levels

In a study published in Neuron, a research team revealed the neural circuit underlying individual differences in visual escape habituation.

Emotional responses, such as fear behaviors, are evolutionarily conserved mechanisms that enable organisms to detect and avoid danger, ensuring survival. Since Darwin's "On the Origin of Species" (1859) proposed that individual differences drive natural selection, understanding behavioral adaptation has become essential for unraveling biodiversity and survival strategies.

Repeated exposure to predators can elicit divergent coping strategies—habituation or sensitization—that are dependent on sensory inputs, internal physiological states, and prior experiences. However, the neural circuits underlying individual variability in the regulation of internal states and habituation to repeated threats remain poorly understood.

To address this question, researchers employed advanced techniques such as in vivo multichannel recording, fiber photometry, pupillometry and optogenetic manipulation to investigate how individual differences in arousal and internal states influence visual escape habituation.

Researchers found that distinct subcortical pathways from the superior colliculus to the amygdala and insula cortical pathways that govern two visual escape behaviors in two groups of mice. They identified two distinct defensive behaviors—sustained rapid escape (T1) and rapid habituation (T2).

T1 involves the superior colliculus (SC)/insular cortex-ventral tegmental area (VTA)-basolateral amygdala (BLA) pathway, whereas T2 relies on the SC/insula-dorsomedial thalamus (MD)-BLA circuit. The MD integrates inputs from the SC and insula to regulate arousal and fear responses, while beta oscillations in BLA modulate fear states.
Dysregulation of innate fear circuits is closely linked to many mental health conditions, including phobias, anxiety, and post-traumatic stress disorder (PTSD). Elucidating the neural circuitry underlying innate fear not only enhances our understanding of emotional disorders but also provides promising therapeutic targets for clinical interventions.

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