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Yahoo
2 days ago
- General
- Yahoo
Can adults grow new brain cells?
When you buy through links on our articles, Future and its syndication partners may earn a commission. The developing human brain gains billions of neurons while in the womb, and tacks on some more during childhood. For most of the 20th century, the conventional wisdom was that the brain cells grown before adulthood would be the only ones we would have for the rest of our lives. But over the past few decades, more and more research is challenging that belief. So is it actually possible for adults to grow neurons? While some experts believe there's strong evidence that we can gain brain cells after childhood, others are still skeptical of this notion. The process of creating new brain cells is called neurogenesis. Researchers first observed neurogenesis after birth in lab animals of various ages, including mice, rats and songbirds. In adult mice, they found new neurons growing in parts of the brain collectively called the subventricular zone, an area closely linked with sense of smell, as well as in the hippocampus, a structure that's central to memory. Researchers think that neurogenesis in these brain regions is important for plasticity, or the brain's ability to adapt and change over time. Plasticity underlies the ability to learn and form memories, for instance. In mice, it's clear that lifestyle factors such as living in a stimulating environment and exercising can promote the growth of new neurons. Conversely, in mouse models of diseases like Alzheimer's, neurogenesis is hampered. What's still up for debate is whether these findings extend beyond mice and other lab animals. "Most of our knowledge about adult neurogenesis came from studies in animal models," Hongjun Song, a professor of neuroscience at the University of Pennsylvania Perelman School of Medicine, told Live Science in an email. "Whether such knowledge can be directly translated to human studies is a challenge." That's because many of the studies that have established the existence of adult neurogenesis in animals used methods that aren't possible in human studies, such as injecting radioactive tracer molecules into the brain. These methods enable scientists to visualize if and where new neurons are growing, but the tracers themselves can be toxic. These methods also require dissecting the brain after the animal has been euthanized. "Unfortunately, there is no way to measure neurogenesis in the living person yet," Gerd Kempermann, a professor of genomics of regeneration at the Center for Regenerative Therapies in Dresden, Germany, told Live Science in an email. Related: Is there really a difference between male and female brains? Emerging science is revealing the answer. There are, however, some rare cases in which scientists have been able to apply similar methods to track neurogenesis in humans. For example, the radioactive tracer molecules used in animal neurogenesis studies are also sometimes used by doctors to track tumor growth in patients with brain cancer. While these radioactive tracer molecules are too toxic to give to healthy people, their benefits outweigh their risks in patients who already have cancer. Scientists behind a 1998 study published in the journal Nature Medicine used this approach and analyzed the brains of cancer patients after their deaths. They reported that, in addition to flagging cancer cells, the tracer molecules had marked new neurons in the hippocampus. This finding suggested that humans could grow new neurons well into adulthood, given the patients were 57 to 72 years old. Later, a 2013 study in the journal Cell used a form of radiocarbon dating to look for new neurons in humans. Radiocarbon dating usually determines the age of a sample by comparing the relative proportion of two different forms of carbon, or carbon isotopes, called carbon-14 and carbon-12. But to study neurogenesis in humans, scientists instead looked at carbon-14 concentrations inside the DNA of cells. Their approach took advantage of the fact that there was a spike in carbon-14 levels in the atmosphere caused by nuclear bomb tests in the 1950s and 1960s. People's bodies absorbed this carbon-14 via their diets, and it became incorporated into their DNA. The amount of carbon-14 in a given cell corresponds to the isotope's concentrations in the atmosphere at the time the cell formed, making it possible to roughly pinpoint the "birthday" of that cell — and determine whether it formed after its owner's birth. By analyzing postmortem brain tissue from people ages 19 to 92, this radiocarbon study identified newborn neurons in the adult hippocampus. But while compelling, the study's methods were so complex that the results have never been replicated. That said, there are also more indirect markers of neurogenesis, such as certain proteins that are only present in growing neurons. Using these methods, both Kempermann and other research groups have uncovered additional evidence of newborn neurons in the adult human brain. "There are many different markers that are more or less specific for adult neurogenesis," Kempermann said. "In tissue sections, one can study these markers under the microscope and look for patterns that are consistent with neuronal development." But some researchers aren't convinced by this evidence. Arturo Alvarez-Buylla, a professor of neurological surgery at the University of California, San Francisco, has spent his career studying the growth of new neurons. While he's observed new neurons being formed in children and adolescents, he's found little evidence to support the notion of neurogenesis in adults. Alvarez-Buylla believes there are a number of issues that may lead other researchers to find signs of neurogenesis in adult humans. For example, the chemical markers that some labs use to track new neurons may also show up in other cell types, such as glia, which are cells in the brain that support neurons' function in various ways. This may make it appear that new neurons are growing when they're actually not. He's also skeptical of the use of carbon-14 dating for this purpose, calling it "creative" but arguing that researchers can't confirm that the new cells are neurons, or if there could be other potential reasons for varying carbon-14 levels in cells. But Alvarez-Buylla isn't ruling out the possibility of human adult neurogenesis; he's only saying that — so far — the evidence hasn't convinced him. "I would say that is a rare phenomenon," said Alvarez-Buylla. "If it happens, it's very, very few cells." Kempermann, on the other hand, is a firm believer that people can grow new neurons well into adulthood. "The positive reports outnumber the critical papers by far, their take is much wider, and their quality is overall higher." The researchers said that understanding whether adult neurogenesis exists will continue to be a key question for the field of neuroscience. RELATED STORIES —Could we ever retrieve memories from a dead person's brain? —What happens in your brain while you sleep? —How much of your brain do you need to survive? "The question about whether adults can grow new neurons has tremendous implications for the plasticity of the adult brain," Song said. If new neurons can be grown and integrated into the brain, he explained, those mechanisms could form the basis for new therapies for a variety of conditions, including brain injuries and neurodegenerative disorders. Alvarez-Buylla said that even if he doesn't believe neurogenesis happens frequently in adults, it may nonetheless be possible to harness the mechanisms used by animals to grow new neurons for human therapies. "The whole idea that it can happen opens a huge door for repair," he said. "I hope that we can keep our plasticity open to things going either way."
The Independent
5 days ago
- Health
- The Independent
Drug combination found to extend lifespan by 30 per cent
A combination of two cancer drugs significantly boosts lifespan in mice, according to a new study that may lead to better strategies for longevity. The drugs rapamycin and trametinib given together as a combination can increase mice lifespan by up to 30 per cent, say researchers, including from the Max Planck Institute for Biology of Ageing. Trametinib alone can extend lifespan by 5 to 10 per cent and rapamycin by 15–20 per cent, according to the study published in the journal Nature Ageing. Researchers say the drug combination has several other positive effects on mice health in old age, including less chronic inflammation in tissues and a delayed onset of cancer. Previous studies showed potent anti-ageing effects of rapamycin in several animals. Trametinib wasn't known to extend lifespan in mice but previous research in flies indicated it might. In humans, the two drugs have been used for cancer treatment. While both drugs act on the same chemical network in the body, their combination appears to achieve novel effects that are likely not attributable to just an increase in dosage. Gene activity analysis of mice tissues shows the combination influences genes differently than is achieved by administering the drugs individually. The analysis reveals specific gene activity changes that are only caused by the combination of the two drugs. In further studies, researchers hope to determine the optimal dose and route of administration of trametinib to maximise its life-prolonging effects while minimising unwanted side effects. 'Trametinib, especially in combination with rapamycin, is a good candidate to be tested in clinical trials as a geroprotector,' Sebastian Grönke, a co-author of the study, says. 'We hope that our results will be taken up by others and tested in humans. Our focus is on optimising the use of trametinib in animal models.' While the exact same kind of effect may not be possible in humans, researchers hope the drugs can help people stay healthy and disease-free for longer in life. "Further research in humans in years to come will help us to elucidate how these drugs may be useful to people and who might be able to benefit,' British geneticist Dame Linda Partridge said in a statement. Scientists hope the drug combination may be developed into a promising strategy for combating age-related diseases and promoting longevity.
Sustainability Times
27-05-2025
- Science
- Sustainability Times
See in Total Darkness: Infrared Contact Lenses Let Humans Detect Night Vision Even With Eyes Fully Shut
IN A NUTSHELL 👁️ Researchers have developed innovative contact lenses that allow humans to perceive infrared light , enhancing vision capabilities. , enhancing vision capabilities. 🐭 Initial tests on mice and humans showed successful infrared detection , with improved signal interpretation when eyes are closed. , with improved signal interpretation when eyes are closed. 🔬 The lenses use nanoparticle technology to convert near-infrared wavelengths into visible light, opening up new visual possibilities. to convert near-infrared wavelengths into visible light, opening up new visual possibilities. 🔒 Potential applications span security, accessibility for the visually impaired, and communication, offering transformative benefits across various domains. The realm of human vision is on the brink of a revolutionary breakthrough, thanks to the development of innovative contact lenses that allow humans to perceive infrared light. These lenses, requiring no external power source, promise to unlock a world previously unseen by the naked eye. As researchers push the boundaries of wearable technology, these lenses may soon become a staple for various applications, ranging from security enhancements to aiding the visually impaired. This groundbreaking technology offers a glimpse into a future where human capabilities are enhanced beyond current limitations. Mice, Morse Code, and Multi-Color IR Detection In the quest to create superhuman vision, researchers have successfully tested their infrared-detecting contact lenses on both mice and humans. The lenses allowed mice to perceive infrared light, prompting behavioral changes such as avoiding illuminated zones, a clear indicator of infrared perception. When applied to human trials, participants could decipher Morse-code-like signals from infrared LED sources, judging the direction of incoming signals accurately. Notably, participants experienced improved infrared vision when they closed their eyes, as near-infrared (NIR) light penetrates the eyelid more effectively than visible light. This fascinating development underscores the potential of these lenses to enhance human perception in unique ways. By fine-tuning the nanoparticles within the lenses, researchers enabled users to distinguish between different NIR wavelengths, effectively adding a color-coding capability to the technology. This ability to perceive color variations in infrared light opens up new possibilities for communication and information transmission, making these lenses a versatile tool in numerous fields. 'Mach 6 From a Runway': US Unveils Hypersonic Jet Engine That Could Redefine Military Airpower and Global Strike Speed Looking Ahead: Better Resolution and Broader Applications While the development of infrared contact lenses marks a significant leap forward, challenges remain. The proximity of the lenses to the retina causes light scattering, which reduces image sharpness. To address this, researchers have also developed a goggle-style wearable using the same nanoparticle technology, which offers enhanced resolution. This alternative form factor could prove valuable for tasks requiring more precise visual acuity. The current iteration of lenses is limited to detecting strong NIR emissions from LED sources. Enhancing their sensitivity to ambient infrared radiation in natural environments is a key focus for future research. Collaborations with materials scientists and optical experts aim to create contact lenses with improved spatial resolution and heightened sensitivity, paving the way for even broader applications. 'Mind-Controlled Roaches Are Real': Scientists Use UV Helmets to Wirelessly Command Cockroach Cyborgs in Chilling New Experiment Nanoparticle Technology: The Engine Behind Super Vision At the heart of these groundbreaking contact lenses lies the sophisticated use of nanoparticles. These specialized particles are embedded into soft contact lenses, where they convert NIR wavelengths into visible light. Emitting light in the 400–700 nm range, these particles enable wearers to perceive infrared sources as distinct visual signals. This conversion process is what allows the lenses to transform invisible infrared light into something visible to the human eye. The versatility of nanoparticle technology extends beyond just infrared detection. By converting red visible light into green, this technology could also assist individuals with color blindness, making previously indistinguishable hues visible. The potential applications of these lenses are vast, and as the technology matures, it may offer solutions to a range of visual impairments and challenges. UK Unleashes Instant Drug Scanner: New High-Tech Street Weapon Can Detect Narcotics Before They're Even Consumed Potential Applications: Security, Accessibility, and Beyond The implications of infrared contact lenses are profound, offering transformative benefits across multiple domains. In security and rescue operations, the ability to perceive flickering infrared signals could facilitate covert communication and information transmission. Encryption and anti-counterfeiting measures could also benefit from the unique capabilities of these lenses. For the visually impaired, the lenses may provide a novel form of assistance, enabling them to perceive visual cues that were previously inaccessible. As the technology evolves, its applications are likely to expand, offering enhanced vision to a wider audience. The lenses represent a significant step toward non-invasive wearable devices that bestow superhuman capabilities, enriching our interaction with the world around us. As the development of infrared contact lenses continues to advance, the possibilities for enhancing human vision seem boundless. With ongoing research and collaboration, these lenses could soon become a ubiquitous tool, reshaping how we perceive and interact with our environment. What other breakthroughs in wearable technology might lie on the horizon, waiting to change the way we experience the world? Our author used artificial intelligence to enhance this article. Did you like it? 4.5/5 (21)
The Sun
15-05-2025
- Health
- The Sun
Humans 'emit mysterious light that disappears when we die' – as scientists say we really do ‘glow' with health
HUMANS do actually glow with health, according to scientists, as a new study suggests our bodies emit an extremely faint light that goes out when we die. It's not just humans either - but seemingly all life. 3 3 A new experiment on mice and plants, from the University of Calgary and the National Research Council of Canada, found that both lifeforms exhibit physical evidence of an eerie 'biophoton'. Biophotons, or ultra-weak photons, are tiny particles of light emitted by living organisms. But this light - which is so faint it cannot be seen by the naked eye - is extinguished under extreme stress or death, University of Calgary physicist Vahid Salari and his team have claimed. Researchers found they could capture the biophotons emitting from mouse cells before and after death in the visible band of light. There was a significant difference in the numbers of these photons in the period before and after the mice were euthanised. The study was also carried out on thale cress and dwarf umbrella tree leaves, to reveal similar results. Stressing the plants by crushing them showed strong evidence that reactive oxygen species could in fact be behind the soft glow. "Our results show that the injury parts in all leaves were significantly brighter than the uninjured parts of the leaves during all 16 hours of imaging," the researchers wrote in their report. A separate 2009 study also suggested that humans are bioluminescent. 'The human body literally glimmers,' study authors wrote at the time. 'The intensity of the light emitted by the body is 1000 times lower than the sensitivity of our naked eyes.' Salari and his team believe that being able to monitor this healthy glow could eventually provide medical specialists with a powerful, non-invasive research or diagnostics tool. It could offer a new way to remotely monitor the stress of individual tissues in whole human or animal patients. Alternatively, it could even work among crops or bacterial samples. 3
The Independent
10-05-2025
- Health
- The Independent
The bizarre reason some people are fine on just four hours of sleep a night
Scientists identified a rare gene mutation (N783Y in the SIK3 gene) that allows some individuals to function well on only 4-6 hours of Sleep. This mutation affects a phosphate exchange process crucial to the Sleep -wake cycle, leading to less Sleep and potentially more deep Sleep. Mice with the same mutation slept 30 minutes less than unaltered mice, confirming the gene's role in Sleep duration. This discovery could lead to new therapies for Sleep disorders and improve Sleep quality. The mutation seems to increase deep Sleep in those who have it.
