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Emily Horwitz

UK, Japan scientists win Nobel for stem cell breakthroughs | Reuters - 0 views

www.reuters.com/...medicine-idUSBRE8970AB20121008

science reuters ethics stem cells research nobel

shared by Emily Horwitz on 08 Oct 12 - No Cached
  • Scientists from Britain and Japan shared a Nobel Prize on Monday for the discovery that adult cells can be transformed back into embryo-like stem cells that may one day regrow tissue in damaged brains, hearts or other organs.
  • discovered ways to create tissue that would act like embryonic cells, without the need to harvest embryos.
  • "These groundbreaking discoveries have completely changed our view of the development and specialization of cells," the Nobel Assembly at Stockholm's Karolinska Institute said.
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  • big hope for stem cells is that they can be used to replace damaged tissue in everything from spinal cord injuries to Parkinson's disease.
  • Scientists once thought it was impossible to turn adult tissue back into stem cells, which meant that new stem cells could only be created by harvesting embryos - a practice that raised ethical qualms in some countries and also means that implanted cells might be rejected by the body.
  • The new stem cells are known as "induced pluripotency stem cells", or iPS cells.
  • "We would like to be able to find a way of obtaining spare heart or brain cells from skin or blood cells. The important point is that the replacement cells need to be from the same individual, to avoid problems of rejection and hence of the need for immunosuppression."
  • Thomas Perlmann, Nobel Committee member and professor of Molecular Development Biology at the Karolinska Institute said: "Thanks to these two scientists, we know now that development is not strictly a one-way street."
  • "You can't take out a large part of the heart or the brain or so to study this, but now you can take a cell from for example the skin of the patient, reprogram it, return it to a pluripotent state, and then grow it in a laboratory," he said.
sissij

The Stem-Cell Revolution Is Coming - Slowly - The New York Times - 3 views

www.nytimes.com/...hinya-yamanaka-stem-cells.html

new york times science social media

shared by sissij on 17 Jan 17 - No Cached
  • In 2001, President George W. Bush issued an executive order banning federal funding for new sources of stem cells developed from preimplantation human embryos. The action stalled research and discouraged scientists.
  • re-energized the field by devising a technique to “reprogram” any adult cell, such as a skin cell, and coax it back to its earliest “pluripotent” stage. From there it can become any type of cell, from a heart muscle cell to a neuron.
  • But it’s a double-edged sword. After multiple cell cycles, the chances of mutations increases.
  • sissij on 17 Jan 17
     
    In Biology, we learned that the study for stem cells has been halted because of the ethic issues on whether embryos should be count as human life. Now, there is this new technique that can induce skin cello its earliest "pluripotent" stage. With this technique,the study of stem cells and continue and flourish to benefit patients who need to have new cells that aren't mutated. It's surprised to see that how fast science is progressing. The science wielder at school might not be the science up to date.--Sissi (1/17/2017)
sissij

New Prospects for Growing Human Replacement Organs in Animals - The New York Times - 0 views

www.nytimes.com/...chimera-stemcells-organs.html

new york times science research

shared by sissij on 28 Jan 17 - No Cached
  • For the first time, biologists have succeeded in growing human stem cells in pig embryos, shifting from science fiction to the realm of the possible the idea of developing human organs in animals for later transplant.
  • Since the organ would be made of a patient’s own cells, there would be little risk of immune rejection.
  • They would be generated by implanting human stem cells into an early pig embryo, resulting in an animal composed of mixed pig and human cells.
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  • The two reports together establish the feasibility of trying to grow replacement human organs in animals, though such a goal is still far off.
  • Creating chimeras, especially those with human cells, may prove controversial, given the possibility that test animals could be humanized in undesirable ways. One would be if human cells should be incorporated into a pig’s brain, endowing it with human qualities. Almost no one wants a talking pig.
  • The ban is still in place, and it’s unclear whether the Trump administration would continue to consider lifting the moratorium or whether new objections would be raised to using public funds for this line of research.
  • But no one knows exactly what sequence of chemicals is required for the generation of each different tissue or organ. This may be why glassware experiments with stem cells have not yet lived up to their full promise.
  • Concern about human cells’ incorporation into a lower animal’s brain is not without basis. Dr. Steven Goldman of the University of Rochester Medical Center found in 2013 that mice injected with a special type of human brain cell had enhanced learning abilities.
  • sissij on 28 Jan 17
     
    The ethics in biology is always a controversial issue in the research. In biology, we want to get as close to the truth as we possibly can, but that sometimes means that we have to research on things that are considered to be inhumane. This article talks about a new possibility that we can grow human stem cells in animals. That would lead to a potential problem of animals gaining intelligence. If animals start to have human properties, how would we treat them? Will they be a threat to our identity? And also, through the experiment described in the article, we can see that the scientific method in biology is dealing with probabilism and population. It is always gathering data. They are always ready for exceptions. --Sissi (1/28/2017)
dicindioha

A New Form of Stem-Cell Engineering Raises Ethical Questions - The New York Times - 0 views

www.nytimes.com/...-synthetic-embryos-sheefs.html

ESCdevelopment ethics

shared by dicindioha on 24 Mar 17 - No Cached
  • researchers at Harvard Medical School said it was time to ponder a startling new prospect: synthetic embryos.
  • They are starting to assemble stem cells that can organize themselves into embryolike structures.
  • But in the future, they may develop into far more complex forms, the researchers said, such as a beating human heart connected to a rudimentary brain, all created from stem cells
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  • Whatever else, it is sure to unnerve most of us.
  • Scientists, for example, should never create a Sheef that feels pain.
  • Scientists began grappling with the ethics of lab-raised embryos more than four decades ago.
  • In 1979, a federal advisory board recommended that the cutoff should be 14 days.
  • The embryonic cells develop into three types, called germ layers. Each of those germ layers goes on to produce all the body’s tissues and organs.
  • This triggered communication by the cells, and they organized themselves into the arrangement found in an early mouse embryo.
  • Even if ethicists do manage to agree on certain limits, Paul S. Knoepfler, a stem cell biologist at the University of California, Davis, wondered how easy it would be for scientists to know if they had crossed them.
  • Spotting a primitive streak is easy. Determining whether a collection of neurons connected to other tissues in a dish can feel pain is not.
  • dicindioha on 24 Mar 17
     
    Scientists wonder about the response in terms of ethics to their new idea and possibility of synthetic embryos. They might be able to grow into structures that could help in the human body, but to what extent would they stop growing, or would they feel pain? Are we creating life?... just to destroy it?
Emily Horwitz

News from The Associated Press - 0 views

hosted.ap.org/...US_SCI_STEM_CELLS_DEAFNESS

science ethics AP knowledge research stem cells

shared by Emily Horwitz on 13 Sep 12 - No Cached
  • For the first time, scientists have improved hearing in deaf animals by using human embryonic stem cells, an encouraging step for someday treating people with certain hearing disorders.
  • it will be years before human patients might benefit.
  • Human embryonic stem cells can be manipulated to produce any type of cell. Using them is controversial because they are initially obtained by destroying embryos.
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  • Yehoash Raphael of the University of Michigan, who didn't participate in the work, said it's possible the stem cell transplants worked by stimulating the gerbils' own few remaining nerve cells, rather than creating new ones. But either way, "this is a big step forward in use of stem cells for treating deafness," he said.
grayton downing

Opinion: I Want My Kidney | The Scientist Magazine® - 0 views

www.the-scientist.com/?articles.view/articleNo/38154/title/Opinion--I-Want-My-Kidney/

kidney science research

shared by grayton downing on 11 Nov 13 - No Cached
  • Indeed,10 years ago, one of Atala's young patients, Luke Massella, received an engineered bladder made using similar technology.
  • human kidney, albeit non-functional, takes us a step closer to utilizing the enormous potential of stem cells from different sources.
  • disorders can contribute to end-stage renal disease, which is the main indicator for kidney transplantation. Diabetes alone, which is on the rise the world over, is the major cause, responsible for more than 40 percent of all end-stage renal disease cases in need of kidney transplant
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  • Research on differentiated kidney cells, particularly podocytes that can be cultured in the lab, may hold some answers. Although there are a few human- and mouse-derived cell lines that potentially differentiate into functional podocytes, there is a need for better cell lines and systems that mimic the in vivo situation more closely
grayton downing

Genetic Diversity in the Brain | The Scientist Magazine® - 0 views

www.the-scientist.com/?articles.view/articleNo/38095/title/Genetic-Diversity-in-the-Brain/

diversity brain science research brain science

shared by grayton downing on 05 Nov 13 - No Cached
  • Genomic analyses of single human neurons—either from postmortem brains or those derived in culture—reveal a considerable degree of DNA copy number variation, according to a paper
  • likely that these genetic differences affect brain cell function, and they may even shape our personalities, academic abilities, and susceptibilities to neurological diseases.
  • There was a really long-standing hypothesis that given the huge diversity of cell types in the brain, there might be [genetic] mechanisms . . . to generate [the] diversity,” Hall explained.
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  • found similar copy number variations in neurons derived in culture from human induced pluripotent stem cells (iPSCs)
  • neural progenitor cells derived from the same iPSC lines did not exhibit such abundant diversity. This suggested that the genetic variation in neurons occurred only at later stages of differentiation. And that the variation developed in a short space of time—the seven weeks it took to differentiate neurons from neural progenitors. Furthermore, the results implied that genetic variations seen in adult postmortem brains were unlikely to be a mere side effect of aging.
anonymous

Human Brain: facts and information - 0 views

www.nationalgeographic.com/...brain

shared by anonymous on 03 Nov 20 - No Cached
  • The human brain is more complex than any other known structure in the universe.
  • Weighing in at three pounds, on average, this spongy mass of fat and protein is made up of two overarching types of cells—called glia and neurons—and it contains many billions of each.
  • The cerebrum is the largest part of the brain, accounting for 85 percent of the organ's weight. The distinctive, deeply wrinkled outer surface is the cerebral cortex. It's the cerebrum that makes the human brain—and therefore humans—so formidable. Animals such as elephants, dolphins, and whales actually have larger brains, but humans have the most developed cerebrum. It's packed to capacity inside our skulls, with deep folds that cleverly maximize the total surface area of the cortex.
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  • The cerebrum has two halves, or hemispheres, that are further divided into four regions, or lobes. The frontal lobes, located behind the forehead, are involved with speech, thought, learning, emotion, and movement.
  • Behind them are the parietal lobes, which process sensory information such as touch, temperature, and pain.
  • At the rear of the brain are the occipital lobes, dealing with vision
  • Lastly, there are the temporal lobes, near the temples, which are involved with hearing and memory.
  • The second-largest part of the brain is the cerebellum, which sits beneath the back of the cerebrum.
  • diencephalon, located in the core of the brain. A complex of structures roughly the size of an apricot, its two major sections are the thalamus and hypothalamus
  • The brain is extremely sensitive and delicate, and so it requires maximum protection, which is provided by the hard bone of the skull and three tough membranes called meninges.
  • Want more proof that the brain is extraordinary? Look no further than the blood-brain barrier.
  • This led scientists to learn that the brain has an ingenious, protective layer. Called the blood-brain barrier, it’s made up of special, tightly bound cells that together function as a kind of semi-permeable gate throughout most of the organ. It keeps the brain environment safe and stable by preventing some toxins, pathogens, and other harmful substances from entering the brain through the bloodstream, while simultaneously allowing oxygen and vital nutrients to pass through.
  • One in five Americans suffers from some form of neurological damage, a wide-ranging list that includes stroke, epilepsy, and cerebral palsy, as well as dementia.
  • Alzheimer’s disease, which is characterized in part by a gradual progression of short-term memory loss, disorientation, and mood swings, is the most common cause of dementia. It is the sixth leading cause of death in the United States
  • 50 million people suffer from Alzheimer’s or some form of dementia. While there are a handful of drugs available to mitigate Alzheimer’s symptoms, there is no cure.
  • Unfortunately, negative attitudes toward people who suffer from mental illness are widespread. The stigma attached to mental illness can create feelings of shame, embarrassment, and rejection, causing many people to suffer in silence.
  • In the United States, where anxiety disorders are the most common forms of mental illness, only about 40 percent of sufferers receive treatment. Anxiety disorders often stem from abnormalities in the brain’s hippocampus and prefrontal cortex.
  • Attention-deficit/hyperactivity disorder, or ADHD, is a mental health condition that also affects adults but is far more often diagnosed in children.
  • ADHD is characterized by hyperactivity and an inability to stay focused.
  • Depression is another common mental health condition. It is the leading cause of disability worldwide and is often accompanied by anxiety. Depression can be marked by an array of symptoms, including persistent sadness, irritability, and changes in appetite.
  • The good news is that in general, anxiety and depression are highly treatable through various medications—which help the brain use certain chemicals more efficiently—and through forms of therapy
  • anonymous on 03 Nov 20
     
    Here is some anatomy of the brain and descriptions of diseases like Alzheimer's and conditions like ADHD, depression, anxiety.
Emily Horwitz

Scientists Make Progress in Tailor-Made Organs - NYTimes.com - 0 views

www.nytimes.com/...ess-in-tailor-made-organs.html

science biomedical engineering nytimes bioethics stem cells

shared by Emily Horwitz on 14 Nov 12 - No Cached
  • Emily Horwitz on 14 Nov 12
     
    An intriguing article about a more bioethically non-controversial way of reconstructing damaged organs in the body.
oliviaodon

A scientific revolution? - 0 views

www.ncbi.nlm.nih.gov/...PMC1369155

science paradigm shift

shared by oliviaodon on 28 Feb 17 - No Cached
  • Puzzle-solving science, according to Kuhn, can therefore trigger a scientific revolution as scientists struggle to explain these anomalies and develop a novel basic theory to incorporate them into the existing body of knowledge. After an extended period of upheaval, in which followers of the new theory storm the bastions of accepted dogma, the old paradigm is gradually replaced.
  • biology is heading towards a similar scientific revolution that may shatter one of its most central paradigms. The discovery of a few small proteins with anomalous behaviour is about to overcome a central tenet of molecular biology: that information flows unidirectionally from the gene to the protein to the phenotype. It started with the discovery that prions, a class of small proteins that can exist in different forms, cause a range of highly debilitating diseases. This sparked further research
  • Scientific revolutions are still rare in biology, given that the field, unlike astronomy or physics, is relatively young.
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  • The idea that all living beings stem from a primordial cell dating back two billion years is, in my opinion, a true paradigm. It does not have a heuristic value, unlike paradigms in physics such as gravitation or Einstein's famous equation, but it has a fundamental aspect.
Javier E

National - Robert Wright - Creationists vs. Evolutionists: An American Story - The Atla... - 0 views

www.theatlantic.com/...258384

science denial global warming evolution Darwinian US belief

shared by Javier E on 12 Jun 12 - No Cached
  • About half of Americans--46 percent, in the latest Gallup Poll--believe human beings weren't created by evolution. Over at the Daily Dish, Andrew Sullivan says this is a grave problem. "I simply do not know how you construct a civil discourse indispensable to a functioning democracy with this vast a gulf between citizens in their basic understanding of the world." Over at Mother Jones, Kevin Drum says Andrew should calm down. "This 46% number has barely budged over the past three decades
  • in recent years disagreement over evolution has become more politically charged, more acrimonious, and that the rancor may be affecting other science-related policy areas, such as climate change.
  • fundamentalist Christians, upon being maligned by know-it-all Darwinians, are starting to see secular scientists more broadly as the enemy; Darwinians, climate scientists, and stem cell researchers start to seem like a single, menacing blur.
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  • Over the past two years, the portion of respondents who don't believe in evolution has grown by six percentage points. Where did those people come from? The graph suggests they're people who had previously believed in an evolution guided by God--a group whose size dropped by a corresponding six percentage points. It's as if people who had previously seen evolution and religion as compatible were told by the new militant Darwinians, "No, you must choose: Which is it, evolution or religion?"--and pretty much all of them chose religion.
Javier E

How Humans Ended Up With Freakishly Huge Brains | WIRED - 0 views

www.wired.com/...up-with-freakishly-huge-brains

brain science human origins intelligence evolution

shared by Javier E on 29 Nov 15 - No Cached
  • paleontologists documented one of the most dramatic transitions in human evolution. We might call it the Brain Boom. Humans, chimps and bonobos split from their last common ancestor between 6 and 8 million years ago.
  • Starting around 3 million years ago, however, the hominin brain began a massive expansion. By the time our species, Homo sapiens, emerged about 200,000 years ago, the human brain had swelled from about 350 grams to more than 1,300 grams.
  • n that 3-million-year sprint, the human brain almost quadrupled the size its predecessors had attained over the previous 60 million years of primate evolution.
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  • There are plenty of theories, of course, especially regarding why: increasingly complex social networks, a culture built around tool use and collaboration, the challenge of adapting to a mercurial and often harsh climate
  • Although these possibilities are fascinating, they are extremely difficult to test.
  • Although it makes up only 2 percent of body weight, the human brain consumes a whopping 20 percent of the body’s total energy at rest. In contrast, the chimpanzee brain needs only half that.
  • contrary to long-standing assumptions, larger mammalian brains do not always have more neurons, and the ones they do have are not always distributed in the same way.
  • The human brain has 86 billion neurons in all: 69 billion in the cerebellum, a dense lump at the back of the brain that helps orchestrate basic bodily functions and movement; 16 billion in the cerebral cortex, the brain’s thick corona and the seat of our most sophisticated mental talents, such as self-awareness, language, problem solving and abstract thought; and 1 billion in the brain stem and its extensions into the core of the brain
  • In contrast, the elephant brain, which is three times the size of our own, has 251 billion neurons in its cerebellum, which helps manage a giant, versatile trunk, and only 5.6 billion in its cortex
  • primates evolved a way to pack far more neurons into the cerebral cortex than other mammals did
  • The great apes are tiny compared to elephants and whales, yet their cortices are far denser: Orangutans and gorillas have 9 billion cortical neurons, and chimps have 6 billion. Of all the great apes, we have the largest brains, so we come out on top with our 16 billion neurons in the cortex.
  • “What kinds of mutations occurred, and what did they do? We’re starting to get answers and a deeper appreciation for just how complicated this process was.”
  • there was a strong evolutionary pressure to modify the human regulatory regions in a way that sapped energy from muscle and channeled it to the brain.
  • Accounting for body size and weight, the chimps and macaques were twice as strong as the humans. It’s not entirely clear why, but it is possible that our primate cousins get more power out of their muscles than we get out of ours because they feed their muscles more energy. “Compared to other primates, we lost muscle power in favor of sparing energy for our brains,” Bozek said. “It doesn’t mean that our muscles are inherently weaker. We might just have a different metabolism.
  • a pioneering experiment. Not only were they going to identify relevant genetic mutations from our brain’s evolutionary past, they were also going to weave those mutations into the genomes of lab mice and observe the consequences.
  • Silver and Wray introduced the chimpanzee copy of HARE5 into one group of mice and the human edition into a separate group. They then observed how the embryonic mice brains grew.
  • After nine days of development, mice embryos begin to form a cortex, the outer wrinkly layer of the brain associated with the most sophisticated mental talents. On day 10, the human version of HARE5 was much more active in the budding mice brains than the chimp copy, ultimately producing a brain that was 12 percent larger
  • “It wasn’t just a couple mutations and—bam!—you get a bigger brain. As we learn more about the changes between human and chimp brains, we realize there will be lots and lots of genes involved, each contributing a piece to that. The door is now open to get in there and really start understanding. The brain is modified in so many subtle and nonobvious ways.”
  • As recent research on whale and elephant brains makes clear, size is not everything, but it certainly counts for something. The reason we have so many more cortical neurons than our great-ape cousins is not that we have denser brains, but rather that we evolved ways to support brains that are large enough to accommodate all those extra cells.
  • There’s a danger, though, in becoming too enamored with our own big heads. Yes, a large brain packed with neurons is essential to what we consider high intelligence. But it’s not sufficient
  • No matter how large the human brain grew, or how much energy we lavished upon it, it would have been useless without the right body. Three particularly crucial adaptations worked in tandem with our burgeoning brain to dramatically increase our overall intelligence: bipedalism, which freed up our hands for tool making, fire building and hunting; manual dexterity surpassing that of any other animal; and a vocal tract that allowed us to speak and sing.
  • Human intelligence, then, cannot be traced to a single organ, no matter how large; it emerged from a serendipitous confluence of adaptations throughout the body. Despite our ongoing obsession with the size of our noggins, the fact is that our intelligence has always been so much bigger than our brain.
anonymous

The Costly, Painful, Lonely Burden of Care - The New York Times - 0 views

www.nytimes.com/...caregiving-burnout.html

shared by anonymous on 27 Mar 21 - No Cached
  • The Costly, Painful, Lonely Burden of Care
  • Health care in the U.S. relies on an “invisible army” of caregivers — mostly women. For many, stunted careers, lost earnings and exhaustion are part of the fallout.
  • “If society wants us to keep caring for others, it’s going to have to show a little more care for us.”
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  • Her husband, Brad Buchanan, was late for family dinner. She found him in the bathroom, coughing up blood — a lot of it.
  • Doctors found that a tumor had ruptured in one of his lungs and he urgently needed chemo. As her husband became critically ill, Ms. Washington, a freelance writer, was thrust into the role of nurse.
  • “My hands were shaking,” she said as she remembered apprehensively pushing in the drugs for the first time and feeling the weight of keeping her husband alive.
  • Mr. Buchanan had a stem cell transplant that left him with graft-versus-host disease
  • Depending on the analysis, between 61 and 75 percent of caregivers are women
  • When she explained that she had two children who also had needs, he said, “Well, usually family steps in, and it works out fine.”
  • Ms. Washington felt the burden of responsibility, but also the sting
  • The U.S. health care system relies on and takes for granted the “invisible army” of people — mostly women — who keep the system functioning by performing home care for the many people who are “too well for the hospital” but “too sick for home,” as well as for those on end-of-life care.
  • In 2017, AARP found that about 41 million family caregivers in America perform roughly $470 billion worth of unpaid labor a year.
  • they tend to do more personal care tasks like helping patients bathe and use the toilet than their male counterparts, who are more likely to oversee finances and arrangement of care.
  • The historical roots are complex, but as Evelyn Glenn puts it in “Forced to Care,”
  • emale caregivers put in more hours — 22 to men’s 17
  • they are also more likely to stand by their partner through a serious illness
  • Many people who take on caregiving roles experience negative health impacts, but women are especially at risk of the fallout from caregiver stress.
  • Female caregivers are also 2.5 times more likely to live in poverty as non-caregiver
  • A 2011 study found that women who left their jobs to care for a parent lost an average of $324,000 in wages and benefits over their lifetimes.
  • Ms. Washington was able to dip into savings and a recent inheritance to help pay for supplemental in-home care, but it was still a struggle, causing stress, resentment and lost income.
  • It was hard to have my life put on hold. Everything kind of slipped away.
  • I lost a sense of who I was. I was going to pick up a prescription for myself, the only prescription I had when my husband was sick, and the pharmacist asked for my date of birth, and I gave his date of birth
  • People talk about how it’s the most important job in the world, taking care of our children or taking care of our vulnerable elders, and yet those are some of the worst paid jobs.
  • How much is a quarterback paid versus someone who is doing care for a vulnerable elderly person?
  • How did care work become so undervalued?
  • A doctor told Ms. Washington that her husband would need 24-hour care and “could not be left alone for even a moment.”
  • Western culture has long framed care work done by women as a moral duty or obligation, rather than an economic activity.
  • If your earnings are lower than they would normally be because you’re busy caring for a family member, and you can’t save and pay into social security, it can lock whole families into a cycle of lower wealth and economic instability.
  • And what should someone not do
  • Don’t tell someone to stay positive. For me, there was no staying about it, because I didn’t feel positive to start with. It brought up this feeling
  • My time isn’t my own, but surely my emotions can be
tonycheng6

Anti-ageing effects of protein restriction unpacked - 0 views

www.nature.com/...d41586-020-03662-x

shared by tonycheng6 on 15 Jan 21 - No Cached
  • The idea that dietary restriction can be used as a tool to increase lifespan has been a centrepiece of ageing research for decades. But the mechanisms by which dietary restriction might act, and the specific nutritional components involved, remain unclear.
  • Both dietary protein restriction (which results in low levels of leucine and other BCAAs) and inhibition of mTOR can extend lifespan in animals
  • Flies that carry a mutation in this residue have lower mTOR activity than do controls. They are also longer-lived, and are protected against the negative lifespan-shortening effects of a high-protein diet.
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  • In contrast to a previous study6, they observed a robust lifespan extension in male mice fed a BCAA-restricted diet throughout life, equal to the benefits of dietary protein restriction.
  • Interestingly, female mice showed no lifespan extension from BCAA or dietary protein restriction, and if BCAA restriction was started during middle age, the benefits on males were greatly reduced. Thus, both studies collectively point to mTOR as a primary mediator of the benefits associated with BCAA restriction (Fig. 1).
  • A clear picture is emerging of how specific amino acids are sensed by sestrin to regulate mTOR signalling and autophagy and so preserve the function of intestinal stem cells during ageing.
  • Genetic background is crucial in the response to dietary restriction, with an identical low-calorie regimen increasing lifespan in some mouse strains but shortening it in others
  • There is also evidence that dietary restriction initiated later in life might have reduced benefits in rodents and, in some cases, result in premature death
  • Taken together, these observations suggest that although protein- and BCAA-restricted diets are a powerful research tool for exploring the fundamental mechanisms of ageing, it is premature to recommend adoption by the general population.
lucieperloff

Don't Waste Your Emotions on Plants, They Have No Feelings | Live Science - 0 views

www.livescience.com/plants-dont-think-or-feel.html

Consciousness research science

shared by lucieperloff on 03 Nov 20 - No Cached
  • Trees — and all plants, for that matter — feel nothing at all, because consciousness, emotions and cognition are hallmarks of animals alone, scientists recently reported in an opinion article.
  • Though plants lack brains, the firing of electrical signals in their stems and leaves nonetheless triggered responses that hinted at consciousness, researchers previously reported.
  • Beginning in 2006, some scientists have argued that plants possess neuron-like cells that interact with hormones and neurotransmitters, forming "a plant nervous system, analogous to that in animals
    • lucieperloff
      lucieperloff on 03 Nov 20
       
      so what changed?
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  • "If the lower animals — which have nervous systems — lack consciousness, the chances that plants without nervous systems have consciousness are effectively nil," Taiz said.
  • "Being unconscious is in all likelihood an advantage to plants and contributes to their evolutionary fitness," he added.
manhefnawi

How the Brain Deletes Old Memories | Science | AAAS - 0 views

www.sciencemag.org/...how-brain-deletes-old-memories

Memory Science Brain

shared by manhefnawi on 12 Jun 18 - No Cached
  • Although the precise role of neurogenesis in memory is still controversial, more than a decade of research has demonstrated that boosting neurogenesis with exercise and antidepressants such as Prozac can increase rodents' ability to learn new information about places and events. A few years ago, however, neuroscientist Paul Frankland of the Hospital for Sick Children in Toronto, Canada, noticed that some of the animals in his experiment actually did worse on certain memory tasks when their neuron birth rates had been ramped up. In particular, they performed poorly on tests that required them to retain details about past events.
  • It is difficult to completely eliminate the birth of new neurons in infant mice, but by genetically engineering dividing neural stem cells to self-destruct the team was able to achieve about a 50% reduction of neurogenesis in the animals, Frankland says. With less neurogenesis, the young rodents acted more like adult mice in the experiment. They froze when first placed in the box for roughly a week, rather than just 1 day, after receiving the foot shocks.
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