Skip to main content

Home/ TOK Friends/ Group items matching "cells" in title, tags, annotations or url

Group items matching
in title, tags, annotations or url

Sort By: Relevance | Date Filter: All | Bookmarks | Topics Simple Middle
6More

Evolving Pain Resistance | The Scientist Magazine® - 1 views

  • Grasshopper mice of the southwestern US deserts (Onychomys torridus) have evolved to take advantage of a normally well-protected food source:
  • “The grasshopper mouse has found a way, very cleverly, to disconnect the pain pathway
  • results suggested that rather than blocking the binding of the venom altogether, the grasshopper mouse had evolved a strategy to block the transmission of pain when the venom was bound. Sure enough, when the team pre-treated the mice with venom, and then administered a painful formalin stimulus, the mice were protected from the pain.
  • ...3 more annotations...
  • that are found on pain-transmitting neurons called nociceptors.
  • further investigate how the scorpion venom inhibits the transmission of pain, Rowe and her colleagues sequenced the Nav1.8 channel, replaced grasshopper mouse sequences with house mouse sequences, and expressed the mutant channels in a cell line to observe the effects of the genetic changes.
  • “a really small amount of variation—one amino acid—can actually produce these really profound physiological effects,” Rowe said. “Evolutionarily speaking, it allows this mouse to then feed on a chemically protected scorpion.”
4More

Scientists are Growing Tiny Cerebral Cortexes in Petri Dishes - 0 views

  • researchers have perfected a technique for growing miniature balls of cortical tissue—the key working tissue in the human brain—in a dish
  • As off-the-wall insane as this sounds, it isn’t just some mad science experiment. These tiny, 3D structures function much like the outer mantle, or cortex, of the brain of the person from which they were derived.
  • “While the technology is still maturing, there is great potential for using these assays to more accurately develop, test safety and effectiveness of new treatments before they are used in individuals with a mental illness,”
  • ...1 more annotation...
  • ” These tiny balls of brain tissue include neurons supported by a cortex-like network of glial cells.
5More

Amnesia researchers use light to restore 'lost' memories in mice | Science | The Guardian - 0 views

  • Amnesia remains a controversial subject in the field of neuroscience, with some researchers arguing that it occurs when cells are damaged and memory cannot be stored, while others believe that the memories are simply blocked and cannot be recalled.
  • The study, published in the US journal Science, indicated that memories do in fact remain, but are simply unable to be recollected.
  • The study allowed scientists to separate memory storage mechanisms from those allowing an organism to form and recover the memory, said MIT researcher Tomas Ryan, who co-authored the study.
  • ...2 more annotations...
  • “The strengthening of engram synapses is crucial for the brain’s ability to access or retrieve those specific memories,” Ryan said.
  • “past memories may not be erased, but could simply be lost and inaccessible for recall”.
16More

How Many of Your Memories Are Fake? - The Atlantic - 3 views

  • Special K for breakfast. Liverwurst and cheese for lunch. And I remember the song ‘You've Got Personality’ was playing as on the radio as I pulled up for work,” said Healy, one of 50 confirmed people in the United States with Highly Superior Autobiographical Memory, an uncanny ability to remember dates and events.
  • New research released this week has found that even people with phenomenal memory are susceptible to having “false memories,” suggesting that “memory distortions are basic and widespread in humans, and it may be unlikely that anyone is immune,” according to the authors of the study published in Proceedings of the National Academy of Sciences (PNAS).
  • Professor Elizabeth Loftus, who has spent decades researching how memories can become contaminated with people remembering—sometimes quite vividly and confidently—events that never happened. Loftus has found that memories can be planted in someone’s mind if they are exposed to misinformation after an event, or if they are asked suggestive questions about the past
  • ...12 more annotations...
  • Loftus’s research has already rattled our justice system, which relies so heavily on eyewitness testimonies.
  • “It’s so powerful when somebody tells you something and they have a lot of detail,” Loftus said. “Especially when they express emotion. To just say, ‘Oh my god it must be true.’ But all those characteristics are also true of false memories, particularly the heavily rehearsed ones that you ruminate over. They can be very detailed. You can be confident. You can be emotional. So you need independent corroboration.”
  • When later asked about the events, the superior memory subjects indicated the erroneous facts as truth at about the same rate as people with normal memory.
  • been able to successfully convince ordinary people that they were lost in a mall in their childhood, pointed out that false memory recollections also occur among high profile people.
  • All memory, as McGaugh explained, is colored with bits of life experiences. When people recall, “they are reconstructing,” he said. “It doesn't mean it’s totally false. It means that they’re telling a story about themselves and they’re integrating things they really do remember in detail, with things that are generally true.”
  • “puzzling why (Highly Superior Autobiographical Memory) individuals remember some trivial details, such as what they had for lunch 10 years ago, but not others, such as words on a word list or photographs in a slideshow,” Patihis and colleagues noted in the PNAS study. “The answer to this may be that they may extract some personally relevant meaning from only some trivial details and weave them into the narrative for a given day.”
  • For all of us, the stronger the emotion attached to a moment, the more likely those parts of our brains involved in memory will become activated.
  • “Why did evolution do that?” McGaugh said. “Because it was essential for our survival.
  • We now know animals are likely susceptible to memory distortions too, as MIT researchers recently were able to successfully plant false memories in mice.
  • “We’re all creating stories. Our lives are stories in that sense.”
  • “but you as the writer have the obligation to get as close to the truth as you possibly can,” Meyer said
  • The mind and its memory do not just record and retrieve information and experiences, but also infer, fill in gaps, and construct, wrote Bryan Boyd wrote in On the Origin of Stories. “Episodic memory’s failure to provide exact replicas of experiences appears to not be a limitation of memory but an adaptive design.”
  •  
    This is an interesting article about the fallacy of memory, and our perceptions of our memory.
1More

HIV drugs should be given at diagnosis, trial suggests - BBC News - 0 views

  •  
    HIV drugs should be given at the moment of diagnosis, according to a major trial that could change the way millions of people are treated. People currently get antiretroviral therapy only when their white blood cell levels drop. But a US-led study has now been cut short as early treatment was so beneficial for patients.
9More

Lab-Grown Model Brains | The Scientist Magazine® - 0 views

  • In an Austrian laboratory, a team of scientists has grown three-dimensional models of embryonic human brain
  • “Even the most complex organ—the human brain—can start to form without any micro-manipulation.”
  • Knoblich cautioned that the organoids are not “brains-in-a-jar.” “We’re talking about the very first steps of embryonic brain development, like in the first nine weeks of pregnancy,” he said. “They’re nowhere near an adult human brain and they don’t form anything that resembles a neuronal network.”
  • ...6 more annotations...
  • It took a huge amount of work to fine-tune the conditions, but once the team did, the organoids grew successfully within just 20 to 30 days.
  • scientists have developed organoids that mimic several human organs, including eyes, kidneys, intestines, and even brains.
  • They really highlight the ability just nudge these human embryonic cells and allow them to self-assemble
  • The mouse brain isn’t good enough for studying microcephaly,” said Huttner. “You need to put those genes into an adequate model like this one. It is, after all, human. It definitely enriches the field. There’s no doubt about that.”
  • organoids are unlikely to replace animal experiments entirely. “We can’t duplicate the elegance with which one can do genetics in animal models,” he said, “but we might be able to reduce the number of animal experiments, especially when it comes to toxicology or drug testing.”
  • the future, he hopes to develop larger organoids.
6More

Bird Flu Mutation Risk | The Scientist Magazine® - 0 views

  • some strains of both viruses are just one mutation away from getting a better grip on the cells in our upper airways. If wild viruses accrue those mutations, they may find it far easier to spread from infected to uninfected people, increasing the risk of a pandemic.
  • “These viruses are rapidly evolving and our stockpiles of vaccine are largely based on outdated strains,” he said. “We hope that our discoveries will help us to stay ahead of the curve by ensuring that vaccines are stockpiled against strains that are closest to adapting to humans.”
  • rather than focusing on these previously identified mutations, the team took a new approach. They modeled the way HA interacts with different glycans, and identified four structural features that bestow the protein with a preference for human receptors over bird ones.
  • ...3 more annotations...
  • they analyzed the diversity of existing H5N1 strains and found that many wild viruses are already tantalizingly close to becoming potentially contagious among humans.
  • we know very little about the actual receptors in human airways that are relevant for flu viruses.” Even the so-called “human” receptors can vary significantly, and it’s unclear which ones are found in different parts of the airways, or how common they are.
  • identified should be tested in ferret experiments to see if they genuinely are more efficient at spreading between mammals. However, given the controversy surrounding the development of potentially contagious flu strains, Fouchier wonders “whether we would be allowed to empirically test this newly acquired knowledge in animal models.”
8More

Many Psychology Findings Not as Strong as Claimed, Study Says - The New York Times - 1 views

  • a painstaking yearslong effort to reproduce 100 studies published in three leading psychology journals has found that more than half of the findings did not hold up when retested. The analysis was done by research psychologists, many of whom volunteered their time to double-check what they considered important work. Their conclusions, reported Thursday in the journal Science, have confirmed the worst fears of scientists who have long worried that the field needed a strong correction.
  • The vetted studies were considered part of the core knowledge by which scientists understand the dynamics of personality, relationships, learning and memory. Therapists and educators rely on such findings to help guide decisions, and the fact that so many of the studies were called into question could sow doubt in the scientific underpinnings of their work.
  • The new analysis, called the Reproducibility Project, found no evidence of fraud or that any original study was definitively false. Rather, it concluded that the evidence for most published findings was not nearly as strong as originally claimed.
  • ...5 more annotations...
  • r. John Ioannidis, a director of Stanford University’s Meta-Research Innovation Center, who once estimated that about half of published results across medicine were inflated or wrong, noted the proportion in psychology was even larger than he had thought.
  • He said the problem could be even worse in other fields, including cell biology, economics, neuroscience, clinical medicine, and animal research.
  • The act of double-checking another scientist’s work has been divisive. Many senior researchers resent the idea that an outsider, typically a younger scientist, with less expertise, would critique work that often has taken years of study to pull off.
  • The overall “effect size,” a measure of the strength of a finding, dropped by about half across all of the studies. Yet very few of the redone studies contradicted the original ones; their results were simply weaker.
  • The project’s authors write that despite the painstaking effort to duplicate the original research, there could be differences in the design or context of the reproduced work that account for the different findings. Many of the original authors certainly agree.
1More

Quarter of skin cells 'on road to cancer' - BBC News - 0 views

  •  
    More than a quarter of a middle-aged person's skin may have already made the first steps towards cancer, a study suggests. Analysis of samples from 55- to 73-year-olds found more than 100 DNA mutations linked to cancer in every 1 sq cm (0.1 sq in) of skin.
3More

Toddlers Have Sense of Justice, Puppet Study Shows - The New York Times - 0 views

  • Children as young as age 3 will intervene on behalf of a victim, reacting as if victimized themselves, scientists have found.
  • In one experiment, when one puppet took toys or cookies from another puppet, children responded by pulling a string that locked the objects in an inaccessible cave. When puppets took objects directly from the children themselves, they responded in the same way.“The children treated these two violations equally,”
  • “Their sense of justice is victim-focused rather than perpetrator focused,” Dr. Jensen said. “The take-home message is that preschool children are sensitive to harm to others, and given a choice would rather restore things to help the victim than punish the perpetrator.”
8More

Don't leave learning to the young. Older brains can grow, too. - NYTimes.com - 0 views

  • Geerat Vermeij, a biologist at the University of California-Davis who has been blind since the age of 3, has identified many new species of mollusks based on tiny variations in the contours of their shells. He uses a sort of spatial or tactile giftedness that is beyond what any sighted person is likely to have.
  • The writer Ved Mehta, also blind since early childhood, navigates in large part by using “facial vision” — the ability to sense objects by the way they reflect sounds, or subtly shift the air currents that reach his face.
  • Ben Underwood, a remarkable boy who lost his sight at 3 and died at 16 in 2009, developed an effective, dolphin-like strategy of emitting regular clicks with his mouth and reading the resulting echoes from nearby objects. He was so skilled at this that he could ride a bike and play sports and even video games.
  • ...5 more annotations...
  • To what extent are we shaped by, and to what degree do we shape, our own brains? And can the brain’s ability to change be harnessed to give us greater cognitive powers? The experiences of many people suggest that it can.
  • This growth can even happen within a matter of days.
  • Every time we practice an old skill or learn a new one, existing neural connections are strengthened and, over time, neurons create more connections to other neurons. Even new nerve cells can be generated.
  • Music is an especially powerful shaping force, for listening to and especially playing it engages many different areas of the brain
  • Whether it is by learning a new language, traveling to a new place, developing a passion for beekeeping or simply thinking about an old problem in a new way, all of us can find ways to stimulate our brains to grow
7More

This is what your brain looks like on magic mushrooms (Wired UK) - 0 views

  • In recent years, a focus on brain structures and regions has given way to an emphasis on neurological networks: how cells and regions interact, with consciousness shaped not by any given set of brain regions, but by their interplay.
  • Understanding the networks, however, is no easy task
  • In mathematical terms, said Petri, normal brains have a well-ordered correlation state. There's not much cross-linking between networks. That changes after the psilocybin dose. Suddenly the networks are cross-linking like crazy, but not in random ways. New types of order emerge.
  • ...4 more annotations...
  • Perhaps some aspects of consciousness arise from these meta-networks -- and to investigate the proposition, the researchers analysed fMRI scans of 15 people after being injected with psilocybin, the active ingredient in magic mushrooms, and compared them to scans of their brain activity after receiving a placebo.
  • "One possible by-product of this greater communication across the whole brain is the phenomenon of synaesthesia" -- the experience, common during psychedelic experiences, of sensory mix-up: tasting colours, feeling sounds, seeing smells, and so on.
  • A truer way of visualising it, he said, would be in three dimensions, with connections between networks forming a sponge-like topography.
  • "The big question in neuroscience is where consciousness comes from," Petri said. For now, he said, "We don't know."
11More

New Truths That Only One Can See - NYTimes.com - 1 views

  • Replication, the ability of another lab to reproduce a finding, is the gold standard of science, reassurance that you have discovered something true. But that is getting harder all the time.
  • With the most accessible truths already discovered, what remains are often subtle effects, some so delicate that they can be conjured up only under ideal circumstances, using highly specialized techniques.
  • Taking into account the human tendency to see what we want to see, unconscious bias is inevitable.
  • ...8 more annotations...
  • He and his colleagues could not replicate 47 of 53 landmark papers about cancer. Some of the results could not be reproduced even with the help of the original scientists working in their own labs.
  • Paradoxically the hottest fields, with the most people pursuing the same questions, are most prone to error, Dr. Ioannidis argued. If one of five competing labs is alone in finding an effect, that result is the one likely to be published. But there is a four in five chance that it is wrong. Papers reporting negative conclusions are more easily ignored.
  • The effect is amplified by competition for a shrinking pool of grant money and also by the design of so many experiments — with small sample sizes (cells in a lab dish or people in an epidemiological pool) and weak standards for what passes as statistically significant. That makes it all the easier to fool oneself.
  • The fear that much published research is tainted has led to proposals to make replication easier by providing more detailed documentation, including videos of difficult procedures.
  • A call for the establishment of independent agencies to replicate experiments has led to a backlash, a fear that perfectly good results will be thrown out.
  • Scientists talk about “tacit knowledge,” the years of mastery it can take to perform a technique. The image they convey is of an experiment as unique as a Rembrandt.
  • Embedded in the tacit knowledge may be barely perceptible tweaks and jostles — ways of unknowingly smuggling one’s expectations into the results, like a message coaxed from a Ouija board.
  • Exciting new results will continue to appear. But as the quarry becomes more elusive, the trophies are bound to be fewer and fewer.
2More

WATCH: Protester Confronts Fox Station That Deceptively Edited 'Kill A Cop' Chant - 0 views

  • to murder police on Monday. The chant went "we won't stop, we can't stop, 'til killer cops, are in cell blocks," according to C-SPAN footage. But WBFF cut the audio short and told viewers that the words were in fact "we won't stop, we can't stop, so kill a cop."
  • Jones called out the station several times for misrepresenting her words. "The interesting part that really gets to me is, where you guys edited it and stopped — like, how could that be a mistake?" she said. "Once you play that whole thing, you would know that's not something that's being said," she added. The interviewer apologized several times, and though Jones told the station she was grateful to come on, she also said she now fears for her reputation and her safety. Near the end of the interview she began to cry. "At the end of the day, people's lives are on the line," she said. "Now, even though we're doing this, I still don't feel safe because I still feel like the message is out there." "What if a crazed-out cop or a crazed-out supporter thinks I'm trying to get cops killed?" she later said, wiping tears from her face.
10More

YaleNews | Yale researchers map 'switches' that shaped the evolution of the human brain - 0 views

  • Thousands of genetic “dimmer” switches, regions of DNA known as regulatory elements, were turned up high during human evolution in the developing cerebral cortex, according to new research from the Yale School of Medicine.
  • these switches show increased activity in humans, where they may drive the expression of genes in the cerebral cortex, the region of the brain that is involved in conscious thought and language. This difference may explain why the structure and function of that part of the brain is so unique in humans compared to other mammals.
  • Noonan and his colleagues pinpointed several biological processes potentially guided by these regulatory elements that are crucial to human brain development.
  • ...7 more annotations...
  • “Building a more complex cortex likely involves several things: making more cells, modifying the functions of cortical areas, and changing the connections neurons make with each other
  • Scientists have become adept at comparing the genomes of different species to identify the DNA sequence changes that underlie those differences. But many human genes are very similar to those of other primates, which suggests that changes in the way genes are regulated — in addition to changes in the genes themselves — is what sets human biology apart.
  • First, Noonan and his colleagues mapped active regulatory elements in the human genome during the first 12 weeks of cortical development by searching for specific biochemical, or “epigenetic” modifications
  • same in the developing brains of rhesus monkeys and mice, then compared the three maps to identify those elements that showed greater activity in the developing human brain.
  • wanted to know the biological impact of those regulatory changes.
  • They used those data to identify groups of genes that showed coordinated expression in the cerebral cortex.
  • “While we often think of the human brain as a highly innovative structure, it’s been surprising that so many of these regulatory elements seem to play a role in ancient processes important for building the cortex in all mammals, said first author Steven Reilly
6More

Laser-Controlled And See-Through Brains Get Biomedical Prize | Popular Science - 0 views

  • The mouse brain above has undergone a process called CLARITY
  • Through a series of chemical reactions, CLARITY stabilizes organs taken from an animal or human and makes them transparent to the naked eye.
  • allows scientists to look into organs in a whole new way.
  • ...3 more annotations...
  • The rodent at the top of this story is being studied with a technique called optogenetics, which Deisseroth pioneered.
  • genetically engineered the mouse so that its brain cells turn certain genes on or off when scientists shine laser light onto them. The light enters the mouse's brain through that optical fiber you see in the photo.
  • For example, say 20 percent of people with autism don't have Gene A, but scientists aren't sure what Gene A does. They could turn off Gene A in a mouse's brain and see what happens next. The mouse's reaction could provide a clue about what Gene A does in people and why it's missing in certain patients
5More

Scientists able to 'reverse' emotions associated with memories | Al Jazeera America - 0 views

  • Erasing the anguish associated with a breakup or a traumatic event may soon no longer be confined to the realm of science fiction, or the central idea of the film “Eternal Sunshine of the Spotless Mind,” following an apparent breakthrough by scientists at the Massachusetts Institute of Technology.
  • Neuroscientists at MIT have honed in on the pathway of brain cells that appear to control the way our memories become linked to emotions — and have been able to “reverse” the emotion in mice linked to a specific memory, turning bad memories into good and vice versa
  • "Recalling a memory is not like playing a tape recorder," said Susumu Tonegawa, an MIT neuroscientist and a lead author of the study. "It's a creative process."
  • ...1 more annotation...
  • In the future, one may be able to develop methods that help people to remember positive memories more strongly than negative ones," said Tonegawa.
  •  
    Relates to our unit about emotions and also relates to our memory unit. Discusses how maybe in the future we may be able to develop a way to remember more positive memories rather than negative
6More

The Economist explains: How teenage brains are different | The Economist - 0 views

  • is there such a thing as a “teenage brain”, and does it help to explain the high rates of recklessness among teenagers?
  • the brain blooms with neural connections until a child reaches the age of 11 or 12, and then it selectively prunes away the underused ones, or “grey matter”, throughout adolescence. As the brain grows more streamlined, it becomes better at processing information.
  • The remaining connections are then made more efficient by a process called myelination, which essentially insulates neuronal axons with a sheath of fatty cell material, or “white matter”. The process of replacing grey matter with white matter does not reach the prefrontal cortex until people are in their early 20s. Studies show a relationship between increased myelination and an improved ability to make decisions and control impulses.
  • ...3 more annotations...
  • But although it is always tempting to use hard science to explain otherwise perplexing behaviour, neuroimaging research is still in its infancy
  • There is much about the brain that no one understands yet, and there is rarely a clear relationship between a particular brain region and a discrete function, so any links between brain structure and behaviour remain speculative. Indeed, while researchers often take care to show that the relationship between how a brain looks and how someone behaves is correlative, often this link is misinterpreted as a sign of causation
  • Scientists also point out that brain science cannot be understood in a vacuum. All behaviour is a function of many influences, including parenting, socioeconomic status, nutrition, culture and so on
1More

Fighting cancer and Ebola with nanoparticles - CNN.com - 0 views

  •  
    From targeted remedies such as monoclonal antibodies to surgery, cancer has still managed to elude a treatment that discretely and separately attacks it alone. Nanotechnologies, however - the manipulation of matter at a molecular and even atomic scale to penetrate living cells -- are holding out the promise of opening a new front against deadly conditions from cancer to Ebola.
3More

Our Brains Remember the Good Stuff - The New York Times - 1 views

  • Our Brains Remember the Good Stuff
  • The human brain is attracted to things that were once pleasing even if they no longer are
  • There was no reward, and color was irrelevant.
« First ‹ Previous 121 - 140 of 181 Next › Last »
Showing 20 items per page