Kelly Crowe · CBC News · Last fall, a dangerous animal sickness — chronic wasting disease (CWD) — was detected in a Quebec deer farm. It was a disturbing development — the first sign of this highly contagious infection outside of Alberta and Saskatchewan. There were almost 3,000 deer in the herd. Eleven tested positive for CWD. The rest — more than 2,700 animals — tested negative and were released into the food chain. It was a controversial decision, in part, because so little is known about the human health risk from CWD. The Canadian Food Inspection Agency's website cautions that: "A negative test result does not guarantee that an individual animal is not infected with CWD." "There is not currently a food safety test available for any prion disease," CFIA's spokesperson told CBC News in an email. "The tests that are used are the best available. In accordance with Health Canada's precautionary approach, no animals known to be infected were released into the human food chain." CWD is similar to another frightening animal illness — mad cow disease, officially called "bovine spongiform encephalopathy" or BSE. It is a fatal infection in cattle that can be spread to humans through beef consumption. Both CWD and BSE are caused by a strange protein — a prion — which can jump the species barrier, triggering a deadly cascade of neurological damage. Worldwide, BSE has caused about 225 cases of human prion disease called "variant Creutzfeldt Jacob Disease (vCJD)." There is no treatment and no cure. After an epidemic of mad cow disease in the U.K. more than two decades ago, governments developed strict controls to prevent BSE-infected cattle from being processed for human food. But so far there are few official controls in place to keep CWD out of the food chain.

Keyword: Prions
Link ID: 26349 - Posted: 06.24.2019

By Kevin Arceneaux, Bert N. Bakker, Claire Gothreau, and Gijs Schumacher Science is supposed to be self-correcting. Ugly facts kill beautiful theories, to paraphrase the 19th-century biologist Thomas Huxley. But, as we learned recently, policies at the top scientific journals don’t make this easy. Our story starts in 2008, when a group of researchers published an article (here it is without a paywall) that found political conservatives have stronger physiological reactions to threatening images than liberals do. The article was published in Science, which is one of the most prestigious general science journals around. It’s the kind of journal that can make a career in academia. It was a path-breaking and provocative study. For decades, political scientists and psychologists have tried to understand the psychological roots of ideological differences. The piece published in Science offered some clues as to why liberals and conservatives differ in their worldviews. Perhaps it has to do with how the brain is wired, the researchers suggested—specifically, perhaps it’s because conservatives’ brains are more attuned to threats than liberals’. It was an exciting finding, it helped usher in a new wave of psychophysiological work in the study of politics, and it generated extensive coverage in popular media. In 2018, 10 years after the publication of the study, the findings were featured on an episode of NPR’s Hidden Brain podcast. Fast forward to 2014. All four of us were studying the physiological basis of political attitudes, two of us in Amsterdam, the Netherlands (Bakker and Schumacher at the University of Amsterdam), and two of us in Philadelphia (Arceneaux and Gothreau at Temple University). We had raised funds to create labs with expensive equipment for measuring physiological reactions, because we were excited by the possibilities that the 2008 research opened for us. © 2019 The Slate Group LLC.

Keyword: Emotions
Link ID: 26348 - Posted: 06.24.2019

By Katie Thomas The Food and Drug Administration has approved a new drug to treat low sexual drive in women, the only one besides Addyi, which entered the market in 2015. The drug, to be called Vyleesi, will be sold by AMAG Pharmaceuticals and is intended to be used 45 minutes before sex, via an auto-injector pen that is administered in the thigh or abdomen. “We’re obviously thrilled about being able to bring another option to patients,” said Dr. Julie Krop, the chief medical officer of AMAG, which is based in Waltham, Mass. “These women have suffered significantly, pretty much in silence, for a stigmatized condition, and many of them have not known that it’s a treatable medical condition.” For years, the F.D.A. has been under pressure to encourage more treatments for women with low sexual drive — a condition known as hypoactive sexual desire disorder. Medications for men experiencing erectile dysfunction arrived on the market two decades ago. But these treatments for women have provoked controversy. The first product, Addyi, was approved amid an industry-backed publicity campaign painting detractors as sexist. But some opponents argued its risks outweighed its benefits. Addyi must be taken every day and cannot be taken with alcohol, which can cause fainting. Soon after it went on sale, Addyi was acquired by Valeant Pharmaceuticals for $1 billion, which then failed to promote it. Valeant sold it back to its original owners in 2017 and the drug’s sales have been tepid. Company officials declined to say how much Vyleesi would cost and said they would provide more details when the product goes on sale later this year. They said they expected insurance to cover Vyleesi on a scale similar to Addyi and to male erectile dysfunction drugs — coverage of those drugs by commercial health care plans is mixed. © 2019 The New York Times Company

Keyword: Sexual Behavior
Link ID: 26347 - Posted: 06.22.2019

Brian Mann On a warm early summer day, Bella Doolittle sits on the doorstep of her house feeding biscuits to her dog Pepper. Bella was in her mid-50s when she was diagnosed with Alzheimer's. That was two years ago and the symptoms are advancing, with more memory loss and a new painful anxiety. "Have you ever watched a really terrible horror movie where you know any moment now someone's going to get torn to pieces in a very evil, painful way?" she says, describing the tension she often feels. These are the struggles and setbacks that Bella and Will Doolittle, her husband, talk about in their podcast, the Alzheimer's Chronicles. They say they decided to share their experiences because they know many couples and families are struggling with the same challenges. In all, more than 16 million Americans provide unpaid care for someone living with Alzheimer's or another form of dementia. On a recent episode, Bella and Will described how their life is getting harder, bit by bit. "It definitely has been a very tough period," she recounted. "I became almost suicidal. It was horrible." "Yeah, you were in bad shape," Will said. Anxiety medication is helping, but at times their podcasts are raw, vulnerable and intimate, recorded over their kitchen table. During each episode, they pull back the curtain on aspects of Bella's illness, but they've also been increasingly open about the inner workings of their two-decade long marriage. © 2019 npr

Keyword: Alzheimers
Link ID: 26346 - Posted: 06.22.2019

Laura Sanders When animals are together, their brain activity aligns. These simpatico signals, described in bats and mice, bring scientists closer to understanding brains as they normally exist — enmeshed in complex social situations. Researchers know that neural synchrony emerges in people who are talking, taking a class together and even watching the same movie. But scientists tend to study human brains in highly constrained scenarios, in part because it’s technologically difficult to capture brain activity as people experience rich social interactions (SN: 5/11/19, p. 4). Now two studies published June 20 in Cell offer more details about how synced brains might influence social behavior. In one study, researchers monitored a pair of Egyptian fruit bats in a dark chamber for more than an hour. Neural implants recorded brain activity as the bats groomed themselves, fought, rested and performed other behaviors. The brain activity of the two bats was highly coordinated. When one bat’s neural activity oscillated in a fast rhythm, for example, the other bat’s brain was likely to do the same thing. This coordination continued even when the bats weren’t directly interacting with each other, the team found. But when the bats were separated into two chambers in the same room, this correlated activity fell away, suggesting that the bats had to be sharing the same social context for their brains to link up. |© Society for Science & the Public 2000 - 2019.

Keyword: Animal Communication; Language
Link ID: 26345 - Posted: 06.22.2019

Nicola Davis Changes in the brain that can be spotted years before physical symptoms of Parkinson’s disease occur might act as an early warning sign for the condition, researchers say. It is thought that about 145,000 people in the UK are living with Parkinson’s disease, a neurological condition that can lead to mobility problems, including slowness and tremors, as well as other symptoms such as memory difficulties. There are treatments to help manage symptoms but as yet the disease cannot be slowed or cured. The researchers, based at King’s College London, say the latest findings could eventually lead to new ways to identify people who might go on to develop Parkinson’s; the discoveries could also confirm diagnoses, monitor the disease progression, and aid the development and testing of drugs. Those developments could be some way off though, some scientists have said. Most of the time Parkinson’s appears to have no known cause, so people affected by the disease are not studied before their symptoms appear. But the King’s College studies concerned with genetic mutations making the development of Parkinson’s disease more likely, could point to the warning signs. Marios Politis, a professor and lead author of the research, said: “If you carry the gene [SNCA] it means it is almost certain you are going to develop Parkinson’s in the course of your life.” © 2019 Guardian News & Media Limited

Keyword: Parkinsons; Brain imaging
Link ID: 26344 - Posted: 06.20.2019

By Megan Schmidt Have you ever spaced out during a meeting, but been jolted back to reality by the sound of your boss calling your name a few times? If you’ve ever been in this awkward situation, you might have experienced “microsleep.” This weird state of consciousness is characterized by brief bursts of sleep that happen while a person is awake — often while their eyes are open and they’re either sitting upright, or even performing a task. During microsleep, parts of the brain go offline for a few seconds while the rest of the brain stays awake. It’s sort of like being a zombie for a few brief moments — sans the whole “eating human flesh” part. And usually, people don’t realize it’s happening to them. Researchers don’t fully understand why certain parts of our brain switch off throughout the day. But they have found the states of sleep and wakefulness aren’t as cut and dry as we might assume. And although fatigue does seem to prime the brain for microsleep, even well-rested people do it — a lot. In an experiment published in 2012, participants who got a good night’s sleep played what may be the world’s most boring computer game — tracking a moving target on a monitor with a joystick. During the 50-minute test, researchers monitored people’s brain and eye activity. They found that people’s brains really liked sneaking in microsleep during the humdrum computer game. On average, game players experienced a whopping 79 episodes of microsleep in just under an hour, lasting up to six seconds each time.

Keyword: Sleep
Link ID: 26343 - Posted: 06.20.2019

Bethany Brookshire When researchers release a new finding about the brain, it’s often mice or rats who have run the mazes and taken the tests for science. People might wonder: Are rodents good substitutes for humans? Maybe for men, but what about women? That’s less likely, because most neuroscience experiments don’t use female rodents — a fact one scientist says comes from outdated ideas that should go into the scientific dustbin. For years, many scientists have dismissed female rodents as too variable to use in the lab, with tricky hormone surges that can affect behavior and compromise study results. In 2009, male lab mammals in neuroscience studies outnumbered females 5.5 to 1, according to a 2011 study in Neuroscience & Biobehavioral Reviews. “The idea that women are primarily driven by ovarian hormones [was] a narrative put in place intentionally in the Victorian era,” says Rebecca Shansky, a neuroscientist at Northeastern University in Boston. “That has also infiltrated the way we think about female animals” in science. Male animals can be just as “hormonal” as their female counterparts, Shansky argues in an essay published May 31 in Science, and it’s time that both sexes got equal attention in the lab. Here are five things to know about the issue of sex in the study of rodent brains. In humans, reproductive hormones such as estrogen and progesterone ebb and flow over a roughly 28-day cycle. In rodents, that cycle is compressed to four or five days. Estrogen or progesterone levels on one day could be up to four times as much as on the day before. |© Society for Science & the Public 2000 - 2019

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 26342 - Posted: 06.20.2019

By Tim Vernimmen The image above, “A Sunday Afternoon on the Island of La Grande Jatte,” was painted in 1884 by French artist Georges Seurat. The black lines crisscrossing it are not the work of a toddler wreaking havoc with a permanent marker, but that of neuroscientist Robert Wurtz of the National Eye Institute in the US. Ten years ago, he asked a colleague to look at the painting while wearing a contact lens–like contraption that recorded the colleague’s eye movements. These were then translated into the graffiti you see here. Art lovers may cringe, yet it is likely that Seurat would have been intrigued by this augmentation of his work. The movement Seurat kick-started with this painting — Neo-Impressionism — drew inspiration from the scientific study of how our vision works. Particularly influential was the pioneering research of Hermann von Helmholtz, a German physician, physicist and philosopher and author of a seminal 1867 book, Handbook of Physiological Optics, on the way we perceive depth, color and motion. One of the questions that occupied Helmholtz, and quite possibly Seurat, is why we don’t perceive the constant eye movements we make when we are scanning our surroundings (or a painted representation of them). Consider that the lines above were drawn in just three minutes. If we saw all those movements as we made them, our view of the world would be a blur of constant motion. As Wurtz and his Italian colleagues Paola Binda and Maria Concetta Morrone explain in two articles in the Annual Review of Vision Science, there’s a lot we know about why that doesn’t happen — and more yet to learn.

Keyword: Vision
Link ID: 26341 - Posted: 06.20.2019

A mother has laid bare the "brutal reality" of bringing up her adoptive son after he was left damaged by exposure to alcohol in the womb. Judith Knox says her 12-year-old son has a range of behavioural problems as a result of Foetal Alcohol Spectrum Disorder (FASD). It is estimated that as many as 172,000 people could be affected by the disorder in Scotland. But Ms Knox said it took six years for her son to be properly diagnosed. FASD is an umbrella term that describes the adverse physical and emotional conditions that affect people whose mother drank during pregnancy. A new support service for parents and carers, called FASD Hub Scotland, has now been launched. Ms Knox, who does not want to name her son or identify him through recent pictures, said the service was long overdue. She told BBC Scotland: "This has put a lot of strain on the family. "Your parenting is always being scrutinised and he just wants 100% of your attention, 100% of the time." The 51-year-old and her ex-husband adopted their son at the age of seven months and he quickly began to exhibit a raft of worrying behaviour. This included biting his fingers until they bled in a bid to stave off sleep, picking plaster from the walls to eat and ignoring the range of toys his family had bought him. Her son was eventually diagnosed with FASD at the age of six, after doctors initially wrongly thought he had Attention Deficit Hyperactivity Disorder. But his behaviour continued to push his family to their limits.

Keyword: Development of the Brain; Drug Abuse
Link ID: 26340 - Posted: 06.20.2019

By Michele C. Hollow My son often asks, “What do you have against jokes?” “Nothing,” I reply. “Well, stop killing them,” he says. He’s 18, autistic, and does standup. He has learned the importance of delivery and timing, skills mastered by the best comics. Despite this, many people believe people with autism are humorless. Tell that to Jerry Seinfeld, Michael Palin and Dan Aykroyd. All identify themselves as having autism spectrum disorder, or A.S.D. One of Mr. Aykroyd’s symptoms included an obsession with ghosts and law enforcement. His deep interest in the ghost hunter Hans Holzer inspired him to co-write “Ghostbusters.” “It’s a huge myth that people with A.S.D. don’t understand or are not interested in humor,” said Thomas Frazier, chief science officer at Autism Speaks, an advocacy organization that sponsors research and conducts awareness and outreach activities. “And the types of humor they like, understand, and even don’t get comes down to the individual. It’s the same with neurotypicals. It’s all about teaching the mechanics of it, and once you are comfortable with it, you come to appreciate it.” Of course, the autism spectrum is broad, and some people on it may appreciate certain jokes more than others. “Humor is personal, individualized, and people process jokes differently,” Dr. Frazier said. A 2018 study published in the journal Psychological Reports found people on the spectrum struggle with jokes that defy logic and familiarity. The setup is followed by a punch line with a twist. “Having a joke take you on a totally different path from the setup is disconcerting,” Dr. Frazier said. “A lot of people with autism don’t like incongruous humor.” © 2019 The New York Times Company

Keyword: Autism; Emotions
Link ID: 26339 - Posted: 06.19.2019

Paul GabrielsenPaul Gabrielsen For everyone who's looked into an infant's sparkling eyes and wondered what goes on in its little fuzzy head, there's now an answer. New research shows that babies display glimmers of consciousness and memory as early as 5 months old. For decades, neuroscientists have been searching for an unmistakable signal of consciousness in electrical brain activity. Such a sign could determine whether minimally conscious or anesthetized adults are aware—and when consciousness begins in babies. Studies on adults show a particular pattern of brain activity: When your senses detect something, such as a moving object, the vision center of your brain activates, even if the object goes by too fast for you to notice. But if the object remains in your visual field for long enough, the signal travels from the back of the brain to the prefrontal cortex, which holds the image in your mind long enough for you to notice. Scientists see a spike in brain activity when the senses pick something up, and another signal, the "late slow wave," when the prefrontal cortex gets the message. The whole process takes less than one-third of a second. Researchers in France wondered if such a two-step pattern might be present in infants. The team monitored infants' brain activity through caps fitted with electrodes. More than 240 babies participated, but two-thirds were too squirmy for the movement-sensitive caps. The remaining 80 (ages 5 months, 12 months, or 15 months) were shown a picture of a face on a screen for a fraction of a second. © 2018 Condé Nast

Keyword: Consciousness; Development of the Brain
Link ID: 26338 - Posted: 06.19.2019

By Madison Dapcevich An optical illusion designed by researchers to test how contrast deceives the brain appears to show a diamond moving across the screen, twitching up and down and left to right, without ever physically changing location. Dubbed the “Perceptual Diamond”, the illusion “produces motion continuously and unambiguously” to trick the viewer into thinking it is moving around the screen, yet it remains steady and slightly illuminated. Rather, its motion is mimicked by changing the contrast between the edges of strips around the diamond’s edges and the background. Shifts in contrasts around the edges, like in this illusion, can create the perception of motion. The Perpetual Diamond illusion provides no clues as to its orientation or direction until it is animated, generating movement through contrast signals alone, wrote the authors in i-Perception. "We often take the perception of motion for granted because we assume that motion corresponds to objects shifting location in the real world," explained study author Arthur Shapiro, from the American University in Washington DC, in an email to IFLScience. "However, the brain has many processes that can lead to the perception of motion, and there are many types of images that can stimulate these processes." Depending on the combination of illuminated edges, the diamond will appear to move in different directions. For example, if the two top edges blink between black and white and the two bottom edges do the opposite, the diamond appears to continuously move upward.

Keyword: Vision
Link ID: 26337 - Posted: 06.19.2019

By Benedict Carey Last winter, several dozen people who were struggling with suicidal urges and bouts of intense emotion opened their lives to a company called Mindstrong, in what has become a closely watched experiment in Silicon Valley. Mindstrong, a venture co-founded by a former director of the National Institute of Mental Health, promised something that no drug or talk therapy can provide: an early-warning system that would flag the user when an emotional crisis seemed imminent — a personal, digital “fire alarm.” For the past year, California state and county mental health officials, along with patient representatives, have met regularly with Mindstrong and another company, 7 Cups, to test smartphone apps for people receiving care through the state’s public mental health system. Officials from 13 counties and two cities are involved, and the apps are already available to the public. The new users, most of whom have a diagnosis of borderline personality disorder, receive treatment through the Los Angeles County mental health network, and were among the first test subjects in this collaboration. They allowed Mindstrong to digitally install an alternate keyboard on their smartphones, embedded in the app, and to monitor their moment-to-moment screen activity. “People with borderline personality disorder have a very difficult time identifying when distress is very high,” said Lynn McFarr, director of the cognitive and dialectical behavior therapy clinic at Harbor U.C.L.A. Medical Center, which provides care for people in the Los Angeles County system. “If we can show them, in this biofeedback fashion, that the signals went off the rails yesterday, say, after they got into a fight with a co-worker, then they’d be able to anticipate that emotion and target it with the skills they’ve learned.” The potential for digital technology to transform mental health care is enormous, and some 10,000 apps now crowd the market, each promising to soothe one psychological symptom or another. Smartphones allow near continuous monitoring of people with diagnoses such as depression, anxiety and schizophrenia, disorders for which few new treatments are available. But there has been little research to demonstrate whether such digital supports are effective. © 2019 The New York Times Company

Keyword: Schizophrenia; Depression
Link ID: 26336 - Posted: 06.18.2019

Ian Sample Science editor In a project that has all the makings of a Roald Dahl classic, scientists have hit on an answer to the mystery of how man’s best friend got its puppy dog eyes. The sad, imploring expression held such power over humans during 33,000 years of canine domestication that the preference for dogs that could pull off the look steered the evolution of their facial muscles, researchers have said. The result is that dogs gradually acquired a new forehead muscle named the levator anguli oculi medialis, or LAOM, and have used it to deploy the doleful look to devastating effect ever since. “They are very powerful animals in how they capture our hearts,” said Prof Bridget Waller, the director of the Centre for Comparative and Evolutionary Psychology at the University of Portsmouth. “We pay a lot of attention to faces, they are meaningful to us, and this expression makes dogs look juvenile and sad. It induces a nurturing response. It’s a cute factor.” Puppy dog eyes are achieved by the LAOM raising the inner eyebrows, in some cases quite dramatically. The movement makes the eyes look larger and the face more babyish. Humans use different muscles to produce a similar expression when they are sad, which may explain why it brings out the caregiver in people. To investigate how the look developed in dogs, the UK-US research team acquired wolf and dog cadavers from taxidermists and US state organisations and dissected their heads to compare the facial muscles. No animals were killed for the research. © 2019 Guardian News & Media Limited

Keyword: Emotions; Evolution
Link ID: 26335 - Posted: 06.18.2019

By Jane E. Brody Shakespeare wisely recognized that sleep “knits up the ravell’d sleave of care” and relieves life’s physical and emotional pains. Alas, this “chief nourisher in life’s feast,” as he called it, often eludes millions of people who suffer from insomnia. Desperate to fall asleep or fall back to sleep, many resort to Ambien or another of the so-called “Z drugs” to get elusive shut-eye. But except for people with short-term sleep-disrupting issues, like post-surgical pain or bereavement, these sedative-hypnotics have a time-limited benefit and can sometimes cause more serious problems than they might prevent. They should not be used for more than four or five weeks. In April, the Food and Drug Administration added a boxed warning to the prescription insomnia drugs zolpidem (Ambien, Edluar, Intermezzo and Zolpimist), zaleplon (Sonata) and eszopiclone (Lunesta) following reports of injury and death from sleepwalking, sleep-driving and engaging in other hazardous activities while not fully awake. Last July, a Georgia woman was arrested when she drove the wrong way on a highway the day after using Ambien, as prescribed, to help her sleep. Although she had consumed no alcohol, she flunked a standard sobriety test and told police she was unaware of how she ended up going the wrong way. Although extreme reactions to these sleep drugs are thought to be uncommon, they are unpredictable and can be disastrous when they occur. Some have resulted in vehicular fatalities. As many as 20 percent to 30 percent of people in the general population sleep poorly. They may have difficulty falling asleep or staying asleep, some awaken much too early, while others do not feel rested despite spending a full night seemingly asleep in bed. For one person in 10, insomnia is a chronic problem that repeats itself night after night. Little wonder that so many resort to sleeping pills to cope with it. © 2019 The New York Times Company

Keyword: Sleep
Link ID: 26334 - Posted: 06.18.2019

By Matthew Hutson LONG BEACH, CALIFORNIA—Spies may soon have another tool to carry out their shadowy missions: a new device that uses sound to “see” around corners. David Lindell Previously, researchers developed gadgets that bounced light waves around corners to catch reflections and see things out of the line of sight. To see whether they could do something similar with sound, another group of scientists built a hardware prototype—a vertical pole adorned with off-the-shelf microphones and small car speakers. The speakers emitted a series of chirps, which bounced off a nearby wall at an angle before hitting a hidden object on another wall—a poster board cutout of the letter H. Scientists then moved their rig bit by bit, each time making more chirps, which bounced back the way they came, into the microphones. Using algorithms from seismic imaging, the system reconstructed a rough image of the letter H (above). The researchers also imaged a setup with the letters L and T and compared their acoustic results with an optical method. The optical method, which requires expensive equipment, failed to reproduce the more-distant L, and it took more than an hour, compared with just 4.5 minutes for the acoustic method. The researchers will present the work here Wednesday at the Computer Vision and Pattern Recognition conference. © 2019 American Association for the Advancement of Science

Keyword: Hearing
Link ID: 26333 - Posted: 06.18.2019

By Austin Frakt The idea that legal cannabis can help address the opioid crisis has generated much hope and enthusiasm. Opioid misuse has declined in recent years at the same time that cannabis use has been increasing, with many states liberalizing marijuana laws. Based on recent research, some advocates have been promoting this connection, arguing that easier access to marijuana reduces opioid use and, in turn, overdose deaths. A new study urges caution. Sometimes appearances — or statistics — can be deceiving. Why people were so hopeful It’s plausible that marijuana can help reduce pain. Systematic reviews show that certain compounds found in marijuana or synthetically produced cannabinoids do so, at least for some conditions. So some people who might otherwise seek out opioid painkillers could use medical marijuana instead. Regulations in some states, including New York, that streamline access to medical marijuana are based on the idea that it can substitute for opioids in pain treatment. In 2014, a study published in JAMA gave further hope that liberalizing marijuana laws might alleviate the opioid crisis. The study examined the years 1999 through 2010, during which 10 states established medical marijuana programs. It compared changes in the rates of opioid painkiller deaths in states that passed medical marijuana laws with those that had not. The results? Researchers found that the laws were associated with a nearly 25 percent decline in the death rate from opioid painkillers. © 2019 The New York Times Company

Keyword: Drug Abuse
Link ID: 26332 - Posted: 06.18.2019

National Institutes of Health scientists have used human skin cells to create what they believe is the first cerebral organoid system, or “mini-brain,” for studying sporadic Creutzfeldt-Jakob disease (CJD). CJD is a fatal neurodegenerative brain disease of humans believed to be caused by infectious prion protein. It affects about 1 in 1 million people. The researchers, from NIH’s National Institute of Allergy and Infectious Diseases (NIAID), hope the human organoid model will enable them to evaluate potential therapeutics for CJD and provide greater detail about human prion disease subtypes than the rodent and nonhuman primate models currently in use. Human cerebral organoids are small balls of human brain cells ranging in size from a poppy seed to a small pea. Their organization, structure, and electrical signaling are similar to brain tissue. Because these cerebral organoids can survive in a controlled environment for months, nervous system diseases can be studied over time. Cerebral organoids have been used as models to study Zika virus infection, Alzheimer’s disease, and Down syndrome. In a new study published in Acta Neuropathologica Communications, scientists at NIAID’s Rocky Mountain Laboratories discovered how to infect five-month-old cerebral organoids with prions using samples from two patients who died of two different CJD subtypes, MV1 and MV2. Infection took about one month to confirm, and the scientists monitored the organoids for changes in health indicators, such as metabolism, for more than six months. By the end of the study, the scientists observed that seeding activity, an indication of infectious prion propagation, was present in all organoids exposed to the CJD samples. However, seeding was greater in organoids infected with the MV2 sample than the MV1 sample. They also reported that the MV1-infected organoids showed more damage than the MV2-infected organoids.

Keyword: Prions; Development of the Brain
Link ID: 26331 - Posted: 06.15.2019

By Simon Makin Better Memory through Electrical Brain Ripples Hippocampus Neuron, computer illustration Credit: Kateryna Kon Getty Images Specific patterns of brain activity are thought to underlie specific processes or computations important for various mental faculties, such as memory. One such “brain signal” that has received a lot of attention recently is known as a “sharp wave ripple”—a short, wave-shaped burst of high-frequency oscillations. Researchers originally identified ripples in the hippocampus, a region crucially involved in memory and navigation, as central to diverting recollections to long-term memory during sleep. Then a 2012 study by neuroscientists at the University of California, San Francisco, led by Loren Frank and Shantanu Jadhav, the latter now at Brandeis University, showed that the ripples also play a role in memory while awake. The researchers used electrical pulses to disrupt ripples in rodents’ brains, and showed that, by doing so, performance in a memory task was reduced. However, nobody had manipulated ripples to enhance memory—until now, that is. Researchers at NYU School of Medicine led by neuroscientist György Buzsáki have now done exactly that. In a June 14 study in Science, the team showed that prolonging sharp wave ripples in the hippocampus of rats significantly improved their performance in a maze task that taxes working memory—the brain’s “scratch pad” for combining and manipulating information on the fly. “This is a very novel and impactful study,” says Jadhav, who was not involved in the research. “It’s very hard to do ‘gain-of-function’ studies with physiological processes in such a precise way.” As well as revealing new details about how ripples contribute to specific memory processes, the work could ultimately have implications for efforts to develop interventions for disorders of memory and learning. © 2019 Scientific American

Keyword: Learning & Memory
Link ID: 26330 - Posted: 06.15.2019