By Anahad O’Connor Five years ago, a group of nutrition scientists studied what Americans eat and reached a striking conclusion: More than half of all the calories that the average American consumes comes from ultra-processed foods, which they defined as “industrial formulations” that combine large amounts of sugar, salt, oils, fats and other additives. Highly processed foods continue to dominate the American diet, despite being linked to obesity, heart disease, Type 2 diabetes and other health problems. They are cheap and convenient, and engineered to taste good. They are aggressively marketed by the food industry. But a growing number of scientists say another reason these foods are so heavily consumed is that for many people they are not just tempting but addictive, a notion that has sparked controversy among researchers. Recently, the American Journal of Clinical Nutrition explored the science behind food addiction and whether ultra-processed foods might be contributing to overeating and obesity. It featured a debate between two of the leading experts on the subject, Ashley Gearhardt, associate professor in the psychology department at the University of Michigan, and Dr. Johannes Hebebrand, head of the department of child and adolescent psychiatry, psychosomatics and psychotherapy at the University of Duisburg-Essen in Germany. Dr. Gearhardt, a clinical psychologist, helped develop the Yale Food Addiction Scale, a survey that is used to determine whether a person shows signs of addictive behavior toward food. In one study involving more than 500 people, she and her colleagues found that certain foods were especially likely to elicit “addictive-like” eating behaviors, such as intense cravings, a loss of control, and an inability to cut back despite experiencing harmful consequences and a strong desire to stop eating them. At the top of the list were pizza, chocolate, potato chips, cookies, ice cream, French fries and cheeseburgers. © 2021 The New York Times Company

Keyword: Obesity; Drug Abuse
Link ID: 27706 - Posted: 02.23.2021

By Kelly Servick Put human stem cells in a lab dish with the right nutrients, and they’ll do their best to form a little brain. They’ll fail, but you’ll get an organoid: a semiorganized clump of cells. Organoids have become a powerful tool for studying brain development and disease, but researchers assumed these microscopic blobs only mirror a brain’s prenatal development—its earliest and simplest stages. A study today reveals that with enough time, organoid cells can take on some of the genetic signatures that brain cells display after birth, potentially expanding the range of disorders and developmental stages they can recreate. “Things that, before I saw this paper, I would have said you can’t do with organoids … actually, maybe you can,” says Madeline Lancaster, a developmental geneticist at the Medical Research Council’s Laboratory of Molecular Biology. For example, Lancaster wasn’t optimistic about using organoids to study schizophrenia, which is suspected to emerge in the brain after birth, once neural communication becomes more complex. But she now wonders whether cells from a person with this disorder—once “reprogrammed” to a primitive, stem cell state and coaxed to mature within a brain organoid—could reveal important cellular differences underlying the condition. Stanford University neurobiologist Sergiu Pașca has been making brain organoids for about 10 years, and his team has learned that some of these tissue blobs can thrive in a dish for years. In the new study, they teamed up with neurogeneticist Daniel Geschwind and colleagues at the University of California, Los Angeles (UCLA), to analyze how the blobs changed over their life spans. © 2021 American Association for the Advancement of Science.

Keyword: Development of the Brain
Link ID: 27705 - Posted: 02.23.2021

By Richard Sima Sign up for Science Times: Get stories that capture the wonders of nature, the cosmos and the human body. Though it is well-known for its many arms, the octopus does not seem to know where those eight appendages are most of the time. “In the octopus, you have no bones and no joints, and every point in its arm can go to every direction that you can think about,” said Nir Nesher, a senior lecturer in marine sciences at the Ruppin Academic Center in Israel. “So even one arm, it’s something like endless degrees of freedom.” So how does the octopus keep all those wiggly, sucker-covered limbs out of trouble? According to a study published this month in The Journal of Experimental Biology by Dr. Nesher and his colleagues, the octopus’s arms can sense and respond to light — even when the octopus cannot see it with the eyes on its head. This light-sensing ability may help the cephalopods keep their arms concealed from other animals that could mistake the tip of an arm for a marine worm or some other kind of meal. Itamar Katz, one of the study’s authors, first noticed the light-detecting powers while studying a different phenomenon: how light causes the octopus’s skin to change color. With Dr. Nesher and Tal Shomrat, another author, Mr. Katz saw that shining light on an arm caused the octopus to withdraw it, even when the creature was sleeping. Further experiments showed that the arms would avoid the light in situations when the octopus could not see it with its eyes. Even when the octopuses reached an arm out of a small opening on an opaque, covered aquarium for food, the arm would quickly retract when light was shined on it 84 percent of the time. This was a surprise, as though the octopus “can see the light through the arm, it can feel the light through the arm,” Dr. Nesher said. “They don’t need the eye for that.” ImageScientists suspect octopuses keep their arms concealed from other animals that could mistake the tip of an arm for a meal. Scientists suspect octopuses keep their arms concealed from other animals that could © 2021 The New York Times Company

Keyword: Vision; Evolution
Link ID: 27704 - Posted: 02.23.2021

By Sui-Lee Wee Mark Lewis was desperate to find monkeys. Millions of human lives, all over the world, were at stake. Mr. Lewis, the chief executive of Bioqual, was responsible for providing lab monkeys to pharmaceutical companies like Moderna and Johnson & Johnson, which needed the animals to develop their Covid-19 vaccines. But as the coronavirus swept across the United States last year, there were few of the specially bred monkeys to be found anywhere in the world. Unable to furnish scientists with monkeys, which can cost more than $10,000 each, about a dozen companies were left scrambling for research animals at the height of the pandemic. “We lost work because we couldn’t supply the animals in the time frame,” Mr. Lewis said. The world needs monkeys, whose DNA closely resembles that of humans, to develop Covid-19 vaccines. But a global shortage, resulting from the unexpected demand caused by the pandemic, has been exacerbated by a recent ban on the sale of wildlife from China, the leading supplier of the lab animals. The latest shortage has revived talk about creating a strategic monkey reserve in the United States, an emergency stockpile similar to those maintained by the government for oil and grain. As new variants of the coronavirus threaten to make the current batch of vaccines obsolete, scientists are racing to find new sources of monkeys, and the United States is reassessing its reliance on China, a rival with its own biotech ambitions. The pandemic has underscored how much China controls the supply of lifesaving goods, including masks and drugs, that the United States needs in a crisis. American scientists have searched private and government-funded facilities in Southeast Asia as well as Mauritius, a tiny island nation off southeast Africa, for stocks of their preferred test subjects, rhesus macaques and cynomolgus macaques, also known as long-tailed macaques. But no country can make up for what China previously supplied. Before the pandemic, China provided over 60 percent of the 33,818 primates, mostly cynomolgus macaques, imported into the United States in 2019, according to analyst estimates based on data from the Centers for Disease Control and Prevention. © 2021 The New York Times Company

Keyword: Animal Rights
Link ID: 27703 - Posted: 02.23.2021

By Thomas Nail What are you thinking about right now? Have you ever wondered why it's so hard to answer this simple question when someone asks? There is a reason. 95 percent of your brain's activity is entirely unconscious. Of the remaining 5 percent of brain activity, only around half is intentionally directed. The vast majority of what goes on in our heads is unknown and unintentional. Neuroscientists call these activities "spontaneous fluctuations," because they are unpredictable and seemingly unconnected to any specific behavior. No wonder it's so hard to say what we are thinking or feeling and why. We like to think of ourselves as CEOs of our own minds, but we are much more like ships tossed at sea. What does this reveal about the nature of consciousness? Why is our brain, a mere 2 percent of our body mass, using 20 percent of our energy to produce what many scientists still call "background noise?" Neuroscientists have known about these "random" fluctuations in electrical brain activity since the 1930s, but have not known what to make of them until relatively recently. Many brain studies of consciousness still look only at brain activity that responds to external stimuli and triggers a mental state. The rest of the "noise" is "averaged out" of the data. This is still the prevailing approach in most contemporary neuroscience, and yields a "computational" input-output model of consciousness. In this neuroscientific model, so-called "information" transfers from our senses to our brains. Yet the pioneering French neuroscientist Stanislas Dehaene considers this view "deeply wrong." "Spontaneous activity is one of the most frequently overlooked features" of consciousness, he writes. Unlike engineers who design digital transistors with discrete voltages for 0s and 1s to resist background noise, neurons in the brain work differently.

Keyword: Consciousness; Attention
Link ID: 27702 - Posted: 02.23.2021

By Nicholas Bakalar A large analysis looked at hundreds of factors that may influence the risk of heart failure and found one dietary factor in particular that was associated with a lower risk: drinking coffee. Heart failure, sometimes called congestive heart failure, occurs when the heart muscle becomes weakened and can no longer pump blood efficiently. It can be caused by high blood pressure, heart valve disease, heart attack, diabetes and other diseases and conditions. The analysis included extensive, decades-long data from three large health studies with 21,361 participants, and used a method called machine learning that uses computers to find meaningful patterns in large amounts of data. “Usually, researchers pick things they suspect would be risk factors for heart failure — smoking, for example — and then look at smokers versus nonsmokers,” said the senior author, Dr. David P. Kao, an assistant professor of medicine at the University of Colorado. “But machine learning identifies variables that are predictive of either increased or decreased risk, but that you haven’t necessarily thought of.” Using this technique, Dr. Kao and his colleagues found 204 variables that are associated with the risk for heart failure. Then they looked at the 41 strongest factors, which included, among others, smoking, marital status, B.M.I., cholesterol, blood pressure and the consumption of various foods. The analysis is in Circulation: Heart Failure. In all three studies, coffee drinking was associated more strongly than any other dietary factor with a decreased long-term risk for heart failure. Drinking a cup a day or less had no effect, but two cups a day conferred a 31 percent reduced risk, and three cups or more reduced risk by 29 percent. There were not enough subjects who drank more than three cups daily to know if more coffee would decrease the risk further. © 2021 The New York Times Company

Keyword: Drug Abuse
Link ID: 27701 - Posted: 02.23.2021

By Sofia Moutinho In the movie Inception, Leonardo DiCaprio enters into other people’s dreams to interact with them and steal secrets from their subconscious. Now, it seems this science fiction plot is one baby step closer to reality. For the first time, researchers have had “conversations” involving novel questions and math problems with lucid dreamers—people who are aware that they are dreaming. The findings, from four labs and 36 participants, suggest people can receive and process complex external information while sleeping. “This work challenges the foundational definitions of sleep,” says cognitive neuroscientist Benjamin Baird of the University of Wisconsin, Madison, who studies sleep and dreams but was not part of the study. Traditionally, he says, sleep has been defined as a state in which the brain is disconnected and unaware of the outside world. Lucid dreaming got one of its first mentions in the writings of Greek philosopher Aristotle in the fourth century B.C.E., and scientists have observed it since the 1970s in experiments about the rapid eye movement (REM) phase of sleep, when most dreaming occurs. One in every two people has had at least one lucid dream, about 10% of people experience them once a month or more. Although rare, this ability to recognize you are in a dream—and even control some aspects of it—can be enhanced with training. A few studies have tried to communicate with lucid dreamers using stimuli such as lights, shocks, and sounds to “enter” people’s dreams. But these recorded only minimal responses from the sleepers and did not involve complex transmission of information. © 2021 American Association for the Advancement of Science.

Keyword: Sleep; Attention
Link ID: 27700 - Posted: 02.19.2021

By Diana Kwon Dreams are full of possibilities; by drifting into the world beyond our waking realities, we can visit magical lands, travel through time and interact with long-lost family and friends. The notion of communicating in real time with someone outside of our dreamscapes, however, sounds like science fiction. A new study demonstrates that, to some extent, this seeming fantasy can be made real. Scientists already knew that one-way contact is attainable. Previous studies have demonstrated that people can process external cues, such as sounds and smells, while asleep. There is also evidence that people are able to send messages in the other direction: Lucid dreamers—those who can become aware they are in a dream—can be trained to signal, using eye movements, that they are in the midst of a dream. Two-way communication, however, is more complex. It requires a person who is asleep to actually understand what they hear from the outside and think about it logically enough to generate an answer, explains Ken Paller, a cognitive neuroscientist at Northwestern University. “We believed that it was going to be possible—but until we actually demonstrated it, we weren’t sure.” For this study, Paller and his colleagues recruited volunteers who said they remembered at least one dream per week and provided them with guidance on how to lucid dream. They were also trained to respond to simple math problems by moving their eyes back and forth—for example, the correct answer to “eight minus six,” would be moving your eyes to the left and right twice. While the participants slept, electrodes attached to their faces picked up their eye movements and electroencephalography (EEG)—a method of monitoring brain activity—kept track of what stage of sleep they were in. © 2021 Scientific American

Keyword: Sleep; Attention
Link ID: 27699 - Posted: 02.19.2021

By Valeriya Safronova Jennifer Lopez is wearing them, Kylie Jenner and Rashida Jones are promoting them, and Drew Barrymore is selling them. Blue-light glasses are shaping up to be the accessory of our prolonged screen-mediated moment. But do we need them? Blue-light glasses are fitted with lenses that filter out certain light waves that are emitted by the sun and, to a lesser extent, by digital devices like phones, laptops and tablets. Blue light is not inherently bad; it boosts attention and wakefulness during the day. But it suppresses the natural production of melatonin at night. By limiting exposure to blue light by as little as 20 percent, companies say, a customer could sleep better, experience less eye strain and prevent potential retinal damage. Scientists, however, are not convinced that the glasses are a worthy investment. “Whichever aspect you look at, it’s very hard to justify spending the extra money,” said Dr. John Lawrenson, a professor of clinical visual science at City, University of London. (Prices vary but start at around $20.) After reviewing several studies that tested the effectiveness of blue-light-blocking lenses, he and his colleagues concluded that the glasses are not necessary. Digital eye strain is real, but it’s impossible to say with certainty that the culprit is blue light. “No one has established an independent causal association between blue light coming from the computer and visual symptoms,” Dr. Lawrenson said. He recommended going to an eye doctor for a checkup instead of rushing to buy nonprescription glasses. Regardless, the blue-light category is booming. A quick Google search pulls up several brands that almost exclusively sell “computer glasses” (like Felix Gray, which raised more than $1.7 million in funding in 2020, bringing its total funding to $7.8 million as of September, according to PitchBook), as well as prescription-eyewear companies like Zenni (which sold two million pairs of its Blokz lenses in 2020, according to the company) and Jins (which noted an uptick in online orders last year). If you’ve shopped at Warby Parker recently, you were probably asked if you’d like a blue-light filter added to your lenses. © 2021 The New York Times Company

Keyword: Sleep; Vision
Link ID: 27698 - Posted: 02.19.2021

By Cara Giaimo Platypuses do it. Opossums do it. Even three species of North American flying squirrel do it. Tasmanian devils, echidnas and wombats may also do it, although the evidence is not quite so robust. And, breaking news: Two species of rabbit-size rodents called springhares do it. That is, they glow under black light, that perplexing quirk of certain mammals that is baffling biologists and delighting animal lovers all over the world. Springhares, which hop around the savannas of southern and eastern Africa, weren’t on anyone’s fluorescence bingo card. Like the other glowing mammals, they are nocturnal. But unlike the other creatures, they are Old World placental mammals, an evolutionary group not previously represented. Their glow, a unique pinkish-orange the authors call “funky and vivid,” forms surprisingly variable patterns, generally concentrated on the head, legs, rear and tail. Fluorescence is a material property rather than a biological one. Certain pigments can absorb ultraviolet light and re-emit it as a vibrant, visible color. These pigments have been found in amphibians and some birds, and are added to things like white T-shirts and party supplies. But mammals, it seems, don’t tend to have these pigments. A group of researchers, many associated with Northland College in Ashland, Wis., has been chasing down exceptions for the past few years — ever since one member, the biologist Jonathan Martin, happened to wave a UV flashlight at a flying squirrel in his backyard. It glowed eraser pink. © 2021 The New York Times Company

Keyword: Vision; Evolution
Link ID: 27697 - Posted: 02.19.2021

By Gary Stix A consensus has emerged in recent years that psychotherapies—in particular, cognitive behavioral therapy (CBT)—rate comparably to medications such as Prozac and Lexapro as treatments for depression. Either option, or the two together, may at times alleviate the mood disorder. In looking more closely at both treatments, CBT—which delves into dysfunctional thinking patterns—may have a benefit that could make it the better choice for a patient.The reason may be rooted in our deep evolutionary past. Scholars suggest humans may become depressed to help us focus attention on a problem that might cause someone to fall out of step with family, friends, clan or the larger society—an outcast status that, especially in Paleolithic times, would have meant an all-but-certain tragic fate. Depression, by this account, came about as a mood state to make us think long and hard about behaviors that may have caused us to become despondent because some issue in our lives is socially problematic. A recent article in American Psychologist, the flagship publication of the American Psychological Association, weighs what the possible evolutionary origins of depression might mean for arguments about the merits of psychotherapy versus antidepressants. In the article, Steven D. Hollon, a professor of psychology at Vanderbilt University, explores the implications of helping a patient come to grips with the underlying causes of a depression—which is the goal of CBT, and is also in line with an evolutionary explanation. The anodyne effects of an antidepressant, by contrast, may divert a patient from engaging in the reflective process for which depression evolved—a reason perhaps that psychotherapy appears to produce a more enduring effect than antidepressants. Scientific American spoke with Hollon about his ideas on the topic.

Keyword: Depression
Link ID: 27696 - Posted: 02.17.2021

By Cathleen O’Grady As Samuel West combed through a paper that found a link between watching cartoon violence and aggression in children, he noticed something odd about the study participants. There were more than 3000—an unusually large number—and they were all 10 years old. “It was just too perfect,” says West, a Ph.D. student in social psychology at Virginia Commonwealth University. Yet West added the 2019 study, published in Aggressive Behavior and led by psychologist Qian Zhang of Southwest University of Chongqing, to his meta-analysis after a reviewer asked him to cast a wider net. West didn’t feel his vague misgivings could justify excluding it from the study pool. But after Aggressive Behavior published West’s meta-analysis last year, he was startled to find that the journal was investigating Zhang’s paper while his own was under review. It is just one of many papers of Zhang’s that have recently been called into question, casting a shadow on research into the controversial question of whether violent entertainment fosters violent behavior. Zhang denies any wrongdoing, but two papers have been retracted. Others live on in journals and meta-analyses—a “major problem” for a field with conflicting results and entrenched camps, says Amy Orben, a cognitive scientist at the University of Cambridge who studies media and behavior. And not just for the ivory tower, she says: The research shapes media warning labels and decisions by parents and health professionals. © 2021 American Association for the Advancement of Science.

Keyword: Aggression; Development of the Brain
Link ID: 27695 - Posted: 02.17.2021

In a study led by National Institutes of Health researchers, scientists found that five genes may play a critical role in determining whether a person will suffer from Lewy body dementia, a devastating disorder that riddles the brain with clumps of abnormal protein deposits called Lewy bodies. Lewy bodies are also a hallmark of Parkinson’s disease. The results, published in Nature Genetics, not only supported the disease’s ties to Parkinson’s disease but also suggested that people who have Lewy body dementia may share similar genetic profiles to those who have Alzheimer’s disease. “Lewy body dementia is a devastating brain disorder for which we have no effective treatments. Patients often appear to suffer the worst of both Alzheimer’s and Parkinson’s diseases. Our results support the idea that this may be because Lewy body dementia is caused by a spectrum of problems that can be seen in both disorders,” said Sonja Scholz, M.D., Ph.D., investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS) and the senior author of the study. “We hope that these results will act as a blueprint for understanding the disease and developing new treatments.” The study was led by Dr. Scholz’s team and researchers in the lab of Bryan J. Traynor, M.D., Ph.D., senior investigator at the NIH’s National Institute on Aging (NIA). Lewy body dementia usually affects people over 65 years old. Early signs of the disease include hallucinations, mood swings, and problems with thinking, movements, and sleep. Patients who initially have cognitive and behavioral problems are usually diagnosed as having dementia with Lewy bodies, but are sometimes mistakenly diagnosed with Alzheimer’s disease. Alternatively, many patients, that are initially diagnosed with Parkinson’s disease, may eventually have difficulties with thinking and mood caused by Lewy body dementia. In both cases, as the disease worsens, patients become severely disabled and may die within eight years of diagnosis.

Keyword: Alzheimers; Parkinsons
Link ID: 27694 - Posted: 02.17.2021

By Isobel Whitcomb It began with a pulled muscle. Each day after school, as the sun sank dusky purple over the hills of my hometown, I’d run with my track teammates. Even on our easy days, I’d bound ahead, leaving them behind. It wasn’t that I thought myself better than them—it’s that when I ran fast, and focused on nothing but the cold air burning my lungs and my feet pounding, my normally anxious thoughts turned to white noise. Until, one day, something popped in my leg. I stopped. I limped a little, and then tried running again: sharp, hot pain radiated down my thigh. Panic flooded me, as I imagined weeks without running: weeks without a predictable break from my own thoughts, weeks immersed in adolescent loneliness. I was 14. Pain was about to define a decade of my life. Advertisement First, I took a break from the sport—five months of stretching, icing, and waiting for the leg to heal. I returned to running, but soon after, I developed a throbbing pain in my back. The cycle repeated. Less than a year later, the pain showed up again, this time in my foot. My focus on healing my body became singular: I tried physical therapy and massage and acupuncture. I researched conditions that could lead to repeat injury. Maybe I had a rare soft-tissue disorder, I thought, or maybe early-onset rheumatoid arthritis. I let an osteopath stick a giant needle into my spinal ligaments, and inject me with sugar water, which is just as painful as it sounds. After a chiropractor recommended an anti-inflammatory diet, I subsisted on only meat and vegetables. I’d get a few good months—a joyful summer, a successful cross-country season. Then the pain would return again. As I prepared to leave home for college, my knees and ankles throbbed. For several months, my hip hurt so badly I dreaded even walking to the dining hall. Then, while scrambling to finish my senior thesis, neck spasms prevented me from leaving my bed for days. When I saw doctors, I hoped that they would discover something terribly wrong. They never did. “Have you tried psychotherapy?” one asked me. I had. I’d been in therapy for years. © 2021 The Slate Group LLC.

Keyword: Pain & Touch; Attention
Link ID: 27693 - Posted: 02.15.2021

By Sabrina Imbler Over the course of her 32 years, Cheyenne the red-bellied lemur has had many soul mates. Her first was a mate in the traditional sense, a male red-bellied lemur who lived monogamously with Cheyenne for many years at the Duke Lemur Center in Durham, N.C. When he died, the elderly Cheyenne moved on to Geb, a geriatric crowned lemur; his young mate, Aria, had recently left him for a an even younger lemur. Cheyenne and Geb shared several years of peaceful, platonic companionship until Geb died in 2018 at the venerable age of 26. Cheyenne now lives with Chloris, a 32-year-old ring-tailed lemur who has full cataracts in one eye and arthritis in her tail. The two spend their days as many couples do, elderly or not: sleeping, hanging out, grooming each other and cuddling. “Right now Chloris and Cheyenne are snuggled up like a yin-yang symbol,” Britt Keith, the head lemur keeper, said on a call from the D wing of the center, which houses many of the center’s geriatric lemurs. The goal of Cheyenne and Chloris’s pairing is not for them to breed; the lemurs are both post-reproductive females. Rather, it is companionship, the comfort of having someone to spend your twilight days with and a soft body to snuggle up to at night — and, in Cheyenne and Chloris’s case, also during the day. “They sleep a lot,” Ms. Keith said. In the wild, lemurs generally do not want for company. Red-bellied lemurs form extremely tight, long-term bonds with their mates, and pairs rarely stray more than than three dozen feet apart, according to Stacey Tecot, a lemur primatologist at the University of Arizona. Crowned lemurs like Geb and ring-tailed lemurs like Chloris are not monogamous but have rich social lives, said Nicholas Grebe, a postdoctoral researcher who studies lemur behavior at Duke University and who knows Cheyenne and Chloris. © 2021 The New York Times Company

Keyword: Emotions; Pain & Touch
Link ID: 27692 - Posted: 02.15.2021

By William Weir There are a few ways we perceive food, and not all are particularly well-understood. We know that much of it happens in the olfactory bulb, a small lump of tissue between the eyes and behind the nose, but how the stimuli arrive at this part of the brain is still being worked out. How these stimuli are processed in the brain plays a major role in our daily life. Fully understanding how our perceptions of food are formed is critical, Fahmeed Hyder said, but getting a clear picture of what our brains do when we smell has been tricky. “Knowing which exact pathways are affected and teaching our brain to appreciate and acknowledge both modes of perception in understanding the flavor is a part of our culture that we haven’t fully exploited yet,” he said. A better understanding of how smells get to our brain would not only tell us a lot about our eating habits, he said, it could even potentially help patients of certain diseases. Hyder, professor of biomedical engineering and radiology & biomedical imaging, has taken a detailed look at the function of the olfactory bulb. It may not be one of the most talked-about regions of the brain, but it helps us make sense of the outside world by taking in molecules from food — known as food volatiles — and then sending these signals further into the brain. It serves a pivotal role as the gateway for chemical stimuli to the rest of the brain — specifically the piriform cortex, amygdala, and hippocampus. To see exactly how it does that, Hyder and his team mapped the activity in the entire olfactory bulb. It’s the first time that this has ever been done for the two independent routes of odor delivery — that is, the orthonasal and retronasal routes. The results were published in NeuroImage. Copyright © 2021 Yale University

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27691 - Posted: 02.15.2021

By Leslie Nemo Ironically, this tangle of brain cells is helping scientists tease apart a larger problem: how to help people with Alzheimer’s disease. Matheus Victor, a researcher at the Massachusetts Institute of Technology, photographed these neurons after coaxing them to life in a petri dish in the hope that the rudimentary brain tissue will reveal why a new therapy might alleviate Alzheimer’s symptoms. In humans and mice, a healthy memory is associated with a high level of synced neurons that turn on and off simultaneously. Those with neurological conditions such as Alzheimer’s and Parkinson’s disease often have fewer brain cells blinking unanimously. A couple of years ago Victor’s lab leader Li-Huei Tsai and her team at M.I.T. found that when they surrounded mice genetically predisposed to Alzheimer’s with sound pulses beating 40 times a second, the rodents performed better on memory-related tasks. The animals also lost some amyloid plaques, protein deposits in the brain that are characteristic of the disease. The researchers had previously performed a similar study with light flickering at the same rate, and the mice were found to experience additional improvements when the sound and light pulses were combined. Astoundingly, the mouse neurons synced up to the 40-beats-per-second rhythm of the audio pulses, though the mechanism behind this result and the reason the shift improves symptoms remain a mystery. To help solve it, the researchers want to watch how brain tissue responds to the stimulants at the cellular level. The goal is to one day understand how this exposure treatment might work for people, so the team is growing human brain cells in the lab and engineering them to respond to sound and light without eyes and ears. “We are trying to mimic the sensory stimulation in mice but missing a lot of the hardware that makes it possible. So this is a bit of a hack,” Victor says. © 2021 Scientific American

Keyword: Alzheimers; Brain imaging
Link ID: 27690 - Posted: 02.15.2021

By Alex Vadukul In the early 1970s, the field of neuroradiology was still in its formative years, and among its early practitioners was Dr. John Bentson, at UCLA Medical Center in Los Angeles. As he helped patients with the aid of new technology like the CT scan and computer imaging, he saw an opportunity for innovation. A subspecialty of radiology, neuroradiology involves diagnosing and treating ailments in the brain, spinal cord and nerves. One tool used in treatment is the combination of an angiographic guidewire and catheter, essentially a slender wire and tube. Inserted through the leg, it can aid with the injection of contrast dye for diagnostic brain imaging and the treatment of aneurysms. At the time, however, guidewires were rigid and at worst could injure a blood vessel. Dr. Bentson decided to design a better type. He conceived of a more supple guidewire that also featured a flexible tip, and after UCLA built an early prototype for him, other neuroradiologists started using his model. Cook Medical began manufacturing the device in 1973, and it’s still in use today, commonly known as a Bentson guidewire. Dr. Bentson died at 83 on Dec. 28 at a hospital in Los Angeles. The cause was complications of Covid-19, his daughter Dr. Erika Drazan said. “He liked to push boundaries if he thought he could help the patient,” she said. “He liked saying that the vessels in the body are just like a tree, and that he could get where he wanted through them by feel.” Thousands of patients have benefited from his innovation, The American Society of Neuroradiology said after his death. John Reinert Bentson was born on May 15, 1937, in Viroqua, Wis., to Carl and Stella (Hagen) Bentson, who were of Norwegian heritage. He was raised on his family’s dairy farm, going to school in the winter on wooden skis. His mother prepared Norwegian fare like lutefisk. © 2021 The New York Times Company

Keyword: Brain imaging; Stroke
Link ID: 27689 - Posted: 02.15.2021

By Gina Kolata For the first time, a drug has been shown so effective against obesity that patients may dodge many of its worst consequences, including diabetes, researchers reported on Wednesday. The drug, semaglutide, made by Novo Nordisk, already is marketed as a treatment for Type 2 diabetes. In a clinical trial published in the New England Journal of Medicine, researchers at Northwestern University in Chicago tested semaglutide at a much higher dose as an anti-obesity medication. Nearly 2,000 participants, at 129 centers in 16 countries, injected themselves weekly with semaglutide or a placebo for 68 weeks. Those who got the drug lost close to 15 percent of their body weight, on average, compared with 2.4 percent among those receiving the placebo. More than a third of the participants receiving the drug lost more than 20 percent of their weight. Symptoms of diabetes and pre-diabetes improved in many patients. Those results far exceed the amount of weight loss observed in clinical trials of other obesity medications, experts said. The drug is a “game-changer,” said Dr. Robert F. Kushner, an obesity researcher at Northwestern University Feinberg School of Medicine, who led the study. “This is the start of a new era of effective treatments for obesity.” Dr. Clifford Rosen of Maine Medical Center Research Institute, who was not involved in the trial, said, “I think it has a huge potential for weight loss.” Gastrointestinal symptoms among the participants were “really marginal — nothing like with weight loss drugs in the past,” added Dr. Rosen, an editor at the New England Journal of Medicine and a co-author of an editorial accompanying the study. For decades, scientists have searched for ways to help growing numbers of people struggling with obesity. Five currently available anti-obesity drugs have side effects that limit their use. The most effective, phentermine, brings about a 7.5 percent weight loss, on average, and can be taken only for a short time. After it is stopped, even that amount of weight is regained. © 2021 The New York Times Company

Keyword: Obesity
Link ID: 27688 - Posted: 02.13.2021

Ariana Remmel Researchers have created tiny, brain-like ‘organoids’ that contain a gene variant harboured by two extinct human relatives, Neanderthals and Denisovans. The tissues, made by engineering human stem cells, are far from being true representations of these species’ brains — but they show distinct differences from human organoids, including size, shape and texture. The findings, published1 in Science on 11 February, could help scientists to understand the genetic pathways that allowed human brains to evolve. Can lab-grown brains become conscious? “It’s an extraordinary paper with some extraordinary claims,” says Gray Camp, a developmental biologist at the University of Basel in Switzerland, whose lab last year reported2 growing brain organoids that contained a gene common to Neanderthals and humans. The latest work takes the research further by looking at gene variants that humans lost in evolution. But Camp remains sceptical about the implications of the results, and says the work opens more questions that will require investigation. Humans are more closely related to Neanderthals and Denisovans than to any living primate, and some 40% of the Neanderthal genome can still be found spread throughout living humans. But researchers have limited means to study these ancient species’ brains — soft tissue is not well preserved, and most studies rely on inspecting the size and shape of fossilized skulls. Knowing how the species’ genes differ from humans’ is important because it helps researchers to understand what makes humans unique — especially in our brains. © 2021 Springer Nature Limited

Keyword: Development of the Brain; Evolution
Link ID: 27687 - Posted: 02.13.2021