By Amber Dance Suppose a couple has two children, a boy and a girl. Chances are, they’ll both grow up with typical, healthy brains. But should either diverge from the usual route of brain development, or suffer mental health issues, their paths are likely to be different. The son’s differences might show up first. All else being equal, he’s four times more likely than his sister to be diagnosed with autism. Rates of other neurodevelopmental conditions and disabilities are also higher in boys. As he grows into a young man, his chances of developing schizophrenia will be two to three times higher than hers. When the siblings hit puberty, those relative risks will flip. The sister will be almost twice as likely to experience depression or an anxiety disorder. Much later in life, she’ll be at higher risk of developing Alzheimer’s disease. Those trends are not hard and fast rules, of course: Men can and do suffer from depression and Alzheimer’s; some girls develop autism; women aren’t immune to schizophrenia. Male and female brains are more alike than they are different. But scientists are learning that there’s more to these different risk profiles than, say, the pressures women face in a patriarchal society or the fact that women tend to live longer, giving diseases of aging time to develop. Subtle biological differences between male and female brains, and bodies, are important contributors. To explain these sex differences, there are some obvious places to look. The female’s two X chromosomes, to the male’s single copy, is one. Differing sex hormones — primarily testosterone in males and estrogen in females — is another. But a steadily growing body of research points to a less obvious influence: the cells and molecules of the immune system. © 2022 Annual Reviews

Keyword: Sexual Behavior; Neuroimmunology
Link ID: 28345 - Posted: 06.01.2022

Diana Kwon The brain is the body’s sovereign, and receives protection in keeping with its high status. Its cells are long-lived and shelter inside a fearsome fortification called the blood–brain barrier. For a long time, scientists thought that the brain was completely cut off from the chaos of the rest of the body — especially its eager defence system, a mass of immune cells that battle infections and whose actions could threaten a ruler caught in the crossfire. In the past decade, however, scientists have discovered that the job of protecting the brain isn’t as straightforward as they thought. They’ve learnt that its fortifications have gateways and gaps, and that its borders are bustling with active immune cells. A large body of evidence now shows that the brain and the immune system are tightly intertwined. Scientists already knew that the brain had its own resident immune cells, called microglia; recent discoveries are painting more-detailed pictures of their functions and revealing the characteristics of the other immune warriors housed in the regions around the brain. Some of these cells come from elsewhere in the body; others are produced locally, in the bone marrow of the skull. By studying these immune cells and mapping out how they interact with the brain, researchers are discovering that they play an important part in both healthy and diseased or damaged brains. Interest in the field has exploded: there were fewer than 2,000 papers per year on the subject in 2010, swelling to more than 10,000 per year in 2021, and researchers have made several major findings in the past few years. No longer do scientists consider the brain to be a special, sealed-off zone. “This whole idea of immune privilege is quite outdated now,” says Kiavash Movahedi, a neuroimmunologist at the Free University of Brussels (VUB). Although the brain is still seen as immunologically unique — its barriers prevent immune cells from coming and going at will — it’s clear that the brain and immune system constantly interact, he adds (see ‘The brain’s immune defences’). © 2022 Springer Nature Limited

Keyword: Neuroimmunology; Glia
Link ID: 28344 - Posted: 06.01.2022

ByVirginia Morell Babies don’t babble to sound cute—they’re taking their first steps on the path to learning language. Now, a study shows parrot chicks do the same. Although the behavior has been seen in songbirds and two mammalian species, finding it in these birds is important, experts say, as they may provide the best nonhuman model for studying how we begin to learn language. The find is “exciting,” says Irene Pepperberg, a comparative psychologist at Hunter College not involved with the work. Pepperberg herself discovered something like babbling in a famed African gray parrot named Alex, which she studied for more than 30 years. By unearthing the same thing in another parrot species and in the wild, she says, the team has shown this ability is widespread in the birds. In this study, the scientists focused on green-rumped parrotlets (Forpus passerinus)—a smaller species than Alex, found from Venezuela to Brazil. The team investigated a population at Venezuela’s Hato Masaguaral research center, where scientists maintain more than 100 artificial nesting boxes. Like other parrots, songbirds, and humans (and a few other mammal species), parrotlets are vocal learners. They master their calls by listening and mimicking what they hear. The chicks in the new study started to babble at 21 days, according to camcorders installed in a dozen of their nests. They increased the complexity of their sounds dramatically over the next week, the scientists report today in the Proceedings of the Royal Society B. The baby birds uttered strings of soft peeps, clicks, and grrs, but they weren’t communicating with their siblings or parents, says lead author Rory Eggleston, a Ph.D. student at Utah State University. Rather, like a human infant babbling quietly in their crib, a parrotlet chick made the sounds alone (see video). Indeed, most chicks started their babbling bouts when their siblings were asleep, often doing so without even opening their beaks, says Eggleston, who spent hours analyzing videos of the birds. © 2022 American Association for the Advancement of Science.

Keyword: Language; Animal Communication
Link ID: 28343 - Posted: 06.01.2022

By Gina Kolata Maya Cohen’s entree into the world of obesity medicine came as a shock. In despair over her weight, she saw Dr. Caroline Apovian, an obesity specialist at Brigham and Women’s Hospital, who prescribed Saxenda, a recently approved weight-loss drug. Ms. Cohen, who is 55 and lives in Cape Elizabeth, Maine, hastened to get it filled. Then she saw the price her pharmacy was charging: $1,500 a month. Her insurer classified it as a “vanity drug” and would not cover it. “I’m being treated for obesity,” she complained to her insurer, but to no avail. While Ms. Cohen was stunned by her insurer’s denial, Dr. Apovian was not. She says it is an all too common response from insurers when she prescribes weight-loss drugs and the universal response from Medicare drug plans. Obesity specialists despair but hope that with the advent of highly effective drugs, the situation will change. Novo-Nordisk, the maker of the medicine Dr. Apovian prescribed, and patient advocacy groups have been aggressively lobbying insurers to pay for weight-loss drugs. They also have been lobbying Congress to pass a bill that has languished through three administrations that would require Medicare to pay for the drugs. But for now, the status quo has not budged. No one disputes the problem — more than 40 percent of Americans have obesity, and most have tried repeatedly to lose weight and keep it off, only to fail. Many suffer from medical conditions that are linked to obesity, including diabetes, joint and back pain and heart disease, and those conditions often improve with weight loss. © 2022 The New York Times Company

Keyword: Obesity
Link ID: 28342 - Posted: 06.01.2022

By Laura Sanders Punishing headbutts damage the brains of musk oxen. That observation, made for the first time and reported May 17 in Acta Neuropathologica, suggests that a life full of bell-ringing clashes is not without consequences, even in animals built to bash. Although a musk ox looks like a dirty dust mop on four tiny hooves, it’s formidable. When charging, it can reach speeds up to 60 kilometers an hour before ramming its head directly into an oncoming head. People expected that musk oxen brains could withstand these merciless forces largely unscathed, “that they were magically perfect,” says Nicole Ackermans of the Icahn School of Medicine at Mount Sinai in New York City. “No one actually checked.” In fact, the brains of three wild musk oxen (two females and one male) showed signs of extensive damage, Ackermans and her colleagues found. The damage was similar to what’s seen in people with chronic traumatic encephalopathy, a disorder known to be caused by repetitive head hits (SN: 12/13/17). In the musk ox brains, a form of a protein called tau had accumulated in patterns that suggested brain bashing was to blame. In an unexpected twist, the brains of the females, who hit heads less frequently than males, were worse off than the male’s. The male body, with its heavier skull, stronger neck muscles and forehead fat pads, may cushion the blows to the brain, the researchers suspect. The results may highlight an evolutionary balancing act; the animals can endure just enough brain damage to allow them to survive and procreate. High-level brainwork may not matter much, Ackermans says. “Their day-to-day life is not super complicated.” © Society for Science & the Public 2000–2022.

Keyword: Brain Injury/Concussion; Evolution
Link ID: 28341 - Posted: 05.28.2022

Perspective by Elizabeth Grey I’m told I don’t look like a heroin addict. I am a married, middle-aged woman, a taxpaying homeowner. As privilege goes, I have it. Because I’m White, I get treated better in medical settings such as hospitals and rehabs. I have health insurance. I have access to credit. My spouse could not be more supportive. But every day for a couple of years I left my house with a river view and drove downtown in South Yonkers to meet my dealer. I know a letter carrier who once worked that neighborhood. He told me there was a time when you could buy an Uzi on his route. I knew the first time I bought heroin at age 48 that doing so probably meant the end of my life. But compared to withdrawal, that was fine by me. Looks and bias may deceive, but numbers don’t lie. The United States hit a record of overdose deaths last year. And the great, gaping hole of the response to the opioid epidemic is that withdrawal is the most important aspect, and it’s barely given lip service. I often wonder how many suicides are a result of people unable to bear it. There is no net. The window of time between putting down the drug and even a whiff of hope is too long. The only place to land is hell. The medical community and lawmakers have never appreciated what withdrawal — or getting dopesick — does to a human being. Current policies and protocols can only manufacture heroin addicts. And I was a degenerate one. One day I noticed the inspection sticker on my car had expired. But it cost $37 to get an inspection, and that was almost four bags of heroin. I could not afford it. Every dollar went toward my growing habit. © 1996-2022 The Washington Post

Keyword: Drug Abuse
Link ID: 28340 - Posted: 05.28.2022

By Lisa Sanders, M.D. “You have to take your husband to the hospital right now,” the doctor urged over the phone. “His kidneys aren’t working at all, and we need to find out why.” The woman looked at her 82-year-old spouse. He was so thin and pale. She thanked the doctor and called 911. For the past couple of months, every meal was a struggle. Swallowing food was strangely difficult. Liquids were even worse. Whatever he drank seemed to go down the wrong pipe, and he coughed and sputtered after almost every sip. It was terrifying. He saw an ear, nose and throat specialist, who scoped his mouth and esophagus. There wasn’t anything blocking the way. The doctor recommended that he get some therapy to help him strengthen the muscles he used to swallow, and until he did that, he should thicken his liquids to make drinking easier. The patient tried that once, but it was so disgusting he gave up on it. His wife was worried as she watched him eat and drink less and less. She could see that he was getting weaker every day. He had a stroke four months earlier, and since then his right foot dragged a little. But now she had to help him get out of his recliner. And he wasn’t able to drive — she had to make the 45-minute trip with him each day to his office. Finally, he agreed to see Dr. Richard Kaufman, their primary-care doctor. Kaufman was shocked by the man’s appearance, how the skin on his face hung in folds as if air had been let out of his cheeks. He’d lost nearly 40 pounds. He struggled to walk the few steps to the exam table. His right side, which was weakened by his stroke, was now matched by weakness on his left side. His stroke hadn’t done this. There was something else going on. Kaufman ordered some preliminary blood tests to try to see where the problem might lie. Those were the results that sent the couple to the emergency room. © 2022 The New York Times Company

Keyword: Neuroimmunology; Muscles
Link ID: 28339 - Posted: 05.28.2022

By Ernesto Londoño TIJUANA, Mexico — Plumes of incense swirled through the dimly lit living room as seven women took turns explaining what drove them to sign up for a weekend of psychedelic therapy at a villa in northern Mexico with sweeping ocean views. A former U.S. Marine said she hoped to connect with the spirit of her mother, who killed herself 11 years ago. An Army veteran said she had been sexually assaulted by a relative as a child. A handful of veterans said they had been sexually assaulted by fellow service members. The wife of a Navy bomb disposal expert choked up as she lamented that years of unrelenting combat missions had turned her husband into an absent, dysfunctional father. Kristine Bostwick, 38, a former Navy corpsman, said she hoped that putting her mind through ceremonies with mind-altering substances would help her make peace with the end of a turbulent marriage and perhaps ease the migraines that had become a daily torment. “I want to reset my brain from the bottom up,” she said during the introductory session of a recent three-day retreat, wiping away tears. “My kids deserve it. I deserve it.” A growing body of research into the therapeutic benefits of psychedelic therapy has generated enthusiasm among some psychiatrists and venture capitalists. Measures to decriminalize psychedelics, fund research into their healing potential and establish frameworks for their medicinal use have been passed with bipartisan support in city councils and state legislatures across the United States in recent years. Much of the expanding appeal of such treatments has been driven by veterans of America’s wars in Afghanistan and Iraq. Having turned to experimental therapies to treat post-traumatic stress disorder, traumatic brain injuries, addiction and depression, many former military members have become effusive advocates for a wider embrace of psychedelics. © 2022 The New York Times Company

Keyword: Stress; Drug Abuse
Link ID: 28338 - Posted: 05.25.2022

By Tess Joosse The mere sight of another person yawning causes many of us to open our mouths wide in mimicry. And we’re not alone—other social animals, such aschimpanzees and lions, can also catch so-called contagious yawns. It’s likely that all vertebrates yawn spontaneously to regulate inner body processes. Yawning probably arose with the evolution of jawed fishes 400 million or so years ago, says Andrew Gallup, an evolutionary biologist at State University of New York Polytechnic Institute who has spent years trying to figure out why we yawn. In a paper published this month in Animal Behavior, he reports some evidence for how contagious yawns might have evolved to keep us safe. Science chatted with Gallup about why yawning is ubiquitous—and useful. This interview has been edited for clarity and length. Q: First, let’s address a long-standing myth: Does yawning increase blood oxygen levels? A: No. Despite continued belief, research has explicitly tested that hypothesis and the results have concluded that breathing and yawning are controlled by different mechanisms. For example, there are really interesting cases of yawning in marine mammals, where the yawning occurs while the animal is submerged underwater and therefore not breathing. Q: So what does yawning actually do to the body? A: Yawning is a rather complex reflex. It’s triggered under a variety of contexts and neurophysiological changes. It primarily occurs during periods of state change, commonly following transitions of sleeping and waking. There’s research that also suggests that yawns are initiated alongside increases in cortical arousal, so yawns themselves may function to promote alertness. And there’s a growing body of research that suggests that yawning is triggered by rises in brain temperature. I’ve conducted a number of studies testing this in humans, nonhuman mammals, and even birds. © 2022 American Association for the Advancement of Science.

Keyword: Emotions; Evolution
Link ID: 28337 - Posted: 05.25.2022

By Veronique Greenwood Lovebirds, small parrots with vibrant rainbow plumage and cheeky personalities, are popular pets. They swing from ropes, cuddle with companions and race for treats in a waddling gait with all the urgency of toddlers who spot a cookie. But, along with other parrots, they also do something strange: They use their faces to climb walls. Give these birds a vertical surface to clamber up, and they cycle between left foot, right foot and beak as if their mouths were another limb. In fact, a new analysis of the forces climbing lovebirds exert reveals that this is precisely what they are doing. Somehow, a team of scientists wrote in the journal Proceedings of the Royal Society B on Wednesday, the birds and perhaps other parrot species have repurposed the muscles in their necks and heads so they can walk on their beaks, using them the way rock climbers use their arms. Climbing with a beak as a third limb is peculiar because third limbs generally are not something life on Earth is capable of producing, said Michael Granatosky, an assistant professor of anatomy at the New York Institute of Technology and an author of the new paper. “There is this very deep, deep set aspect of our biology that everything is bilateral” in much of the animal kingdom, he said. The situation makes it developmentally unlikely to grow an odd numbers of limbs for walking. Some animals have developed workarounds. Kangaroos use their tails as a fifth limb when hopping slowly, pushing off from the ground with their posteriors the same way they push with their feet. To see if parrots were using their beaks in a similar way, Dr. Granatosky and a graduate student, Melody Young, as well as their colleagues brought six rosy-faced lovebirds from a pet store into the lab. They had the birds climb up a surface that was fitted with a sensor to keep track of how much force they were exerting and in what directions. The scientists found that the propulsive force the birds applied through their beaks was similar to what they provided with their legs. What had started as a way to eat had transformed into a way to walk, with beaks as powerful as their limbs. © 2022 The New York Times Company

Keyword: Evolution
Link ID: 28336 - Posted: 05.25.2022

NPR's Sacha Pfeiffer talks with Eliot Schrefer, author of Queer Ducks (And Other Animals): The Natural World of Animal Sexuality. It's about how "natural sex" may not be as binary as some think. SACHA PFEIFFER, HOST: At its worst, a nonfiction science book about animal sexuality could read like a dry biology textbook. But that's not the kind of book Eliot Schrefer wrote. His book, called "Queer Ducks (And Other Animals): The Natural World Of Animal Sexuality," is designed to be teenager-friendly, for one thing. It's a young adult book filled with comics and humor and accessible science, and it's filled with research on the diversity of sexual behavior in the animal world. Eliot Schrefer is with us to explain more. Welcome, Eliot. ELIOT SCHREFER: Hi. I'm really happy to be here. PFEIFFER: We're glad to have you. I really liked the way you structured your book. It's basically an animal per chapter, in a way. But you also have these wonderful illustrations. You have interviews with scientists. Tell us a little bit about how you decided to make it accessible because, again, you're aiming for adolescents, as I understand it, in a nonfiction way, and they might be inclined to think nonfiction equals boring, dry textbook. SCHREFER: Right. I sort of imagine, like, we're kind of sitting in the science classroom, passing notes back and forth, and it even comes down to the doodles. There's an artist, Jules Zuckerberg, who did a one-page comic for each of the animal species that we discuss. So it's - the premise is that it's an animal GSA. PFEIFFER: A gender sexuality alliance meeting. SCHREFER: That's right. And so they're each taking a turn introducing themselves. And so the bonobo takes a turn introducing how her family works, and then the doodlebug and the dolphin and so on. PFEIFFER: Yeah, they're really great. They make the book really accessible. As we said, every chapter basically tackles an animal and something about the sexuality of that animal. Do you have a favorite or one of your favorites that you could tell us about? © 2022 npr

Keyword: Sexual Behavior
Link ID: 28335 - Posted: 05.25.2022

By Jan Hoffman Shortly after Kade Webb, 20, collapsed and died in a bathroom at a Safeway Market in Roseville, Calif., in December, the police opened his phone and went straight to his social media apps. There, they found exactly what they feared. Mr. Webb, a laid-back snowboarder and skateboarder who, with the imminent birth of his first child, had become despondent over his pandemic-dimmed finances, bought Percocet, a prescription opioid, through a dealer on Snapchat. It turned out to be spiked with a lethal amount of fentanyl. Mr. Webb’s death was one of nearly 108,000 drug fatalities in the United States last year, a record, according to preliminary numbers released this month by the Centers for Disease Control and Prevention. Law enforcement authorities say an alarming portion of them unfolded the same way as his: from counterfeit pills tainted with fentanyl that teenagers and young adults bought over social media. “Social media is almost exclusively the way they get the pills,” said Morgan Gire, district attorney for Placer County, Calif., where 40 people died from fentanyl poisoning last year. He has filed murder charges against a 20-year-old man accused of being Mr. Webb’s dealer, who pleaded not guilty. “About 90 percent of the pills that you’re buying from a dealer on social media now are fentanyl,” Mr. Gire said. The phenomenon has led to disturbing new statistics: Overdoses are now the leading cause of preventable death among people ages 18 to 45, ahead of suicide, traffic accidents and gun violence, according to federal data. Although experimental drug use by teenagers in the United States has been dropping since 2010, their deaths from fentanyl have skyrocketed, to 884 in 2021, from 253 in 2019, according to a recent study in the journal JAMA. Much as drug dealers in the 1980s and ’90s seized on pagers and burner phones to conduct business covertly, today’s suppliers have embraced modern iterations — social media and messaging apps with privacy features such as encrypted or disappearing messages. Dealers and young buyers usually spot each other on social media and then often proceed by directly messaging each other. © 2022 The New York Times Company

Keyword: Drug Abuse
Link ID: 28334 - Posted: 05.21.2022

Nicola Davis Science correspondent Mice with spinal cord injuries have shown remarkable recovery after being given a drug initially developed for people with lung disease, researchers have revealed, saying the treatment could soon be tested on humans. It is thought there are about 2,500 new spinal cord injuries in the UK every year, with some of those affected experiencing full loss of movement as a result. Despite a number of promising areas of research, at present damage to the spinal cord is not reversible. Now researchers at the University of Birmingham say a drug called AZD1236, initially developed to treat chronic obstructive pulmonary disease in humans, has shown promise in mice with spinal cord compression injuries, a type of injury often associated with motor accidents in humans, but which is also linked to conditions such as osteoarthritis. A similar drug, called AZD3342, showed comparable benefits in rats. The results, published in the journal Clinical and Translational Medicine, suggested the drugs block the action of enzymes known as MMP-9 and MMP-12 that rise after spinal cord injury. The upshot was that swelling of the spinal cord was reduced, levels of proteins linked to inflammation and pain were lowered, and breakdown of the blood-spinal cord barrier was limited. Scarring of connective tissue was also reduced. The team said that compared with injured mice not given AZD1236, those given the drug for three days showed 85% improvement in movement and sensation six weeks after the spinal injury, while their nerve function was 80% of that seen in uninjured mice. Furthermore, the benefits were similar whether the drug was given immediately after spinal injury or 24 hours later. © 2022 Guardian News & Media Limited

Keyword: Regeneration
Link ID: 28333 - Posted: 05.21.2022

By Azeen Ghorayshi Marcia Herman-Giddens first realized something was changing in young girls in the late 1980s, while she was serving as the director for the child abuse team at Duke University Medical Center in Durham, N.C. During evaluations of girls who had been abused, Dr. Herman-Giddens noticed that many of them had started developing breasts at ages as young as 6 or 7. “That did not seem right,” said Dr. Herman-Giddens, who is now an adjunct professor at the University of North Carolina Gillings School of Global Public Health. She wondered whether girls with early breast development were more likely to be sexually abused, but she could not find any data keeping track of puberty onset in girls in the United States. So she decided to collect it herself. A decade later, she published a study of more than 17,000 girls who underwent physical examinations at pediatricians’ offices across the country. The numbers revealed that, on average, girls in the mid-1990s had started to develop breasts — typically the first sign of puberty — around age 10, more than a year earlier than previously recorded. The decline was even more striking in Black girls, who had begun developing breasts, on average, at age 9. The medical community was shocked by the findings, and many were doubtful about a dramatic new trend spotted by an unknown physician assistant, Dr. Herman-Giddens recalled. “They were blindsided,” she said. But the study turned out to be a watershed in the medical understanding of puberty. Studies in the decades since have confirmed, in dozens of countries, that the age of puberty in girls has dropped by about three months per decade since the 1970s. A similar pattern, though less extreme, has been observed in boys. Although it is difficult to tease apart cause and effect, earlier puberty may have harmful impacts, especially for girls. Girls who go through puberty early are at a higher risk of depression, anxiety, substance abuse and other psychological problems, compared with peers who hit puberty later. Girls who get their periods earlier may also be at a higher risk of developing breast or uterine cancer in adulthood. © 2022 The New York Times Company

Keyword: Hormones & Behavior; Development of the Brain
Link ID: 28332 - Posted: 05.21.2022

By Daniel Bergner Caroline Mazel-Carlton began hearing voices when she was in day care. Mornings, by the time she was in middle school, a bowl of oatmeal awaited her for breakfast next to a white saucer of colorful pills. Her voices remained vibrant. They weren’t within her head; they spoke and screamed from outside her skull. They belonged to beings she could not see. The voice who had been with her longest warned of catastrophes coming for her family in Zionsville, a town north of Indianapolis, calamities tied in some unspecified way to TV images from the gulf war: fighter planes, flashes in the sky, explosions on the ground, luminous and all-consuming. A woman’s voice castigated her at school, telling her that her clothes smelled and that she had better keep her hand down, no matter that she knew the answers to the teacher’s questions. Another voice tracked her every move, its tone faintly mocking. “She’s getting out of bed now; oh, she’s walking down the hall now.” Her mix of psychotropic pills shifted, expanded: antipsychotics, mood stabilizers, an antidepressant, a benzodiazepine for anxiety, a stimulant for attention deficit. The pileup of drugs was typical; people hearing voices or having other hallucinations rarely wind up on just one medication. Multiple chemicals are prescribed, often more than one similar antipsychotic simultaneously, in an attempt to quell the psyche. This article is adapted from “The Mind and the Moon: My Brother’s Story, the Science of Our Brains, and the Search for Our Psyches,” published this month by Ecco. At most, for Mazel-Carlton, the antipsychotics sometimes succeeded in reducing her voices to a wall of sound. This could feel more assaultive than hearing them separately. The antipsychotics caused obesity — 50 pounds of new weight — and the feeling that she was losing control of her forearms and her neck. Her hands quivered and seemed to want to flap-paddle the air. To the isolation caused by the difference of her mind, the drugs added isolation from severe side effects. Her agitation and self-disgust, her terror of being barely human, drove her to twist clusters of her hair around her fingers, to yank hard. Patches of bare scalp crept into view. Classmates taunted, asking why she shook and was going bald, calling her “fat-ass” and “crackhead.” © 2022 The New York Times Company

Keyword: Schizophrenia
Link ID: 28331 - Posted: 05.18.2022

By Eiman Azim, Sliman Bensmaia, Lee E. Miller, Chris Versteeg Imagine you are playing the guitar. You’re seated, supporting the instrument’s weight across your lap. One hand strums; the other presses strings against the guitar’s neck to play chords. Your vision tracks sheet music on a page, and your hearing lets you listen to the sound. In addition, two other senses make playing this instrument possible. One of them, touch, tells you about your interactions with the guitar. Another, proprioception, tells you about your arms’ and hands’ positions and movements as you play. Together, these two capacities combine into what scientists call somatosensation, or body perception. Our skin and muscles have millions of sensors that contribute to somatosensation. Yet our brain does not become overwhelmed by the barrage of these inputs—or from any of our other senses, for that matter. You’re not distracted by the pinch of your shoes or the tug of the guitar strap as you play; you focus only on the sensory inputs that matter. The brain expertly enhances some signals and filters out others so that we can ignore distractions and focus on the most important details. How does the brain accomplish these feats of focus? In recent research at Northwestern University, the University of Chicago and the Salk Institute for Biological Studies in La Jolla, Calif., we have illuminated a new answer to this question. Through several studies, we have discovered that a small, largely ignored structure at the very bottom of the brain stem plays a critical role in the brain’s selection of sensory signals. The area is called the cuneate nucleus, or CN. Our research on the CN not only changes the scientific understanding of sensory processing, but it might also lay the groundwork for medical interventions to restore sensation in patients with injury or disease. © 2022 Scientific American

Keyword: Attention
Link ID: 28330 - Posted: 05.18.2022

By Natasha Gilbert In May of 2018, Tabitha Bird spent a memorable day with her eldest son at a comic book convention in London. Later that evening, after she made sure that her two younger kids were safely tucked up in bed, Bird gathered every sleeping tablet, antidepressant, anti-anxiety med and ibuprofen pill she could find and walked out of the house. She drove to a nearby store where she bought a big bottle of water and some acetaminophen. Then she stopped in an empty industrial park and began to take the lot. Bird woke up from a coma four days later. The 47-year-old, from a town in West Sussex in the UK, now attributes her suicide attempt and the depression leading up to it to perimenopause — the time in most women’s lives when menstrual cycles become irregular and fertility wanes. During this transition, many women experience a suite of changes, including hot flashes, disrupted sleep and mood swings. Some breeze through perimenopause with little difficulty, but many — about 45 percent to 68 percent — experience depression, symptoms of which can include low mood, a loss of interest in things and even thoughts of suicide. Women with a history of depression, like Bird — who also suffered with it while pregnant — are the most vulnerable. During perimenopause, they are twice as likely to experience debilitating full-blown depressive disorder than women who haven’t had past episodes. As researchers probe for reasons why some women fall prey to depression at this time and others don’t, a leading candidate has emerged: widely fluctuating levels of the sex hormone estrogen. Estrogen directs fertility, but mounting research shows that it also holds sway on parts of the brain involved in regulating emotion and stress. © 2022 Annual Reviews

Keyword: Depression; Hormones & Behavior
Link ID: 28329 - Posted: 05.18.2022

By Gina Kolata The very treatments often used to soothe pain in the lower back, which the Centers for Disease Control and Prevention says is the most common type of pain, might cause it to last longer, according to a new study. Managing pain with steroids and nonsteroidal anti-inflammatory drugs, like ibuprofen, can actually turn a wrenched back into a chronic condition, the study found. Some medical experts urged caution in interpreting the results too broadly. The study did not use the gold standard for medical research, which would be a clinical trial in which people with back pain would be randomly assigned to take a nonsteroidal anti-inflammatory drug or a placebo and followed to see who developed chronic pain. Instead, it involved observations of patients, an animal study and an analysis of patients in a large database. “It’s intriguing but requires further study,” said Dr. Steven J. Atlas, director of primary care practice-based research and quality improvement at Massachusetts General Hospital. Dr. Bruce M. Vrooman, a pain specialist at Dartmouth Hitchcock Medical Center in New Hampshire, agreed, but also called the study “impressive in its scope” and said that if the results hold up in a clinical trial, it could “force reconsideration of how we treat acute pain.” Dr. Thomas Buchheit, director of the regenerative pain therapies program at Duke, had a different view. “People overuse the term ‘paradigm shift’, but this is absolutely a paradigm shift,” Dr. Buchheit said. “There is this unspoken rule: If it hurts, take an anti-inflammatory, and if it still hurts, put a steroid on it,” he added. “But,” he said, the study shows that “we have to think of healing and not suppression of inflammation.” Guidelines from professional medical societies already say that people with back pain should start with nondrug treatments like exercise, physical therapy, heat or massage. Those measures turn out to be as effective as pain-suppressing drugs, without the same side effects. © 2022 The New York Times Company

Keyword: Pain & Touch
Link ID: 28328 - Posted: 05.18.2022

By Benjamin Mueller Five years ago, Tal Iram, a young neuroscientist at Stanford University, approached her supervisor with a daring proposal: She wanted to extract fluid from the brain cavities of young mice and to infuse it into the brains of older mice, testing whether the transfers could rejuvenate the aging rodents. Her supervisor, Tony Wyss-Coray, famously had shown that giving old animals blood from younger ones could counteract and even reverse some of the effects of aging. But the idea of testing that principle with cerebrospinal fluid, the hard-to-reach liquid that bathes the brain and spinal cord, struck him as such a daunting technical feat that trying it bordered on foolhardy. “When we discussed this initially, I said, ‘This is so difficult that I’m not sure this is going to work,’” Dr. Wyss-Coray said. Dr. Iram persevered, working for a year just to figure out how to collect the colorless liquid from mice. On Wednesday, she reported the tantalizing results in the journal Nature: A week of infusions of young cerebrospinal fluid improved the memories of older mice. The finding was the latest indication that making brains resistant to the unrelenting changes of older age might depend less on interfering with specific disease processes and more on trying to restore the brain’s environment to something closer to its youthful state. “It highlights this notion that cerebrospinal fluid could be used as a medium to manipulate the brain,” Dr. Iram said. Turning that insight into a treatment for humans, though, is a more formidable challenge, the authors of the study said. The earlier studies about how young blood can reverse some signs of aging have led to recent clinical trials in which blood donations from younger people were filtered and given to patients with Alzheimer’s or Parkinson’s disease. But exactly how successful those treatments might be, much less how widely they can be used, remains unclear, scientists said. And the difficulties of working with cerebrospinal fluid are steeper than those involved with blood. Infusing the fluid of a young human into an older patient is probably not possible; extracting the liquid generally requires a spinal tap, and scientists say that there are ethical questions about how to collect enough cerebrospinal fluid for infusions. © 2022 The New York Times Company

Keyword: Development of the Brain; Learning & Memory
Link ID: 28327 - Posted: 05.14.2022

By Ferris Jabr To hear more audio stories from publications like The New York Times, download Audm for iPhone or Android. On the evening of Oct. 10, 2006, Dennis DeGray’s mind was nearly severed from his body. After a day of fishing, he returned to his home in Pacific Grove, Calif., and realized he had not yet taken out the trash or recycling. It was raining fairly hard, so he decided to sprint from his doorstep to the garbage cans outside with a bag in each hand. As he was running, he slipped on a patch of black mold beneath some oak trees, landed hard on his chin, and snapped his neck between his second and third vertebrae. While recovering, DeGray, who was 53 at the time, learned from his doctors that he was permanently paralyzed from the collarbones down. With the exception of vestigial twitches, he cannot move his torso or limbs. “I’m about as hurt as you can get and not be on a ventilator,” he told me. For several years after his accident, he “simply laid there, watching the History Channel” as he struggled to accept the reality of his injury. Some time later, while at a fund-raising event for stem-cell research, he met Jaimie Henderson, a professor of neurosurgery at Stanford University. The pair got to talking about robots, a subject that had long interested DeGray, who grew up around his family’s machine shop. As DeGray remembers it, Henderson captivated him with a single question: Do you want to fly a drone? Henderson explained that he and his colleagues had been developing a brain-computer interface: an experimental connection between someone’s brain and an external device, like a computer, robotic limb or drone, which the person could control simply by thinking. DeGray was eager to participate, eventually moving to Menlo Park to be closer to Stanford as he waited for an opening in the study and the necessary permissions. In the summer of 2016, Henderson opened DeGray’s skull and exposed his cortex — the thin, wrinkled, outermost layer of the brain — into which he implanted two 4-millimeter-by-4-millimeter electrode arrays resembling miniature beds of nails. Each array had 100 tiny metal spikes that, collectively, recorded electric impulses surging along a couple of hundred neurons or so in the motor cortex, a brain region involved in voluntary movement. © 2022 The New York Times Company

Keyword: Robotics
Link ID: 28326 - Posted: 05.14.2022