Nicola Davis Science correspondent From loud snores to twitching paws, dogs often appear to have a penchant for a good snooze. But researchers have said elderly canines with dementia appear to spend less time slumbering than those with healthy brains – mirroring patterns seen in humans. It has long been known that people with dementia can experience sleep problems, including finding it harder to get to sleep. Researchers have also found changes in the brainwaves of people with dementia during sleep – including decreased slow brain waves that occur during non-rapid eye movement deep sleep. These are important in memory consolidation and appear to be linked to the activity of the brain’s system for clearing away waste. Now it seems sleep impairment may occur in dogs experiencing a condition similar to dementia in humans. “Changes in sleep habits should be expected in older dogs, and could be a harbinger of decline in cognition,” said Prof Natasha Olby, senior author of a study at North Carolina State University. Writing in the journal Frontiers in Veterinary Science, Olby and colleagues reported on their study of 28 dogs aged between 10 and 16 years old. The canines’ brainwaves were recorded by electroencephalogram (EEG) while the dogs took a two-hour afternoon nap. The researchers also assessed owners’ answers to a questionnaire and each dog’s performance on a range of problem-solving, memory and attention tasks, to provide a score indicating whether the dog had, or was at risk of, canine dementia. Twenty of the dogs were deemed to have cognitive impairment, with this judged to be severe in eight of them. Combining their data, the team found dogs with higher dementia scores took longer to fall asleep and spent less time sleeping. © 2023 Guardian News & Media Limited

Keyword: Alzheimers; Sleep
Link ID: 28760 - Posted: 04.29.2023

by Kyle H. Kallman In 2010, when I was 18, a sleep study confirmed what kids at sleepovers and camp, and my freshman-year dorm mate who slept with headphones blaring heavy metal, already knew: I snored, and very loudly. The breathing passages in my nose, throat and mouth weren’t staying open, forcing my brain to wake up from deep sleep and open my airways. Over 30 times an hour. I awoke each morning exhausted. At the time, I thought it was normal to feel terrible every morning. “He’s a typical teenager,” said my mom when I slept in until the evening on weekends. My dad’s solution was pouring water on me so I could “seize the day!” I was a regular night owl who hated mornings. I never felt fully awake until the afternoon. Kyle H. Kallman wears a mask for his CPAP machine. (Kyle H. Kallman) But my physician suggested I get tested for sleep apnea since my levels of sleepiness were off the charts, even for a teen. And he warned me that the health effects of sleep apnea over time could be bad: stroke, heart problems, diabetes, and in some cases, even a shortened life span. A specialist looked at my test and said I needed a continuous positive airway pressure machine, a clunky contraption that sits beside your bed and straps on your face at night, providing a little constant air pressure that basically keeps your airways open as you sleep. No way was I going to do that. Sleep apnea seemed like a problem for old people — most CPAP users start at age 55 — and I was living in a college dorm and dating. If I ever brought somebody back to my college dorm room, they’d see the dorky machine on my nightstand and any possibility of romance would end. Besides, I didn’t think snoring was a big deal — I didn’t hear it.

Keyword: Sleep
Link ID: 28759 - Posted: 04.29.2023

By Aimee Cunningham Fentanyl, a deadly synthetic opioid, is killing a growing number of children and teens in the United States. More than 1,500 kids under the age of 20 died from fentanyl in 2021, four times as many as in 2018, says epidemiologist Julie Gaither of the Yale School of Medicine, who will present the data May 1 at the Pediatric Academic Societies meeting in Washington, D.C. The fentanyl deaths account for nearly all of the opioid-related deaths in this age group in 2021. Fentanyl is a lab-made opioid used for pain treatment that is 30 to 50 times more potent than heroin, making it lethal at a much smaller dose. The drug is also manufactured and sold illegally and is increasingly found contaminating counterfeit prescription drugs, or entirely replacing the drug a buyer expects to get (SN: 5/1/18). “That’s primarily the story of what’s happening among teenagers,” says pediatrician and addiction provider Sarah Bagley of the Boston University Chobanian & Avedisian School of Medicine. They intend to purchase and use one kind of drug or substance but unknowingly ingest fentanyl. “People are not anticipating that they are going to be exposed to fentanyl, and then they are, and that results in an overdose.” Some of the signs that a person is experiencing an overdose include falling asleep, losing consciousness, gurgling or choking sounds and weak or no breathing. “This change in the drug supply, where you just have a much more potent opioid, is really driving it all,” says Bagley, who was not involved in the work. © Society for Science & the Public 2000–2023.

Keyword: Drug Abuse
Link ID: 28758 - Posted: 04.29.2023

By Geoffrey Giller From the brightly colored poison frogs of South America to the prehistoric-looking newts of the Western US, the world is filled with beautiful, deadly amphibians. Just a few milligrams of the newt’s tetrodotoxin can be fatal, and some of those frogs make the most potent poisons found in nature. In recent years, scientists have become increasingly interested in studying poisonous amphibians and are starting to unravel the mysteries they hold. How is it, for example, that the animals don’t poison themselves along with their would-be predators? And how exactly do the ones that ingest toxins in order to make themselves poisonous move those toxins from their stomachs to their skin? Even the source of the poison is sometimes unclear. While some amphibians get their toxins from their diet, and many poisonous organisms get theirs from symbiotic bacteria living on their skin, still others may or may not make the toxins themselves — which has led scientists to rethink some classic hypotheses. Over the long arc of evolution, animals have often turned to poisons as a means of defense. Unlike venoms — which are injected via fang, stinger, barb, or some other specialized structure for offensive or defensive purposes — poisons are generally defensive toxins a creature makes that must be ingested or absorbed before they take effect. Amphibians tend to store their poisons in or on their skin, presumably to increase the likelihood that a potential predator is deterred or incapacitated before it can eat or grievously wound them. Many of their most powerful toxins — like tetrodotoxin, epibatidine and the bufotoxins originally found in toads — are poisons that interfere with proteins in cells, or mimic key signaling molecules, thus disrupting normal function. © 2023 Annual Reviews

Keyword: Neurotoxins
Link ID: 28757 - Posted: 04.29.2023

By Kate Golembiewski On the one hand, this headgear looks like something a cyberfish would wear. On the other, it’s not far from a fashion statement someone at the Kentucky Derby might make. But scientists didn’t just affix this device for laughs: They are curious about the underlying brain mechanisms that allow fish to navigate their world, and how such mechanisms relate to the evolutionary roots of navigation for all creatures with brain circuitry. “Navigation is an extremely important aspect of behavior because we navigate to find food, to find shelter, to escape predators,” said Ronen Segev, a neuroscientist at Ben-Gurion University of the Negev in Israel who was part of a team that fitted 15 fish with cybernetic headgear for a study published on Tuesday in the journal PLOS Biology. Putting a computer on a goldfish to study how the neurons fire in its brain while navigating wasn’t easy. It takes a careful hand because a goldfish’s brain, which looks a bit like a small cluster of lentils, is only half an inch long. “Under a microscope, we exposed the brain and put the electrodes inside,” said Lear Cohen, a neuroscientist and doctoral candidate at Ben-Gurion who performed the surgeries to attach the devices. Each of those electrodes was the diameter of a strand of human hair. It was also tricky to find a way to perform the procedure on dry land without harming the test subject. “The fish needs water and you need him not to move,” he said. He and his colleagues solved both problems by pumping water and anesthetics into the fish’s mouth. Once the electrodes were in the brain, they were connected to a small recording device, which could monitor neuronal activity and which was sealed in a waterproof case, mounted on the fish’s forehead. To keep the computer from weighing the fish down and impeding its ability to swim, the researchers attached buoyant plastic foam to the device. © 2023 The New York Times Company

Keyword: Learning & Memory
Link ID: 28756 - Posted: 04.26.2023

Ruth Ogden A year and half alone in a cave might sound like a nightmare to a lot of people, but Spanish athlete Beatriz Flamini emerged with a cheerful grin and said she thought she had more time to finish her book. She had almost no contact with the outside world during her impressive feat of human endurance. For 500 days, she documented her experiences to help scientists understand the effects of extreme isolation. One of the first things that became apparent on April 12 2023 when she emerged from the cave was how fluid time is, shaped more by your personality traits and the people around you than a ticking clock. When talking to reporters about her experiences, Flamini explained she rapidly lost her sense of time. The loss of time was so profound that, when her support team came to retrieve her, she was surprised that her time was up, instead believing she had only been there for 160-170 days. Our actions, emotions and changes in our environment can have powerful effects on the way in which our minds process time. For most people, the rising and setting of the sun mark the passing of days, and work and social routines mark the passing of hours. In the darkness of an underground cave, without the company of others, many signals of passing of time will have disappeared. So Flamini may have become more reliant on psychological processes to monitor time. One way in which we keep track of the passage of time is memory. If we don’t know how long we have been doing something for, we use the number of memories formed during the event as an index to the amount of time that has passed. The more memories we form in an event or era, the longer we perceive it to have lasted. © 2010–2023, The Conversation US, Inc.

Keyword: Attention; Biological Rhythms
Link ID: 28755 - Posted: 04.26.2023

By Darius Tahir & Hannah Norman, KHN Suzette Zuena is her own best advertisement for weight loss. Zuena, the “founder/visionary” of LH Spa & Rejuvenation in Livingston and Madison, New Jersey, has dropped 30 pounds. Her husband has lost 42 pounds. “We go out a lot,” Zuena said of the pair’s social routine. “People saw us basically shrinking.” They would ask how the couple did it. Her response: point people to her spa and a relatively new type of medication — GLP-1 agonists, a class of drug that’s become a weight loss phenomenon. But she’s not just spreading her message in person. She’s also doing it on Instagram. And she’s not alone. A chorus of voices is singing these drugs’ praises. Last summer, investment bank Morgan Stanley found mentions of one of these drugs on TikTok had tripled. People are streaming into doctors’ office to inquire about what they’ve heard are miracle drugs. What these patients have heard, doctors said, is nonstop hype, even misinformation, from social media influencers. “I’ll catch people asking for the skinny pen, the weight loss shot, or Ozempic,” said Priya Jaisinghani, an endocrinologist and clinical assistant professor at New York University’s Grossman School of Medicine. Competition to claim a market that could be worth $100 billion a year for drugmakers alone has triggered a wave of advertising that has provoked the concern of regulators and doctors worldwide. But their tools for curbing the ads that go too far are limited — especially when it comes to social media. Regulatory systems are most interested in pharma’s claims, not necessarily those of doctors or their enthused patients.

Keyword: Obesity
Link ID: 28754 - Posted: 04.26.2023

By Rebecca Robbins The Food and Drug Administration on Tuesday authorized the first drug for a rare genetic form of the neurological disorder A.L.S., despite uncertainty about the treatment’s effectiveness. The decision reflects the agency’s push toward greater flexibility in approving treatments for patients with devastating illnesses and few, if any, options. Biogen, the pharmaceutical company bringing the drug to market, said it would price the drug “within a range comparable to other recently launched A.L.S. treatments.” An A.L.S. therapy approved last year was priced at $158,000 annually. The drug, which is known scientifically as tofersen and will be sold under the brand name Qalsody, targets a mutation in a gene known as SOD1 that is present in about 2 percent of the roughly 6,000 cases of A.L.S. diagnosed in the United States each year. Fewer than 500 people in the United States at any given time are expected to be eligible. The agency authorized the treatment via a policy that allows a drug to be fast-tracked onto the market under certain circumstances before there is conclusive proof that it works. Biogen will be required to provide confirmatory evidence, from ongoing clinical research, to keep the drug on the market. The decision is the first conditional approval granted for a medication for A.L.S., or amyotrophic lateral sclerosis, which generally causes paralysis and death within a few years. Fewer than half the patients eligible for Qalsody survive more than three years after their diagnosis. The approval is based on evidence that the drug can significantly reduce levels of a protein that has been linked to damage to nerve cells. Biogen has argued that these results are reasonably likely to help patients, even though the drug, in a clinical trial, did not significantly slow the progression of the disease, as measured by patients’ ability to speak, swallow and perform other activities of daily living. © 2023 The New York Times Company

Keyword: ALS-Lou Gehrig's Disease
Link ID: 28753 - Posted: 04.26.2023

By Laurie McGinley — When Rebecca Chopp was diagnosed with early-stage Alzheimer’s disease, she and her husband did the only thing that seemed to make sense: They went to their favorite Mexican restaurant, held each other in a back booth and drank margaritas. And cried. After a while, they helped each other back across the street to their home. Chopp, at 67, was chancellor of the University of Denver, at the pinnacle of a career powered by a daunting intellect and relentless work. She was also an ordained minister, prolific author and former president of Swarthmore College and Colgate University. Sometimes, Chopp thought of herself as a brain with a body attached. The changes were subtle: Chopp was sleeping more. She got lost on the way to the doctor. Then came the diagnosis. (Joanna Kulesza/For The Washington Post ) Now, she was crushed, facing the loss of that beautiful mind. She worried she would soon be an empty shell, drooling and unkempt, a burden to the people she loved. “There is a sense that when you are diagnosed, you are immediately going to descend into madness,” Chopp said. When she relinquished the job she loved, Chopp fell into deep despair, confounded by the prescription given to her by an empathetic doctor: “Live with joy!” She had nightmares about going insane. But, eventually, she began to push back against the darkness. Chopp has mild cognitive impairment, a condition that involves subtle changes in thinking and memory and that, in most cases, leads to Alzheimer’s dementia, a fatal neurodegenerative disease that affects more than 6.7 million Americans. Using diet, exercise and joy to slow Alzheimer’s For years, there was little doctors could do for people with Alzheimer’s, even at a very early stage. Now, changes are coming in how the disease is diagnosed and treated, and patients with mild cognitive impairment are at the center of the efforts. Lacking a cure, scientists are trying desperately to delay the worst phase of the illness.

Keyword: Alzheimers
Link ID: 28752 - Posted: 04.26.2023

By Emily Underwood The ability to set a goal and pursue it without getting derailed by temptations or distractions is essential to nearly everything we do in life, from finishing homework to driving safely in traffic. It also places complex demands on the brain, requiring skills like working memory — the ability to keep small amounts of information in mind to perform a task — as well as impulse control and being able to rapidly adapt when rules or circumstances change. Taken together, these elements add up to something researchers call executive function. We all struggle with executive function sometimes, for example when we’re stressed or don’t get enough sleep. But in teenagers, these powers are still a work in progress, contributing to some of the contradictory behaviors and lapses in judgment — “My honor roll student did what on TikTok?” — that baffle many parents. This erratic control can be dangerous, especially when teens make impulsive choices. But that doesn’t mean the teen brain is broken, says Beatriz Luna, a developmental cognitive neuroscientist at the University of Pittsburgh and coauthor of a review on the maturation of one aspect of executive function, called cognitive control, in the 2015 Annual Review of Neuroscience. Adolescents have all the basic neural circuitry needed for executive function and cognitive control, Luna says. In fact, they have more than they need — what’s lacking is experience, which over time will strengthen some neural pathways and weaken or eliminate others. This winnowing serves an important purpose: It tailors the brain to help teens handle the demands of their unique, ever-changing environments and to navigate situations their parents may never have encountered. Luna’s research suggests that teens’ inconsistent cognitive control is key to becoming independent, because it encourages them to seek out and learn from experiences that go beyond what they’ve been actively taught. © 2023 Annual Reviews

Keyword: Development of the Brain; Attention
Link ID: 28751 - Posted: 04.26.2023

By Carolyn Todd Any sleep tracker will show you that slumber is far from a passive affair. And no stage of sleep demonstrates that better than rapid eye movement, or REM, commonly called dream sleep. “It’s also called paradoxical sleep or active sleep, because REM sleep is actually very close to being awake,” said Dr. Rajkumar Dasgupta, a sleep medicine and pulmonary specialist at the Keck School of Medicine of the University of Southern California. Before scientists discovered REM sleep in the 1950s, it wasn’t clear that much of anything was happening in the brain at night. Researchers today, however, understand sleep as a highly active process composed of very different types of rest — including REM, which in some ways doesn’t seem like rest at all. While the body typically remains “off” during REM sleep, the brain is very much “on.” It’s generating vivid dreams, as well as synthesizing memories and knowledge. Scientists are still working to unravel exactly how this strange state of consciousness works. “It is fair to say that there is a lot left to learn about REM sleep,” Dr. Dasgupta said. But from what researchers do understand, REM is critical to our emotional health and brain function — and potentially even our longevity. Where does REM sleep fall in the sleep cycle? Throughout the night, “We’re going in and out of this rhythmic, symphonic pattern of the various stages of sleep: non-REM 1, 2, 3 and REM,” said Rebecca Robbins, an instructor in medicine at Harvard Medical School and an associate scientist in the division of sleep and circadian disorders at Brigham and Women’s Hospital. As you doze off, you enter the first stage of non-REM. This lasts less than 10 minutes and is considered a light sleep. Your breathing and heart rate decelerate and your muscles relax as you slip into the second stage of non-REM sleep, where your body temperature drops and your brain waves get slower. Then you enter the third stage, known as deep sleep, when your body repairs your bones and muscles, strengthens your immune system, releases hormones and restores your energy. © 2023 The New York Times Company

Keyword: Sleep
Link ID: 28750 - Posted: 04.26.2023

By R. Douglas Fields Dazzling intricacies of brain structure are revealed every day, but one of the most obvious aspects of brain wiring eludes neuroscientists. The nervous system is cross-wired, so that the left side of the brain controls the right half of the body and vice versa. Every doctor relies upon this fact in performing neurological exams, but when I asked my doctor last week why this should be, all I got was a shrug. So I asked Catherine Carr, a neuroscientist at the University of Maryland, College Park. “No good answer,” she replied. I was surprised — such a fundamental aspect of how our brain and body are wired together, and no one knew why? Nothing that we know of stops the right side of the brain from connecting with the right side of the body. That wiring scheme would seem much simpler and less prone to errors. In the embryonic brain, the crossing of the wires across the midline — an imaginary line dividing the right and left halves of the body — requires a kind of molecular “traffic cop” to somehow direct the growing nerve fibers to the right spot on the opposite side of the body. Far simpler just to keep things on the same side. Yet this neural cross wiring is ubiquitous in the animal kingdom — even the neural connections in lowly nematode worms are wired with left-right reversal across the animal’s midline. And many of the traffic cop molecules that direct the growth of neurons in these worms do the same in humans. For evolution to have conserved this arrangement so doggedly, surely there’s some benefit to it, but biologists still aren’t certain what it is. An intriguing answer, however, has come from the world of mathematics. The key to that solution lies in exactly how neural circuits are laid out within brain tissue. Neurons that make connections between the brain and the body are organized to create a virtual map in the cerebral cortex. If a neuroscientist sticks an electrode into the brain and finds that neurons there receive input from the thumb, for example, then neurons next to it in the cerebral cortex will connect to the index finger. This mapping phenomenon is called somatotopy, Greek for “body mapping,” but it’s not limited to the physical body. The 3D external world we perceive through vision and our other senses is mapped onto the brain in the same way. All Rights Reserved © 2023

Keyword: Laterality; Development of the Brain
Link ID: 28749 - Posted: 04.22.2023

By Nora Bradford The classical view of how the human brain controls voluntary movement might not tell the whole story. That map of the primary motor cortex — the motor homunculus — shows how this brain region is divided into sections assigned to each body part that can be controlled voluntarily (SN: 6/16/15). It puts your toes next to your ankle, and your neck next to your thumb. The space each part takes up on the cortex is also proportional to how much control one has over that part. Each finger, for example, takes up more space than a whole thigh. A new map reveals that in addition to having regions devoted to specific body parts, three newfound areas control integrative, whole-body actions. And representations of where specific body parts fall on this map are organized differently than previously thought, researchers report April 19 in Nature. Research in monkeys had hinted at this. “There is a whole cohort of people who have known for 50 years that the homunculus isn’t quite right,” says Evan Gordon, a neuroscientist at Washington University School of Medicine in St. Louis. But ever since pioneering brain-mapping work by neurosurgeon Wilder Penfield starting in the 1930s, the homunculus has reigned supreme in neuroscience. Gordon and his colleagues study synchronized activity and communication between different brain regions. They noticed some spots in the primary motor cortex were linked to unexpected areas involved in action control and pain perception. Because that didn’t fit with the homunculus map, they wrote it off as a result of imperfect data. “But we kept seeing it, and it kept bugging us,” Gordon says. So the team gathered functional MRI data on volunteers as they performed various tasks. Two participants completed simple movements like moving just their eyebrows or toes, as well as complex tasks like simultaneously rotating their wrist and moving their foot from side to side. The fMRI data revealed which parts of the brain activated at the same time as each task was done, allowing the researchers to trace which regions were functionally connected to one another. Seven more participants were recorded while not doing any particular task in order to look at how brain areas communicate during rest. © Society for Science & the Public 2000–2023.

Keyword: Brain imaging
Link ID: 28748 - Posted: 04.22.2023

Max Kozlov The bizarre-looking ‘homunculus’ is one of neuroscience’s most fundamental diagrams. Found in countless textbooks, it depicts a deformed constellation of body parts mapped onto a narrow strip of the brain, showing the corresponding brain regions that control each part. But a study published in Nature1 on 19 April reveals that this brain strip, called the primary motor cortex, is much more complex than the famous diagram suggests. It might coordinate complex movements involving multiple muscles through connections to brain regions responsible for critical thinking, maintaining the body’s physiology and planning actions. The new results could help scientists better understand and treat brain injuries. “This study is very interesting and very important,” says Michael Graziano, a neuroscientist at Princeton University in New Jersey. It’s becoming clear that the primary motor cortex isn’t “just a simple roster of muscles down the brain that control the toes to the tongue”, he says. Little man in the brain The idea of the homunculus dates to the late nineteenth century, when researchers noticed that electrically stimulating the primary motor cortex corresponded to specific body parts twitching. Later work found that some body parts, such as the hands, feet and mouth, took up a disproportionate amount of space in the primary motor cortex compared with the rest of the body. In 1937, these findings culminated with the first publication of the motor homunculus, which translates to ‘little man’ in Latin. Neurosurgeon Wilder Penfield’s 1948 diagram of the motor homunculus (left) shows the areas of the primary motor cortex that control each body part. A new study redraws the diagram (right), adding regions connected to brain areas responsible for coordinating complex movements.Credit: E. Gordon et al./Nature © 2023 Springer Nature Limited

Keyword: Brain imaging
Link ID: 28747 - Posted: 04.22.2023

By Annie Roth It long seemed as though African elephants were the champions of the all-nighter. They can get by on about two hours of sleep. Other mammals need much more, like koalas (20 hours) or you (at least seven plus at least one strong cup of coffee). But the largest living mammals on land have some competition at sea. Northern elephant seals are also able to sustain themselves on about two hours’ sleep, according to a study published Thursday in the journal Science. The study found that Northern elephant seals sleep far less at sea than they do on land, and the z’s they do catch at sea are caught hundreds of feet below the ocean’s surface. The study’s authors believe that sleeping in the deep allows the seals to power-nap without being eaten by prowling predators. Northern elephant seals, which are found along the West Coast, are champion divers that can descend to depths of 2,500 feet and stay under for about two hours. They are not as big as elephants, but males can weigh as much as a car and stretch 13 feet long. To maintain their blubbery bulk, Northern elephant seals must spend around seven months at sea each year, gorging on fish and squid. During these epic voyages, the seals are vulnerable to predation by great white sharks and killer whales. Some marine mammals, such as dolphins and fur seals, can rest half of their brain at a time. This type of slumber, known as unihemispheric sleep, enables some mammals at sea to snooze with one eye open, literally, which prevents predators from catching them off guard. However, elephant seals sleep like us, shutting down their brains completely. Jessica Kendall-Bar, now a postdoctoral fellow at the Scripps Institution of Oceanography in San Diego, wondered how Northern ​​elephant seals managed to sleep, given how much time they need to spend eating and avoiding being eaten while at sea. © 2023 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 28746 - Posted: 04.22.2023

By Jake Buehler Shimmering, gelatinous comb jellies wouldn’t appear to have much to hide. But their mostly see-through bodies cloak a nervous system unlike that of any other known animal, researchers report in the April 21 Science. In the nervous systems of everything from anemones to aardvarks, electrical impulses pass between nerve cells, allowing for signals to move from one cell to the next. But the ctenophores’ cobweb of neurons, called a nerve net, is missing these distinct connection spots, or synapses. Instead, the nerve net is fused together, with long, stringy neurons sharing a cell membrane, a new 3-D map of its structure shows. While the nerve net has been described before, no one had generated a high-resolution, detailed picture of it. It’s possible the bizarre tissue represents a second, independent evolutionary origin of a nervous system, say Pawel Burkhardt, a comparative neurobiologist at the University of Bergen in Norway, and colleagues. Superficially similar to jellyfish, ctenophores are often called comb jellies because they swim using rows of beating, hairlike combs. The enigmatic phylum is considered one of the earliest to branch off the animal tree of life. So ctenophores’ possession of a simple nervous system has been of particular interest to scientists interested in how such systems evolved. Previous genetics research had hinted at the strangeness of the ctenophore nervous system. For instance, a 2018 study couldn’t find a cell type in ctenophores with a genetic signature that corresponded to recognizable neurons, Burkhardt says. Burkhardt, along with neurobiologist Maike Kittelmann of Oxford Brookes University in England and colleagues, examined young sea walnuts (Mnemiopsis leidyi) using electron microscopes, compiling many images to reconstruct the entire net structure. Their 3-D map of a 1-day-old sea walnut revealed the funky synapse-free fusion between the five sprawling neurons that made up the tiny ctenophore’s net. © Society for Science & the Public 2000–2023.

Keyword: Evolution
Link ID: 28745 - Posted: 04.22.2023

Asher Mullard The US Food and Drug Administration (FDA) is set to rule soon on the approval of a new drug for a rare form of amyotrophic lateral sclerosis (ALS). The hotly anticipated decision is expected to signpost the agency’s vision for neurological drugs — and its willingness to be flexible in the regulation of these therapeutics. People with the disease desperately need new treatments, because they face a degenerative condition that causes neuronal death and typically leads to fatal respiratory failure within three years of symptoms appearing1. Tofersen, developed by the biotechnology firms Biogen in Cambridge, Massachusetts, and Ionis Pharmaceuticals in Carlsbad, California, did not slow patients’ decline in a phase III trial2. However, some say the trial was too short, and point out that there were signs of possible benefit, such as a reduction in a biomarker of neuronal damage and death called neurofilament light chain (NFL). Because of this, Biogen has asked the FDA to approve the drug on an ‘accelerated’ basis, to fast-track it to patients with a guarantee that future trial data will determine whether it works. If approved, tofersen will become the latest example of the agency’s evolving approach to neurological drug development, which could boost industry investment in brain diseases. A vote of confidence for the drug would also supercharge interest in using NFL as a tool to measure brain health and to test drugs in future. “This could be the start of a new era,” says Valentina Bonetto, a neuroscientist at the Mario Negri Institute for Pharmacological Research in Milan, Italy. In March, the FDA convened a panel to discuss the tofersen data set. Its nine independent advisers rallied behind accelerated approval for the drug, voting unanimously that the available evidence supports a “reasonably likely” chance that tofersen will help people with SOD1 ALS. This rare disease is caused by genetic mutations that affect the protein SOD1, leading it to form toxic clumps in motor neurons in the brain, brainstem and spinal cord. The agency usually follows the recommendations of its advisory committee. © 2023 Springer Nature Limited

Keyword: ALS-Lou Gehrig's Disease ; Neuroimmunology
Link ID: 28744 - Posted: 04.18.2023

Jon Hamilton Boys born to mothers who got COVID-19 while pregnant appear nearly twice as likely as other boys to be diagnosed with subtle delays in brain development. That's the conclusion of a study of more than 18,000 children born at eight hospitals in Eastern Massachusetts. Nearly 900 of the children were born to mothers who had COVID during their pregnancy. In the study, boys, but not girls, were more likely to be diagnosed with a range of developmental disorders in the first 18 months of life. These included delays in speech and language, psychological development and motor function, as well as intellectual disabilities. In older children, these differences are often associated with autism spectrum disorder, says Dr. Roy Perlis, a co-author of the study and a psychiatrist at Massachusetts General Hospital. But for the young children in this study, "it's way too soon to reliably diagnose autism," Perlis says. "All we can hope to detect at this point are more subtle sorts of things like delays in language and speech, and delays in motor milestones." The study, which relied on an analysis of electronic health records, was published in March in the journal JAMA Network Open. The finding is just the latest to suggest that a range of maternal infections can alter fetal brain development, especially in male offspring. For example, studies have found links between infections like influenza and cytomegalovirus, and disorders like autism and schizophrenia. "Male fetuses are known to be more vulnerable to maternal infectious exposures during pregnancy," says Dr. Andrea Edlow, the study's lead author and a maternal-fetal medicine specialist at Massachusetts General Hospital. © 2023 npr

Keyword: Development of the Brain; Sexual Behavior
Link ID: 28743 - Posted: 04.18.2023

BySara Reardon Anyone who’s ever owned a telescope has probably tried looking through the wrong end to see whether it works in reverse—that is, like a microscope. Spoiler alert: It doesn’t. Now, a team of researchers inspired by the strange eyes of a sea creature has figured out a way to do it. By flipping the mirrors and lenses used in certain types of telescopes, they have created a new kind of microscope that can be used to image samples floating in any type of liquid—even the insides of transparent organs—while retaining enough light to allow for high magnification. The design could help scientists achieve high enough magnification to study tiny structures such as the long, skinny axons that connect neurons in the brain or individual proteins or RNA molecules inside cells. “It’s nice to see even something as basic as a lens could still bring interest and there's still room there to do some work that would help a lot of people,” says Kimani Touissant, an electrical engineer at Brown University. He says the design could be useful in his work, in which he uses lasers to etch patterns into gels that mimic collagen and act as scaffolds for cells. At very high magnification, light trained on a sample can scatter around it, blurring and dimming the image. To get around that problem, scientists using traditional, lens-based microscopes cover their sample with a thin layer of oil or water, then dip their device’s lens into the liquid, minimizing the degree of light scattering. But this technique requires instruments to have different lenses for different types of liquid, making it an expensive, finicky process and limiting the ways that samples can be prepared. Enter Fabian Voigt, a molecular biologist at Harvard University and inventor of the new design. He was reading a book about animal vision when he encountered the odd case of scallops’ eyes. Unlike most animals, whose eyes feature retinas that send images to the brain, scallops have mantles covered with hundreds of tiny blue dots, each of which contains a curved mirror at its back. As light passes through each eye’s lens, its inner mirror reflects the light back onto the creature’s photoreceptors to create an image that then allows the scallop to respond to its environment.

Keyword: Brain imaging
Link ID: 28742 - Posted: 04.18.2023

Sara Reardon Octopuses and squids both use the suckers on their limbs to grapple with their prey and to taste their quarry at the same time. Now, a pair of studies describes how these animals ‘taste by touching’ — and how evolution has equipped them with the perfect sensory ability for their lifestyles1,2. The papers were published in Nature on 12 April. The research details the structure of the receptors that stud the animals’ suckers. These receptors transmit information that enables the creature to taste chemicals on a surface independently from those floating in the water. Armed with brains Cephalopods — the group that includes octopuses and squids — have long fascinated neuroscientists because their brains and sensory systems are unlike those found in any other animals. Octopuses, for instance, have more neurons in their arms than in their central brain: a structure that allows each arm to function independently as if it has its own brain3. And researchers have long known that the hundreds of suckers on each arm can both feel the environment and taste it4. Molecular biologist Nicholas Bellono at Harvard University in Cambridge, Massachusetts, and his group were studying the California two-spot octopus (Octopus bimaculoides) when they came across a distinctive structure on the surface of the animal’s tentacle cells. Bellono suspected that this structure acted as a receptor for chemicals in the octopus’s environment. He contacted neurobiologist Ryan Hibbs at the University of California San Diego, who studies receptors that are architecturally similar to the octopus structures found by Bellono’s team: both types consist of five barrel-like proteins clustered to form a hollow tube. When the researchers looked at the octopus genome, they found 26 genes for these barrel-shaped proteins, which could be shuffled to create millions of distinct five-part combinations that detect various tastes1. The researchers found that the octopus receptors tend to bind to ‘greasy’ molecules that don’t dissolve in water, suggesting that they are optimized for detecting chemicals on surfaces such as a fish’s skin, the sea floor or the octopus’s own eggs. © 2023 Springer Nature Limited

Keyword: Chemical Senses (Smell & Taste)
Link ID: 28741 - Posted: 04.15.2023