By Veronique Greenwood Zipping through water like shimmering arrowheads, cuttlefish are swift, sure hunters — death on eight limbs and two waving tentacles for small creatures in their vicinity. They morph to match the landscape, shifting between a variety of hues and even textures, using tiny structures that expand and contract beneath their skin. They even seem to have depth perception, researchers using tiny 3-D vision glasses found, placing them apart from octopuses and squids. And their accuracy at striking prey is remarkable. But for cuttlefish, these physical feats in pursuit of food are not the whole story. A new study published this month in the journal Royal Society Open Science shows that there is even more to cuttlefish cognition than scientists may have known. The sea creatures appear to be capable of performing calculations that are more complicated than simply “more food is better.” Presented with a choice between one shrimp or two, they will actually choose the single shrimp when they have learned through experience that they are rewarded for this choice. While the braininess of their octopus cousins gets a lot of attention, researchers who study animal cognition have uncovered surprising talents in cuttlefish over the years. For instance, the cephalopods will hunt fewer crabs during the day if they learn that shrimp, their preferred food, is predictably available during the night. That shows that they can think ahead. Chuan-Chin Chiao, a biologist at National Tsing Hua University in Taiwan, and an author of the current paper alongside his colleague Tzu-Hsin Kuo, has found in the past that cuttlefish that are hungry will choose a bigger, harder-to-catch shrimp to attack, and those that are not will choose smaller, easier-to-catch ones. But researchers have also found that animals do not always make decisions that seem logical at first glance. Like humans, whose behavior rarely fits economists’ visions of what an ideal, rational creature would do, animals respond to their environments using learned experiences. © 2020 The New York Times Company

Keyword: Attention; Evolution
Link ID: 27637 - Posted: 12.31.2020

By Elizabeth Preston When Jessica Yorzinski chased great-tailed grackles across a field, it wasn’t a contest to see who blinked first. But she did want the birds to blink. Dr. Yorzinski had outfitted the grackles, which look a bit like crows but are in another family of birds, with head-mounted cameras pointing back at their faces. Like other birds, grackles blink sideways, flicking a semitransparent membrane across the eye. Recordings showed that the birds spent less time blinking during the riskiest parts of a flight. The finding was published Wednesday in Biology Letters. Dr. Yorzinski, a sensory ecologist at Texas A&M University, had been wondering how animals balance their need to blink with their need to get visual information about their environments. Humans, she said, “blink quite often, but when we do so we lose access to the world around us. It got me thinking about what might be happening in other species.” She worked with a company that builds eye-tracking equipment to make a custom bird-size headpiece. Because a bird’s eyes are on the sides of its head, the contraption held one video camera pointed at the left eye and one at the right, making the bird resemble a sports fan in a beer helmet. The headpiece was connected to a backpack holding a battery and transmitter. Dr. Yorzinski captured 10 wild great-tailed grackles, which are common in Texas, to wear this get-up. She used only male birds, which are big enough to carry the equipment without trouble. Each bird wore the camera helmet and backpack while Dr. Yorzinski encouraged it to fly by chasing it across an outdoor enclosure. © 2020 The New York Times Company

Keyword: Vision; Evolution
Link ID: 27636 - Posted: 12.22.2020

by Sarah DeWeerdt A drug that has been tested in clinical trials as a treatment for depression restores social memory in a mouse model of 22q11.2 deletion syndrome, according to a new study. The findings hint that the drug might also be useful to treat social cognitive difficulties in people with conditions such as autism, experts say. People who are missing one copy of a chromosomal region known as 22q11.2 have heart abnormalities, distinctive facial features and an increased risk of schizophrenia and other psychiatric conditions. About 16 percent have autism. People with the syndrome also have a smaller-than-average hippocampus, a structure that functions as the brain’s memory hub. The findings extend what researchers know about the role of the hippocampus in social behavior by suggesting that a small region of the hippocampus known as CA2 springs to life when an animal encounters an individual it hasn’t met before. A strength of the study is that it describes the basic biology of a brain circuit, shows how that circuit is disrupted in a mouse model and identifies a therapeutic target to reverse those disruptions, says Anthony LaMantia, professor of developmental disorders and genetics at Virginia Polytechnic Institute and State University in Blacksburg, who was not involved in the work. “This is one of the best papers sort of going from soup to nuts that has come out.” Previous studies showed that CA2 is crucial for social memory, the ability to recognize and remember others. “But we really didn’t have a good handle on what type of information CA2 was providing to the rest of the brain,” says study leader Steven Siegelbaum, professor of neuroscience and pharmacology at Columbia University. © 2020 Simons Foundation

Keyword: Autism; Genes & Behavior
Link ID: 27635 - Posted: 12.22.2020

Robin McKie, Science Editor Anne Abbott is a scientist on a mission. She believes large numbers of debilitating strokes can be prevented without surgical interventions. Lifestyle changes and medication alone can make massive improvements to people at risk from the thickening of their arteries. It is not an attitude that has endeared her to the medical establishment, however. For years, it has attempted to block her work while instead pressing for increasing use of carotid surgery and stents, she told the Observer last week. “I was told not to publish my research findings,” said Abbott, associate professor of neuroscience at Monash University in Melbourne. “I was shocked. Then it became hard to submit grant applications to continue my research. People would say ‘yes’ to my proposals, then at the last minute, they would back out. If you can’t put a grant in, it could be the end of your research career.” But now Abbott’s efforts have received global recognition – thanks to the judges of the John Maddox prize. Named after the former editor of Nature, and organised by the journal and the charity Sense About Science, the international awards are given to researchers who stand up for sound science. Past winners have included scientists who have been persecuted for speaking out about the dangers of rainforest destruction, the bleaching of coral reefs and the misuse of vitamin C supplements as “treatments” for cancer. This year, US health chief Anthony Fauci and his South African counterpart Salim Abdool Karim were jointly awarded the main John Maddox prize for “communicating the complex science of Covid-19 in the midst of international uncertainty and anxiety”. However, the judges also gave an early career award to Abbott for her perseverance in challenging traditional surgical and stenting procedures as the main way to treat patients at risk of strokes. (A stent is a tiny tube that can be placed into an artery or vein.) © 2020 Guardian News & Media Limited

Keyword: Stroke
Link ID: 27634 - Posted: 12.22.2020

By Isabella Backman Even tough male chimps need their moms. Chimpanzees live in a male-dominated society, where most of their valuable allies are other males. However, as young male chimpanzees become adults, they continue to maintain tight bonds with their mothers, a new study reveals. And for about one-third of them, this mother-son relationship is the closest one they have. The dramatic changes of adolescence are difficult for chimps, just like they are for humans, says Elizabeth Lonsdorf, a primatologist at Franklin & Marshall College who was not involved in the study. And “sure enough,” she says, “their moms remain a key social partner during this turbulent time.” Previous research has shown chimpanzee mothers provide their sons support that goes far beyond nursing. Young male chimps that are close with their moms grow bigger and have a greater chance of survival. What’s more, losing their mothers after weaning, but before age 12, hinders the ability of young chimps to compete with other males and reproduce. To see whether this bond extends later into life, researchers followed 29 adolescent (9 to 15 years old) and young adult (16 to 20 years old) male chimpanzees at a research site in Kibale National Park in Uganda. For 3 years, they observed the chimps from a distance, recording any social interaction they witnessed. These included grooming, comforting behaviors such as holding hands or shoulder pats, looking back for or waiting for other individuals, offering support during conflicts, and sitting near each other. © 2020 American Association for the Advancement of Science.

Keyword: Evolution; Emotions
Link ID: 27633 - Posted: 12.22.2020

by Peter Hess Two types of neurons process social information, a new mouse study suggests, but only one is disrupted in mice missing the autism-linked gene FMR1. The neurons reside in a brain region called the hypothalamus, and both send signals via the hormone oxytocin. The deletion of FMR1, however, affects these cells differently: The loss of FMR1 in the smaller, ‘parvocellular’ neurons diminishes the mice’s interest in social interactions — but only those involving peers, the new work shows. The gene’s loss from the larger, ‘magnocellular’ neurons, by contrast, does not disrupt the animals’ interactions with either peers or parents. “There are a lot of different types of social behaviors, and not all of them are impaired in autism,” says lead investigator Gül Dölen, assistant professor of neuroscience at Johns Hopkins University in Baltimore, Maryland. Whereas peer-to-peer social interactions are troublesome for many autistic people, other social interactions — such as parental connections — are on par with those seen in non-autistic people, she says. This new understanding of the different neurons’ functions could help explain why clinical trials of oxytocin for treating autism traits have shown mixed results. It could also help scientists develop more effective treatments, experts say. “There are these two different kinds of neurons that we’ve known about for a really long time, and each of their contributions to social behavior has never really been dissected out,” says Larry Young, chief of behavioral neuroscience and psychiatric disorders at Emory University in Atlanta, Georgia, who was not involved with the study. “It’s really important for the future of drug development.” © 2020 Simons Foundation

Keyword: Autism; Hormones & Behavior
Link ID: 27632 - Posted: 12.19.2020

By Diana Kwon Seizures are like storms in the brain—sudden bursts of abnormal electrical activity that can cause disturbances in movement, behavior, feelings and awareness. For people with epilepsy, not knowing when their next seizure will hit can be psychologically debilitating. Clinicians have no way of telling people with epilepsy whether a seizure will likely happen five minutes from now, five weeks from now or five months from now, says Vikram Rao, a neurologist at the University of California, San Francisco. “That leaves people in a state of looming uncertainty.” Despite the apparent unpredictability of seizures, they may not actually be random events. Hints of cyclical patterns associated with epilepsy date back to ancient times, when people believed seizures were tied to the waxing and waning of the moon. While this particular link has yet to be definitively proven, scientists have pinpointed patterns in seizure-associated brain activity. Studies have shown that seizures are more likely during specific periods in the day, indicating an association with sleep–wake cycles, or circadian rhythms. In 2018, Rao and his colleagues reported the discovery of long-term seizure-associated brain rhythms—most commonly in the 20- to 30-day range—which they dubbed as “multidien” (multiday) rhythms. By examining these rhythms in brain activity, the group has now demonstrated that seizures can be forecast 24 hours in advance—and in some patients, up to three days prior. Their findings, published December 17 in Lancet Neurology, raise the possibility of eventually providing epilepsy patients with seizure forecasts that could predict the likelihood that a seizure will occur days in advance. © 2020 Scientific American,

Keyword: Epilepsy
Link ID: 27631 - Posted: 12.19.2020

Mercedes Burns An Asian water dragon hatched from an egg at the Smithsonian National Zoo, and her keepers were shocked. Why? Her mother had never been with a male water dragon. Through genetic testing, zoo scientists discovered the newly hatched female, born on Aug. 24, 2016, had been produced through a reproductive mode called parthenogenesis. Parthenogenesis is a Greek word meaning “virgin creation,” but specifically refers to female asexual reproduction. While many people may assume this behavior is the domain of science fiction or religious texts, parthenogenesis is surprisingly common throughout the tree of life and is found in a variety of organisms, including plants, insects, fish, reptiles and even birds. Because mammals, including human beings, require certain genes to come from sperm, mammals are incapable of parthenogenesis. Creating offspring without sperm Sexual reproduction involves a female and a male, each contributing genetic material in the form of eggs or sperm, to create a unique offspring. The vast majority of animal species reproduce sexually, but females of some species are able to produce eggs containing all the genetic material required for reproduction. Females of these species, which include some wasps, crustaceans and lizards, reproduce only through parthenogenesis and are called obligate parthenogens. A larger number of species experience spontaneous parthenogenesis, best documented in animals kept in zoo settings, like the Asian water dragon at the National Zoo or a blacktip shark at the Virginia Aquarium. Spontaneous parthenogens typically reproduce sexually, but may have occasional cycles that produce developmentally ready eggs. © 2010–2020, The Conversation US, Inc.

Keyword: Sexual Behavior
Link ID: 27630 - Posted: 12.19.2020

By Bruce Bower Bonobos display responsibility toward grooming partners akin to that of people working together on a task, a new study suggests. Until now, investigations have shown only that humans can work jointly toward a common goal presumed to require back-and-forth exchanges and an appreciation of being obligated to a partner (SN: 10/5/09). Primate biologist Raphaela Heesen of Durham University in England and colleagues studied 15 of the endangered great apes at a French zoological park. The researchers interrupted 85 instances of social grooming, in which one ape cleaned another’s fur, and 26 instances of self-grooming or solitary play. Interruptions consisted either of a keeper calling one bonobo in a grooming pair to come over for a food reward or a keeper rapidly opening and closing a sliding door to an indoor enclosure, which typically signaled mealtime and thus attracted both bonobos. Social grooming resumed, on average, 80 percent of the time after food rewards and 83 percent of the time after sliding-door disruptions, the researchers report December 18 in Science Advances. In contrast, self-grooming or playing alone was resumed only around 50 percent of the time, on average. © Society for Science & the Public 2000–2020

Keyword: Evolution; Emotions
Link ID: 27629 - Posted: 12.19.2020

By Matthew Hutson Somehow, even in a room full of loud conversations, our brains can focus on a single voice in something called the cocktail party effect. But the louder it gets—or the older you are—the harder it is to do. Now, researchers may have figured out how to fix that—with a machine learning technique called the cone of silence. Computer scientists trained a neural network, which roughly mimics the brain’s wiring, to locate and separate the voices of several people speaking in a room. The network did so in part by measuring how long it took for the sounds to hit a cluster of microphones in the room’s center. When the researchers tested their setup with extremely loud background noise, they found that the cone of silence located two voices to within 3.7º of their sources, they reported this month at the online-only Conference on Neural Information Processing Systems. That compares with a sensitivity of only 11.5º for the previous state-of-the-art technology. When the researchers trained their new system on additional voices, it managed the same trick with eight voices—to a sensitivity of 6.3º—even if it had never heard more than four at once. Such a system could one day be used in hearing aids, surveillance setups, speakerphones, or laptops. The new technology, which can also track moving voices, might even make your Zoom calls easier, by separating out and silencing background noise, from vacuum cleaners to rambunctious children. © 2020 American Association for the Advancement of Science.

Keyword: Hearing
Link ID: 27628 - Posted: 12.19.2020

Sophie Balisky, 26, says she struggled with anorexia and bulimia through most of her teens but got help three years ago and was doing great — until COVID hit and she lost her job as a flight attendant. She found herself reverting to old coping patterns in dealing with stressful and uncertain situations. "I was actually quite shocked, I was a bit taken aback, because I consider myself to be quite strong in my coping against my eating tendencies," said Balisky. Advocates for those who struggle with eating disorders say the pandemic is exacerbating the problem — prompting a greater need for community supports. Experts believe the problem is related to the stress, uncertainty and isolation that stems from the pandemic and related-restrictions and say it's not only a problem in the province but around the world. Some eating disorder support groups in Alberta who connect with people of all ages say they have seen a steady rise in demand since the pandemic hit. The Eating Disorder Support Network of Alberta is reporting a 5½ times increase in participants year-over-year between the period from March to the end of August. "So a huge surge through this," said Lauren Berlinguette, executive director of the support network. Another community-based agency that offers support to those who are struggling as well as their families, the Calgary Silver Linings Foundation, says it's experiencing a substantial increase in demand, too. The number of participants in all of its adult programs went from 37 to 64 participants, year-over-year. ©2020 CBC/Radio-Canada.

Keyword: Anorexia & Bulimia
Link ID: 27627 - Posted: 12.15.2020

By Paula Span By now, we were supposed to be swiftly approaching the day when we could walk into a CVS or Walgreens, a Best Buy or Walmart, and walk out with a pair of quality, affordable hearing aids approved by the Food and Drug Administration. Hearing aids, a widely needed but dauntingly expensive investment, cost on average $4,700 a pair. (Most people need two.) So in 2017, Congress passed legislation allowing the devices to be sold directly to consumers, without a prescription from an audiologist. The next step was for the F.D.A. to issue draft regulations to establish safety and effectiveness benchmarks for these over-the-counter devices. Its deadline: August 2020. A public comment period would follow, and then — right about now — the agency would be preparing its final rule, to take effect in May 2021. So by next summer, people with what is known as “perceived mild to moderate hearing loss” might need to spend only one-quarter of today’s price or less, maybe far less. And then we could have turned down the TV volume and stopped making dinner reservations for 5:30 p.m., when restaurants are mostly empty and conversations are still audible. “These regulations are going to help a lot of people,” said Dr. Vinay Rathi, an otolaryngologist at Massachusetts Eye and Ear. “There could be great potential for innovation.” So, where are the new rules? This long-sought alternative to the current state of hearing aid services has been delayed, perhaps one more victim of the pandemic. Of course, the agency has other crucial matters to address just now. Although the office charged with hearing aid regulations is not the one assessing Covid-19 vaccines, an F.D.A. spokesman said via email that it was dealing with “an unprecedented volume of emergency use authorizations” for diagnostics, ventilators and personal protective equipment. © 2020 The New York Times Company

Keyword: Hearing
Link ID: 27626 - Posted: 12.15.2020

Claudia Dreifus Questions like “why do men and women act differently?” are age-old, with tangled, deeply buried answers. But that is why Catherine Dulac, a Howard Hughes Medical Investigator and a professor of molecular and cellular biology at Harvard University, has become so well respected by her neuroscientist colleagues for the originality and creativity with which she has brought important answers to light. Though she is trained as a developmental biologist, Dulac takes her research into territory usually explored by social scientists by trying to discern the balance of genetic determination and environmental influence that shapes vital behaviors in mammals. Moreover, she deploys the genetic tools of modern biology to discover the mechanisms that activate these behaviors. Relatively early in her career, Dulac’s investigations into how animals detect pheromones changed our understanding of what those airborne chemicals may signify to the brain. More recently, her experiments identified how the brain circuitry that regulates crucial mating and parenting behaviors works — at least in her model animals, which are mice. She found astonishing evidence that although certain of these behaviors are often described as “male” or “female,” both types of circuitry are present and potentially active in both sexes. As a result, the right combination of triggers can switch an individual creature’s behavior to that of the opposite sex. Scientists are still exploring the full implications of her findings, but Dulac and others are hopeful that they might yield useful insights into conditions like postpartum behavioral disorders. Because of her work’s relevance, in September Dulac, just age 57, was awarded the $3 million Breakthrough Prize in Life Sciences, the richest single personal award in the scientific world. The citation for the prize hailed the success of her work, which connected behaviors to specific neural mechanisms and “overturned decades-old dogma in behavioral science.” Simons Foundation © 2020

Keyword: Sexual Behavior
Link ID: 27625 - Posted: 12.15.2020

By Cara Giaimo The rooms that make up the Bloomington Drosophila Stock Center at Indiana University are lined wall to wall with identical shelves. Each shelf is filled with uniform racks, and each rack with indistinguishable glass vials. The tens of thousands of fruit fly types within the vials, though, are each magnificently different. Some have eyes that fluoresce pink. Some jump when you shine a red light on them. Some have short bodies and iridescent curly wings, and look “like little ballerinas,” said Carol Sylvester, who helps care for them. Each variety doubles as a unique research tool, and it has taken decades to introduce the traits that make them useful. If left unattended, the flies would die in a matter of weeks, marooning entire scientific disciplines. Throughout the Covid-19 pandemic, workers across industries have held the world together, taking on great personal risk to care for sick patients, maintain supply chains and keep people fed. But other essential jobs are less well-known. At the Stock Center dozens of employees have come to work each day, through a lockdown and afterward, to minister to the flies that underpin scientific research. Tiny Bug, Huge Impact To most casual observers, fruit flies are little dots with wings that hang out near old bananas. But over the course of the last century, researchers have turned the insect — known to science as Drosophila melanogaster — into a sort of genetic switchboard. Biologists regularly develop new “strains” of flies, in which particular genes are turned on or off. Studying these slight mutants can reveal how those genes function — including in humans, because we share over half of our genes with Drosophila. For instance, researchers discovered what is now called the hippo gene — which helps regulate organ size in both fruit flies and vertebrates — after flies with a defect in it grew up to be unusually large and wrinkly. Further work with the gene has indicated that such defects may contribute to the unchecked cell growth that leads to cancer in people. © 2020 The New York Times Company

Keyword: Genes & Behavior; Development of the Brain
Link ID: 27624 - Posted: 12.15.2020

By Krystnell A. Storr Can you tell the difference between high – and low –thread-count sheets just by touching them? Thank usherin, a protein found in a mysterious structure in your fingertips. Usherin also helps us see and hear, suggesting a deep molecular connection among our most important senses. “The work is surprising,” says Ellen Lumpkin, a neuroscientist at the University of California (UC), Berkeley, who was not involved in the study. The study, she says, points to a single protein being used over and over again in distinct ways to help us monitor the outside world. Scientists already had some hints that usherin is important for our sense of touch. A mutation in the gene that codes for it, USH2A, causes Usher syndrome—a rare, inherited disease that leads to blindness, deafness, and an inability to feel faint vibrations in the fingertips. To further explore usherin’s role in touch, researchers recruited 13 patients with a form of Usher syndrome that specifically affects touch. The team—led by Gary Lewin, a neuroscientist at the Max Delbrück Center for Molecular Medicine—measured how well each person sensed pain, temperature changes, and tiny vibrations at 10 and 125 hertz (Hz), mimicking the sensation of moving a fingertip across a rough surface. The scientists then compared the patients’ results against those of 65 healthy volunteers. People with Usher syndrome did just as well as their counterparts at sensing temperature changes and mild pain, the team found. But they were four times less likely to pick up on the 125-Hz vibrations and 1.5 times less likely to detect the 10-Hz vibrations. © 2020 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 27623 - Posted: 12.12.2020

Sam Wollaston A single-storey building in a lonely rural business park, a few miles from Milton Keynes on a grey autumn day. It looks like a location for a bleak thriller: where a kidnap victim is held, perhaps, or the scene of a final shootout. Inside, though, something kind of cool is happening. In a brightly lit room, four inverted metal cups have been placed on the red carpet, each containing a small glass jar. One of these contains a smell: a “training odour”. Into the room bursts Billy, followed by Jess. Billy is a labrador, and Jess his human trainer. Billy bounces about the place, clearly super excited. He sniffs at everything – furniture, people, the cups – wagging ferociously. When he sniffs at the cup that contains the smell, another trainer, Jayde, indicates success with a clicking noise. Billy is rewarded with his favourite toy, a well-chewed rubber ball, and a chorus of “good boy”. So far, so unremarkable. Dogs have excellent noses, everyone knows that. They are estimated to be at least 10,000 times better than ours. It’s not immediately clear just how good Billy is. Did he really find the smell, or did Jayde just click when he sniffed the right cup? To be fair to Billy, he’s young, 18 months old, and this is only his second session. The trainers – Jess, Jayde and Mark – have high hopes for him. And after a couple more goes, it becomes clear that he is definitely finding the right cup, quickly. He is also clearly enjoying the game. What Billy lacks in refinement, he makes up for in youthful enthusiasm and exuberance, and he learns fast. Which is good news: this is just the first stage for Billy, who is on a fast-track training course to learn to sniff out Covid-19. He’s not working with the actual virus, of course, but a training sample, which will teach him to do that job. © 2020 Guardian News & Media Limited

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27622 - Posted: 12.12.2020

Jon Hamilton Root extracts from the African shrub iboga have long been used in traditional healing rituals and more recently as an experimental treatment for depression and to reduce drug cravings in addiction. Scientists now are working on a version of the extract that doesn't cause heart attacks or hallucinations as side effects. Steeve Jordan/AFP via Getty Images A chemically tweaked version of the psychedelic drug ibogaine appears to relieve depression and addiction symptoms without producing hallucinations or other dangerous side effects. The results of a study in rodents suggest it may be possible to make psychedelic drugs safe enough to become mainstream treatments for psychiatric disorders, the authors report Wednesday in the journal Nature. "What we need is a medicine that is so safe that you can take it home and put it in your medicine cabinet just like you would aspirin," says David Olson, the paper's senior author and an assistant professor at the University of California, Davis. "And that's really what we were trying to achieve." The success with ibogaine is "a promising first step," says Gabriela Manzano, a postdoctoral fellow at Weill Cornell Medicine in New York and a co-author of a commentary on the study. "This provides a road map on how we could start tweaking these chemical compounds to make them very useful in the clinic," she says. "Keep the good parts, get rid of the bad parts." For decades, psychedelic drugs, including ketamine and psilocybin, have shown promise in treating people with mental health problems including addiction, depression and post-traumatic stress disorder. But doctors and researchers have been wary of using the drugs because of their side effects. © 2020 npr

Keyword: Drug Abuse; Depression
Link ID: 27621 - Posted: 12.12.2020

By Jennie Erin Smith MEDELLÍN, Colombia — Aliria Rosa Piedrahita de Villegas carried a rare genetic mutation that had all but guaranteed she would develop Alzheimer’s disease in her 40s. But only at age 72 did she experience the first symptoms of it. Her dementia was not terribly advanced when she died from cancer on Nov. 10, a month shy of her 78th birthday, in her daughter’s home on a hillside that overlooks the city. Neurology investigators at the University of Antioquia in Medellín, led by Dr. Francisco Lopera, have followed members of Ms. Piedrahita de Villegas’s vast extended family for more than 30 years, hoping to unlock the secrets of early-onset Alzheimer’s disease. In that time they encountered several outliers, people whose disease developed later than expected, in their 50s or even 60s. But none were as medically remarkable as the woman they all knew as doña Aliria. In recent years Aliria traveled to Boston, where investigators at Massachusetts General Hospital conducted nuclear imaging studies of her brain as part of an ongoing study of this Colombian family, the largest in the world with genetic early-onset Alzheimer’s. In Boston it was discovered that Aliria had exceptionally large quantities of one protein seen in Alzheimer’s — amyloid beta — without much tau, the toxic protein that spreads later in the disease cascade. Something had interrupted the usual degenerative process, leaving her day-to-day functioning relatively preserved. Last year, researchers at Harvard Medical School and the University of Antioquia published the surprise finding that while Aliria carried a well-known mutation, unique to Colombia, that causes early Alzheimer’s, she also carried two copies of another rare mutation that appear to have thwarted the activity of the first one. Since then, investigators worldwide have been studying what is known as the Christchurch mutation, a variant on a gene, APOE, that can affect a person’s risk of developing Alzheimer’s. Thus far, drugs targeting amyloid beta have disappointed in clinical trials. If the protective effect of Aliria’s double Christchurch mutation can be replicated, a new avenue for desperately needed therapies could open. © 2020 The New York Times Company

Keyword: Alzheimers; Genes & Behavior
Link ID: 27620 - Posted: 12.12.2020

By Jason Castro To be an expectant mother, or the anxious partner of one, is to be keenly, even agonizingly aware of how chemicals affect a developing life. The basic advice is well known, and obsessively followed: Alcohol in strict moderation, and no nicotine at all. Don’t mess with mercury. Folic acid is your friend. More protein and less caffeine. Stay away from BPA, PBCs and PFA, and generally make an enemy of the unpronounceable. But, if we take the results of a provocative recent paper seriously, there may be another important, and deeply underappreciated chemical influence at work: a man’s odor. The research, by a team headed by Noam Sobel of the Weizmann Institute of Science, suggests that there is a relationship between women’s response to “social odors” contained in male sweat and the heartbreaking condition of unexplained repeated pregnancy loss (uRPL). Specifically, in blind smell-tests, these scientists observed that women who had experienced uRPL were significantly better at identifying their spouse’s odor than age-matched controls. Additionally, their brains responded differently to nonspouse odors and they displayed unique olfactory neuroanatomy. Taken in the context of a large body of literature on chemosignaling in nonhuman animals, these results make it conceivable that the human nose could also communicate with the womb and may even influence a pregnancy. So far, the results are strictly correlative, and in no way point to male odor as some kind of pheromonal smoking gun that explains pregnancy loss. Hypothetically, it could also be true that women experiencing uRPL have, on average, larger middle toes, larger whites of their eyes, thinner wrists and a proclivity for wearing purple socks. None of these would give one pause or prompt a serious search for some kind of causal link to pregnancy loss. Yet this particular link between smell and pregnancy loss is intriguing because of how prevalent and robust it is in other mammals, including primates. Many miscarriages still have unexplained causes, which makes any lead, correlative or not, a particularly interesting and worthwhile area of research. © 2020 Scientific American

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 27619 - Posted: 12.09.2020

David Cox Seven years ago, rhinology surgeon Peter Andrews found himself performing an operation that would go on to change the course of his career. Andrews was operating on a patient who had broken his nose many decades earlier after being struck by a cricket ball. The procedure was delicate: straightening the septum – the thin wall of cartilage that separates the nostrils – and in the process improving his breathing, which had become more laboured in later life. But it had a surprising outcome. As well being able to breathe more freely, Andrews’s patient found he could smell again for the first time in 40 years, a remarkable turn of events that provided the medical community with a new insight into our sense of smell, and its capacity to regenerate. Being able to smell is actually a result of a complex neurological process. Smell-specific nerve cells known as olfactory neurons, located high in the nasal cavity, detect molecules in the air such as those released by a perfume, or smoke particles from something burning. They then convey this information via a long nerve fibre running up through the skull, to a part of the brain that makes sense of it all. This network is one of the most adaptable in the entire central nervous system. To keep functioning, it completely regenerates every six weeks, shedding existing olfactory neurons, and creating new ones from scratch. “That’s quite a feat in itself, because those neurons then have to reconnect up into the brain tissue,” says Andrews. But sometimes things can happen that impair its ability to regenerate. An estimated 5% of the general population is believed to have anosmia, the medical term for temporary or permanent smell loss. Anosmia can occur as part of the ageing process, but also in those of all ages due to factors ranging from broken noses to viral infections. © 2020 Guardian News & Media Limited

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27618 - Posted: 12.09.2020