Susan Milius Cheating pays, sort of. But for a glossy blue-black bird with a bright yellow eye, cheating doesn’t outdo regular honest parenting. The greater ani, a type of cuckoo found from Panama to the Amazon Basin, usually starts out as a dutiful parent. Two or three male-female pairs typically build and fill a communal nest “like a big basket of eggs,” says behavioral ecologist Christina Riehl of Princeton University. But if a snake or some other disaster kills the young, a bereft female sometimes gets sneaky. She slips into neighboring ani nests and leaves an egg here and there that she won’t care for, but the rightful nest owners might. Not all females from trashed nests do that. Some just wait for the next breeding season, when all the birds get a fresh start building another nest. Greater anis’ sporadic cheating offers a rare chance to compare the success of egg-sneaks with honest mothers in the same species. Over 11 breeding seasons, Riehl and colleagues determined the parentage of more than 1,700 eggs and found 65 eggs in foster nests. Mothers that parasitize other nests in this way seem to lay more eggs a year, on average, Riehl says. “It’s actually kind of hard to be a parasite,” she says. But the average number of chicks that survived to flutter out of the nest on their own frantic wing power was about the same for all females, Riehl and Princeton colleague Meghan Strong report online February 27 in Nature. The mothers that always cooperated averaged about one fledgling a year, and so did the females that laid stealth eggs. |© Society for Science & the Public 2000 - 2019

Keyword: Sexual Behavior; Evolution
Link ID: 25991 - Posted: 02.28.2019

By Karen Weintraub All serious butterfly collectors remember their first gynandromorph: a butterfly with a color and pattern that are distinctly male on one wing and female on the other. Seeing one sparks wonder and curiosity. For the biologist Nipam H. Patel, the sighting offered a possible answer to a question he had been pondering for years: During embryonic and larval development, how do cells know where to stop and where to go? He was sure that the delicate black outlines between male and female regions appearing on one wing — but not the other — identified a key facet of animal development. “It immediately struck me that this was telling me something interesting about how the wing was being made,” said Dr. Patel, a biologist who now heads the Marine Biological Laboratory, a research institute in Woods Hole, Mass., affiliated with the University of Chicago. The patterning on the gynandromorph’s wing shows that the body uses signaling centers to control where cells go during development and what tissues they become in creatures as diverse as butterflies and people, Dr. Patel said. Gynandromorph butterflies and other half-male, half-female creatures, particularly birds, have fascinated both scientists and amateurs for centuries. The latest sensation was a half-red, half-taupe cardinal that became a regular visitor in the backyard of Shirley and Jeffrey Caldwell in Erie, Pa. Although the bird would have to be tested to confirm that it is a gynandromorph, its color division strongly suggests that it is, scientists say. Split-sex creatures are not as unusual as they may seem when one discovery goes viral, as the cardinal’s did. It extends beyond birds and butterflies to other insects and crustaceans, like lobsters and crabs. © 2019 The New York Times Company

Keyword: Sexual Behavior
Link ID: 25990 - Posted: 02.27.2019

By Alex Therrien Health reporter, BBC News A radical Parkinson's treatment that delivers a drug directly to the brain has been tested in people. Patients in the trial were either given the drug, which is administered via a "port" in the side of the head, or a dummy treatment (placebo). Both groups showed improved symptoms, meaning it was not clear if the drug was responsible for the benefits. However, scans did find visual evidence of improvements to affected areas of the brain in those given the drug. The study's authors say it hints at the possibility of "reawakening" brain cells damaged by the condition. Other experts, though, say it is too early to know whether this finding might result in improvements in Parkinson's symptoms. Researchers believe the port implant could also be used to administer chemotherapy to those with brain tumours or to test new drugs for Alzheimer's and stroke patients. Parkinson's causes parts of the brain to become progressively damaged, resulting in a range of symptoms, such as involuntary shaking and stiff, inflexible muscles. About 145,000 people a year in the UK are diagnosed with the degenerative condition, which cannot be slowed down or reversed. For this new study, scientists gave patients an experimental treatment called glial cell line-derived neurotrophic factor (GDNF), in the hope it could regenerate dying brain cells and even reverse the condition. © 2019 BBC.

Keyword: Parkinsons; Trophic Factors
Link ID: 25989 - Posted: 02.27.2019

By Roni Caryn Rabin Cannabidiol, or CBD, a nonintoxicating component of the marijuana plant, is touted as a magic bullet that eases pain, anxiety, insomnia and depression. Salves, sprays, tinctures and oils containing CBD are marketed as aphrodisiacs that boost desire; as balms for eczema, pimples and hot flashes; and even as treatments for serious diseases like diabetes and multiple sclerosis. Unlike THC, or tetrahydrocannabinol, the “psychoactive” component of the cannabis plant, CBD won’t get you “high.” But scientists know little about what it can do: Most of the information about CBD’s effects in humans is anecdotal or extrapolated from animal studies, and few rigorous trials have been conducted. “It is a kind of a new snake oil in the sense that there are a lot of claims and not so much evidence,” said Dustin Lee, an assistant professor in psychiatry and behavioral sciences at Johns Hopkins University who is planning a human trial of CBD for use in quitting smoking. The Food and Drug Administration has approved some drugs made from synthetic substances similar to THC to treat poor appetite and nausea in people with A.I.D.S. or cancer. But so far, the F.D.A. has approved only one drug containing CBD, Epidiolex, after clinical trials found it reduced seizures in children with two rare, severe forms of epilepsy. “There’s a lot of hype about everything about CBD,” said Dr. Orrin Devinsky, the director of the NYU Langone Comprehensive Epilepsy Center, who led the Epidiolex studies and went out of his way to say the drug’s effect was “not miraculous.” “There is certainly data that it has a variety of anti-inflammatory effects, but whether that translates into improving human health is unknown. Does it help people with eczema, rheumatoid arthritis or ulcerative colitis? We don’t know. There is a good theoretical basis, but the studies have not been done.” © 2019 The New York Times Company

Keyword: Drug Abuse; Sleep
Link ID: 25988 - Posted: 02.27.2019

By Achim Peters Although our brain accounts for just 2 percent of our body weight, the organ consumes half of our daily carbohydrate requirements—and glucose is its most important fuel. Under acute stress the brain requires some 12 percent more energy, leading many to reach for sugary snacks. Carbohydrates provide the body with the quickest source of energy. In fact, in cognitive tests subjects who were stressed performed poorly prior to eating. Their performance, however, went back to normal after consuming food. When we are hungry, a whole network of brain regions activates. At the center are the ventromedial hypothalamus (VMH) and the lateral hypothalamus. These two regions in the upper brain stem are involved in regulating metabolism, feeding behavior and digestive functions. There is, however, an upstream gatekeeper, the nucleus arcuatus (ARH) in the hypothalamus. If it registers that the brain itself lacks glucose, this gatekeeper blocks information from the rest of the body. That’s why we resort to carbohydrates as soon as the brain indicates a need for energy, even if the rest of the body is well supplied. To further understand the relationship between the brain and carbohydrates, we examined 40 subjects over two sessions. In one, we asked study participants to give a 10-minute speech in front of strangers. In the other session they were not required to give a speech. At the end of each session, we measured the concentrations of stress hormones cortisol and adrenaline in participants’ blood. We also provided them with a food buffet for an hour. When the participants gave a speech before the buffet, they were more stressed, and on average consumed an additional 34 grams of carbohydrates, than when they did not give a speech. © 2019 Scientific American

Keyword: Stress; Obesity
Link ID: 25987 - Posted: 02.27.2019

By Michael Price Insomnia, often blamed on stress or bad sleep habits, may instead be closely linked to depression, heart disease, and other physiological disorders, a pair of deep dives into the human genome now reveals. “Both studies are very well done,” says psychologist Philip Gehrman of the University of Pennsylvania’s Perelman School of Medicine, who researches sleep behavior. Still, he stresses, much more work remains before the genetic connections to insomnia can be translated to new therapies for patients. Insomnia costs the U.S. workforce more than $63 billion each year in lost productivity, according to some estimates. It’s also incredibly common: As much as a third of the worldwide population suffers from insomnia-related symptoms at any given time. Yet the disorder remains poorly understood. In one new paper reported today in Nature Genetics, researchers led by geneticist Danielle Posthuma of Vrije Universiteit in Amsterdam conducted a genome-wide association study (GWAS), which looks for links between shared sequences of DNA and particular behaviors or clinical symptoms. The group analyzed the genomes of more than 1 million people, which the authors say is the largest GWAS to date. The data came from UK Biobank, a long-running, enormous U.K. genetics study, and the private genetics firm 23andMe. The prevalence of insomnia in the people covered by both databases was about 30%, which is in line with estimates for the general population. © 2019 American Association for the Advancement of Science

Keyword: Sleep; Depression
Link ID: 25986 - Posted: 02.26.2019

By Tom Avril Smoking cigarettes has long been known for its ability to damage eyesight, on top of the harm it causes to the lungs, heart and other organs. But a new study suggests that smoking can impair vision far earlier than is commonly thought. Heavy smokers with an average age of 35 were markedly worse than nonsmokers at distinguishing colors as well as the contrast between different shades of gray, the study authors said. Previous research has linked smoking with macular degeneration and cataracts, which tend to occur decades later. The new results, published in Psychiatry Research, do not indicate how smoking damages perception of color and contrast. But the broad nature of the impairment suggests that it is not the result of damage to specific kinds of light-sensitive cells, such as rods or cones, said co-author Steven Silverstein, a professor of psychiatry and ophthalmology at Rutgers Robert Wood Johnson Medical School. Instead, cigarette use probably harms a more general aspect of vision biology, such as blood vessels or nerve cells. “There is probably some more widespread problem like overall blood flow in the eye that is compromised due to all the toxic chemicals in cigarettes,” said Silverstein, who collaborated with authors from the Perception, Neuroscience and Behavior Laboratory in Joao Pessoa, Brazil. © 1996-2019 The Washington Post

Keyword: Drug Abuse; Vision
Link ID: 25985 - Posted: 02.26.2019

Jonathan Lambert The experience of natural spaces, brimming with greenish light, the smells of soil and the quiet fluttering of leaves in the breeze can calm our frenetic modern lives. It's as though our very cells can exhale when surrounded by nature, relaxing our bodies and minds. Some people seek to maximize the purported therapeutic effects of contact with the unbuilt environment by embarking on sessions of forest bathing, slowing down and becoming mindfully immersed in nature. But in a rapidly urbanizing world, green spaces are shrinking as our cities grow out and up. Scientists are working to understand how green spaces, or lack of them, can affect our mental health. A study published Monday in the journal PNAS details what the scientists say is the largest investigation of the association between green spaces and mental health. Researchers from Aarhus University in Denmark found that growing up near vegetation is associated with an up to 55 percent lower risk of mental health disorders in adulthood. Kristine Engemann, the biologist who led the study, combined decades of satellite imagery with extensive health and demographic data of the Danish population to investigate the mental health effects of growing up near greenery. "The scale of this study is quite something," says Kelly Lambert, a neuroscientist at the University of Richmond who studies the psychological effects of natural spaces. Smaller studies have hinted that lack of green space increases the risk of mood disorders and schizophrenia and can even affect cognitive development. © 2019 npr

Keyword: Depression; Development of the Brain
Link ID: 25984 - Posted: 02.26.2019

Genevieve Fox You receive an invitation, emblazoned with a question: “A bouncing little ‘he’ or a pretty little ‘she’?” The question is your teaser for the “gender reveal party” to which you are being invited by an expectant mother who, at more than 20 weeks into her pregnancy, knows what you don’t: the sex of her child. After you arrive, explains cognitive neuroscientist Gina Rippon in her riveting new book, The Gendered Brain, the big reveal will be hidden within some novelty item, such as a white iced cake, and will be colour-coded. Cut the cake and you’ll see either blue or pink filling. If it is blue, it is a… Yes, you’ve guessed it. Whatever its sex, this baby’s future is predetermined by the entrenched belief that males and females do all kinds of things differently, better or worse, because they have different brains. A neuroscientist explains: the need for ‘empathetic citizens’ - podcast “Hang on a minute!” chuckles Rippon, who has been interested in the human brain since childhood, “the science has moved on. We’re in the 21st century now!” Her measured delivery is at odds with the image created by her detractors, who decry her as a “neuronazi” and a “grumpy old harridan” with an “equality fetish”. For my part, I was braced for an encounter with an egghead, who would talk at me and over me. Rippon is patient, though there is an urgency in her voice as she explains how vital it is, how life-changing, that we finally unpack – and discard – the sexist stereotypes and binary coding that limit and harm us. For Rippon, a twin, the effects of stereotyping kicked in early. Her “under-achieving” brother was sent to a boys’ academic Catholic boarding school, aged 11. “It’s difficult to say this. I was clearly academically bright. I was top in the country for the 11+.” This gave her a scholarship to a grammar school. Her parents sent her to a girls’ non-academic Catholic convent instead. © 2019 Guardian News & Media Limited

Keyword: Sexual Behavior
Link ID: 25983 - Posted: 02.26.2019

Erin Wayman During the last few weeks of her life, Mama, an elderly chimpanzee at a zoo in the Netherlands, received a special visitor. As Mama lay curled up on a mound of straw, biologist Jan van Hooff entered her enclosure. Van Hooff, who had known Mama for more than 40 years, knelt down and stroked the arm of the listless chimp. When Mama looked up, her vacant face erupted into a smile. She reached out to van Hooff, calling out as she patted his face and neck. For primatologist Frans de Waal, this touching scene isn’t difficult to interpret: Mama was happy to see her old friend. But such an interpretation has been taboo among many behavioral scientists, who have claimed nonhuman animals are like unthinking, emotionless machines that react to situations with preprogrammed instincts. In the thought-provoking Mama’s Last Hug, de Waal dismantles that view. He presents piles of evidence that animals are emotional beings. The book is a companion to Are We Smart Enough to Know How Smart Animals Are?, in which he explored animal intelligence (SN: 12/24/16 & 1/7/17, p. 40). Emotions, de Waal writes, “are bodily and mental states — from anger and fear to sexual desire and affection and seeking the upper hand — that drive behavior.” On page after page, he tells of depressed fish, empathetic rats, envious monkeys and other emotional creatures. More than a collection of fascinating anecdotes, Mama’s Last Hug weaves together formal observations of animals in the wild and in captivity, behavioral experiments and neuroscience research. |© Society for Science & the Public 2000 - 2019.

Keyword: Emotions; Evolution
Link ID: 25982 - Posted: 02.26.2019

By Karen Weintraub A widely criticized experiment last year saw a researcher in China delete a gene in twin girls at the embryonic stage in an attempt to protect them from HIV. A new study suggests that using a drug to delete the same gene in people with stroke or traumatic brain injuries could help improve their recovery. The new work shows the benefits of turning off the gene in stroke-induced mice by using the drug, already approved as an HIV treatment. It also focuses on a sample of people who were naturally born without the gene. People without the gene recover faster and more completely from stroke than the general population does, the researchers found. The combined results suggest the drug might boost recovery in humans after a stroke or traumatic brain injury, says S. Thomas Carmichael, the study’s senior researcher and a neurologist at the University of California, Los Angeles, David Geffen School of Medicine. His team has started a follow-up human study to test the drug’s efficacy. The combination of mouse research and leveraging of people’s genetic data to confirm the relevance of drug targets makes the new research a “landmark paper,” says Jin-Moo Lee, co-director of the Barnes–Jewish Hospital and Washington University Stroke and Cerebrovascular Center in Saint Louis who was not involved with the work. © 2019 Scientific American

Keyword: Stroke
Link ID: 25981 - Posted: 02.22.2019

By Roni Caryn Rabin Q. Is there a purpose to a yawn? I know it means you’re sleepy, but is the body trying to accomplish something by the act of yawning? A. People yawn when they’re tired, but also when they wake from a night’s sleep. We yawn when we’re bored, but also when we’re anxious, or hungry, or about to start a new activity. Yawning is contagious — we often start yawning the minute someone near us starts. “There are so many triggers. People who sky-dive say they tend to yawn before jumping. Police officers say they yawn before they enter a difficult situation,” said Adrian Guggisberg, a professor of clinical neuroscience at the University of Geneva. Reading about yawning makes people yawn. You are probably yawning right now. But the physiological purpose of a yawn remains a mystery. “The real answer so far is we don’t really know why we yawn,” Dr. Guggisberg said. “No physiological effect of yawning has been observed so far, and that’s why we speculate. It’s possible yawning doesn’t really have a physiological effect.” Until about 30 years ago, scientists explained yawning as a way for the body to take in a large amount of air in order to increase oxygen levels in the blood in response to oxygen deprivation. But the oxygenation hypothesis was discarded after being disproved by a series of experiments published in 1987. One current theory is that yawning is a brain cooling mechanism “that functions to promote arousal and alertness,” according to Andrew Gallup, an assistant professor of psychology at the State University of New York Polytechnic Institute in Utica, who has published studies on the topic. © 2019 The New York Times Company

Keyword: Emotions
Link ID: 25980 - Posted: 02.22.2019

Nicole Creanza and Kate Snyder How do individuals choose their mates? Why are some more successful at attracting mates than others? These age-old questions are broadly relevant to all animals, including human beings. Darwin’s theory of natural selection offers one way to answer them. Sometimes phrased as “survival of the fittest,” the theory can also apply to mate choice, predicting that it’s beneficial to choose the mate who’s best adapted to surviving in its environment — the fastest runner, the best hunter, the farmer with the highest yields. That’s a bit simplistic as a summary of human sexuality, of course, since people pair up in the context of complex social norms and gender roles that are uniquely human. Researchers like us do think, though, that mate choice in other animals is influenced by these kinds of perceived adaptations. It fits with scientists’ understanding of evolution: If females choose to mate with well-adapted males, their offspring might have a better chance of surviving as well. Advantageous traits wind up passed down and preserved in future generations. But in many species, males try to attract mates by displaying characteristics that seem to be decidedly non-adaptive. These signals – such as a dazzling tail on a peacock or a beautiful tune from a songbird – were originally a big wrench thrown into Darwin’s theory of natural selection. Traits like these seem to do the opposite of making an animal more likely to survive in its environment. A flashy tail display or a showy melody is cumbersome, and it announces you to predators as well as love interests. Darwin got so upset by this inconsistency that he said “The sight of a feather in a peacock’s tail, whenever I gaze at it, makes me sick.” © 2010–2019, The Conversation US, Inc.

Keyword: Sexual Behavior; Evolution
Link ID: 25979 - Posted: 02.22.2019

By Veronique Greenwood Sleep — that absurd, amazing habit of losing consciousness for hours on end — is so universal across the animal kingdom that we usually assume it is essential to survival. Now, however, scientists who repeatedly disturbed the sleep of more than a thousand fruit flies are reporting that less slumber may be necessary for sustaining life than previously thought, at least in one species. A handful of studies involving dogs and cockroaches going back to the late 19th century suggest that being deprived of sleep can result in a shortened life span. But the methods behind some of these studies can make it difficult to say whether the test subjects were harmed by sleep deprivation itself, or by the stress of the treatment they were given — such as being shaken constantly. The new study took a milder approach, in hope of seeing the true effects of sleep deprivation. The automated system the researchers developed for monitoring the flies kept track of their movements with cameras, scoring any extended period without movement as sleep. When they were not being awakened repeatedly, the males slept about 10 hours a day, females about five on average. To keep the flies awake, the researchers equipped the system with tiny motors that would gently tip the flies any time they went still for at least 20 seconds. With this method, researchers deprived flies of rest over the course of their entire lifetimes, tipping them hundreds of times a day such that if they were snoozing during those periods of stillness, they might have been able to sleep around 2.5 hours a day on average. “When the results came from that experiment, it was very surprising,” said Giorgio Gilestro, a professor at Imperial College London who is a co-author of the study, which was published Wednesday in Science Advances. © 2019 The New York Times Company

Keyword: Sleep; Evolution
Link ID: 25978 - Posted: 02.21.2019

Nicola Davis The mystery of how the zebra got its stripes might have been solved: researchers say the pattern appears to confuse flies, discouraging them from touching down for a quick bite. The study, published in the journal Plos One, involved horses, zebras, and horses dressed as zebras. The team said the research not only supported previous work suggesting stripes might act as an insect deterrent, but helped unpick why, revealing the patterns only produced an effect when the flies got close. Dr Martin How, co-author of the research from the University of Bristol, said: “The flies seemed to be behaving relatively naturally around both [zebras and horses], until it comes to landing. “We saw that these horseflies were coming in quite fast and almost turning away or sometimes even colliding with the zebra, rather than doing a nice, controlled flight.” Researchers made their discovery by spending more than 16 hours standing in fields and noting how horseflies interacted with nine horses and three zebras – including one somewhat bemusingly called Spot. While horseflies circled or touched the animals at similar rates, landing was a different matter, with a lower rate seen for zebras than horses. To check the effect was not caused by a different smell of zebras and horses, for example, the researchers put black, white and zebra-striped coats on seven horses in turn. While there was no difference in the rate at which the flies landed on the horses’ exposed heads, they touched and landed on the zebra coat far less often than either the black or white garment. © 2019 Guardian News & Media Limited

Keyword: Vision; Evolution
Link ID: 25977 - Posted: 02.21.2019

Catherine Offord The Japanese government’s health ministry has given the go-ahead for a trial of human induced pluripotent stem cells to treat spinal cord injury, Reuters reports today (February 18). Researchers at Keio University plan to recruit four adults who have sustained recent nerve damage in sports or traffic accidents. “It’s been 20 years since I started researching cell treatment. Finally we can start a clinical trial,” Hideyuki Okano of Keio University School of Medicine told a press conference earlier today, The Japan Times reports. “We want to do our best to establish safety and provide the treatment to patients.” The team’s intervention involves removing differentiated cells from patients and reprogramming them via human induced pluripotent stem cells (iPSCs) into neural cells. Clinicians will then inject about 2 million of these cells into each patient’s site of injury. The approach has been successfully tested in a monkey, which recovered the ability to walk after paralysis, according to the Times. It’s not the first time Japan has approved the use of iPSCs in clinical trials. Last year, researchers at Kyoto University launched a trial using the cells to treat Parkinson’s disease. And in 2014, a team at the RIKEN Center for Developmental Biology led the first transplant of retina cells grown from iPSCs to treat a patient’s eye disease. © 1986 - 2019 The Scientist

Keyword: Regeneration; Stem Cells
Link ID: 25976 - Posted: 02.21.2019

Ian Sample Science editor Scientists are developing a radical form of gene therapy that could cure a devastating medical disorder by mending mutations in the brains of foetuses in the womb. The treatment, which has never been attempted before, would involve doctors injecting the feotus’s brain with a harmless virus that infects the neurons and delivers a suite of molecules that correct the genetic faults. Tests suggest that the therapy will be most effective around the second trimester, when their brains are in the early stages of development. “We believe that this could provide a treatment, if not a cure, depending on when it’s injected,” said Mark Zylka, a a neurobiologist at the University of North Carolina. The therapy is aimed at a rare brain disorder known as Angelman syndrome, which affects one in 15,000 births. Children with the condition have small brains and often experience seizures and problems with walking and sleeping. They can live their whole lives without speaking a word. Zylka said children with Angelman syndrome can have such severe sleeping difficulties that parents can feel they must lock them in their rooms at night to prevent them from getting up and having accidents around the house. Healthy people tend to have two copies of every gene in the genetic code, one inherited from their mother and the other from their father. But both copies are not always switched on. For normal brain development, the mother’s copy of a gene called UBE3A is switched on, while the father’s copy is silenced. © 2019 Guardian News & Media Limited

Keyword: Development of the Brain
Link ID: 25975 - Posted: 02.19.2019

Fergus Walsh Medical correspondent A woman from Oxford has become the first person in the world to have gene therapy to try to halt the most common form of blindness in the Western world. Surgeons injected a synthetic gene into the back of Janet Osborne's eye in a bid to prevent more cells from dying. It is the first treatment to target the underlying genetic cause of age-related macular degeneration (AMD). About 600,000 people in the UK are affected by AMD, most of whom are severely sight impaired. Janet Osborne told BBC News: "I find it difficult to recognise faces with my left eye because my central vision is blurred - and if this treatment could stop that getting worse, it would be amazing." The treatment was carried out under local anaesthetic last month at Oxford Eye Hospital by Robert MacLaren, professor of ophthalmology at the University of Oxford. He told BBC News: "A genetic treatment administered early on to preserve vision in patients who would otherwise lose their sight would be a tremendous breakthrough in ophthalmology and certainly something I hope to see in the near future." Mrs Osborne, 80, is the first of 10 patients with AMD taking part in a trial of the gene therapy treatment, manufactured by Gyroscope Therapeutics, funded by Syncona, the Wellcome Trust founded investment firm. The macula is part of the retina and responsible for central vision and fine detail. In age-related macular degeneration, the retinal cells die and are not renewed. The risk of getting AMD increases with age. © 2019 BBC.

Keyword: Vision
Link ID: 25974 - Posted: 02.19.2019

Laura Sanders Sometimes a really good meal can make an evening unforgettable. A new study of rats, published online February 18 in the Journal of Neuroscience, may help explain why. A select group of nerve cells in rats’ brains holds information about both flavors and places, becoming active when the right taste hits the tongue when the rat is in a certain location. These double-duty cells could help animals overlay food locations onto their mental maps. Researchers implanted electrodes into the hippocampus, an area of the brain that is heavily involved in both memory formation and mapping. The rats then wandered around an enclosure, allowing researchers to identify “place cells” that become active only when the rat wandered into a certain spot. At the same time, researchers occasionally delivered one of four flavors (sweet, salty, bitter and plain water) via an implanted tube directly onto the wandering rats’ tongues. Some of the active place cells also responded to one or more flavors, but only when the rat was in the right spot within its enclosure. When the rat moved away from a place cell’s preferred spot, that cell no longer responded to the flavor, the researchers found. A mental map of the best spots for tasting something good would come in handy for an animal that needs to find its next meal. Citations L.E. Herzog et al. Interaction of taste and place coding in the hippocampus. Journal of Neuroscience. Published online February 18, 2019. doi: 10.1523/JNEUROSCI.2478-18.2019. |© Society for Science & the Public 2000 - 2019

Keyword: Chemical Senses (Smell & Taste)
Link ID: 25973 - Posted: 02.19.2019

By Perri Klass, M.D. A major international study provides new reassurance around the question of whether young children who have anesthesia are more likely to develop learning disabilities The issue has troubled pediatric anesthesiologists and parents for well over a decade, after research on animals suggested that there was a connection. Do the drugs that make it possible to perform vital surgical procedures without pain cause lasting damage to the developing human brain? Several large studies have found ways to tease out the effects of actual surgeries and anesthetic exposures on children. The new study, in the British journal The Lancet, is a randomized controlled trial involving more than 700 infants who needed hernia repairs. The babies, at 28 hospitals in seven countries, were randomly assigned to receive either general anesthesia or regional (spinal) anesthesia for these short operations — the mean duration of general anesthesia was 54 minutes. The study, called the GAS study — for general anesthesia compared to spinal — compared neurodevelopmental outcomes at 5 years of age, and found no significant difference in the children’s performance in the two groups. Dr. Andrew Davidson, a professor in the department of anesthesia at the Royal Children’s Hospital of Melbourne and one of the two lead investigators on the trial, said that this prospective, randomized design allows researchers to avoid many confounding factors that have complicated previous studies, and answer a very specific question. Preliminary data from testing the children at age 2 had shown no significant differences between the groups, and the children were then evaluated at the age of school entry. “If you have an hour of anesthesia as a child, then you are at no greater risk of deficits of cognition at the age of 5,” Dr. Davidson said. “It doesn’t increase the risk of poor neurodevelopmental outcome.” © 2019 The New York Times Company

Keyword: Development of the Brain; Learning & Memory
Link ID: 25972 - Posted: 02.18.2019