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

Jules Howard It’s a bit garbled but you can definitely hear it in the mobile phone footage. As the chimpanzees arrange their branches into a makeshift ladder and one of them makes its daring escape from its Belfast zoo enclosure, some words ring out loud and clear: “Don’t escape, you bad little gorilla!” a child onlooker shouts from the crowd. And … POP … with that a tiny explosion goes off inside my head. Something knocks me back about this sentence. It’s a “kids-say-the-funniest things” kind of sentence, and in any other situation I’d offer a warm smile and a chuckle of approval. But not this time. This statement has brought out the pedant in me. At this point, you may wonder if I’m capable of fleshing out a 700-word article chastising a toddler for mistakenly referring to a chimpanzee as a gorilla. The good news is that, though I am more than capable of such a callous feat, I don’t intend to write about this child’s naive zoological error. In fact, this piece isn’t really about the (gorgeous, I’m sure) child. It’s about us. You and me, and the words we use. So let’s repeat it. That sentence, I mean. “Don’t escape, you bad little gorilla!” the child shouted. The words I’d like to focus on in this sentence are the words “you” and “bad”. The words “you” and “bad” are nice examples of a simple law of nearly all human languages. They are examples of Zipf’s law of abbreviation, where more commonly used words in a language tend to be shorter. It’s thought that this form of information-shortening allows the transmission of more complex information in a shorter amount of time, and it’s why one in four words you and I write or say is likely to be something of the “you, me, us, the, to” variety. © 2019 Guardian News & Media Limited

Keyword: Language; Evolution
Link ID: 25971 - Posted: 02.18.2019

Bruce Bower WASHINGTON — Beliefs among some university professors that intelligence is fixed, rather than capable of growth, contribute to a racial achievement gap in STEM courses, a new study suggests. Those professors may subtly communicate stereotypes about blacks, Hispanics and Native Americans allegedly being less intelligent than Asians and whites, say psychologist Elizabeth Canning of Indiana University in Bloomington and her colleagues. In turn, black, Hispanic and Native American undergraduates may respond by becoming less academically motivated and more anxious about their studies, leading to lower grades. Even small dips in STEM grades — especially for students near pass/fail cutoffs — can accumulate across the 15 or more science, technology, engineering and math classes needed to become a physician or an engineer, Canning says. That could jeopardize access to financial aid and acceptance to graduate programs. “Our work suggests that academic benefits could accrue over time if all students, and particularly underrepresented minority students, took STEM classes with faculty who endorse a growth mind-set,” Canning says. Underrepresented minority students’ reactions to professors with fixed or flexible beliefs about intelligence have yet to be studied. But over a two-year period, the disparity in grade point averages separating Asian and white STEM students from black, Hispanic and Native American peers was nearly twice as large in courses taught by professors who regarded intelligence as set in stone, versus malleable, Canning’s team reports online February 15 in Science Advances. |© Society for Science & the Public 2000 - 2019.

Keyword: Attention; Learning & Memory
Link ID: 25970 - Posted: 02.18.2019

A genetic variant found only in people of African descent significantly increases a smoker’s preference for cigarettes containing menthol, a flavor additive. The variant of the MRGPRX4 gene is five to eight times more frequent among smokers who use menthol cigarettes than other smokers, according to an international group of researchers supported by the U.S. Food and Drug Administration and the National Institutes of Health. The multiethnic study is the first to look across all genes to identify genetic vulnerability to menthol cigarettes. The paper was published online in the journal PLOS Genetics (link is external) on Feb. 15. Menthol provides a minty taste and a cooling or soothing sensation, and plays a particularly troubling role in U.S. cigarette smoking patterns. According to the FDA, nearly 20 million people in the United States smoke menthol cigarettes, which are particularly popular among African-American smokers and teen smokers. In the U.S., 86 percent of African-American smokers use menthol cigarettes, compared to less than 30 percent of smokers of European descent. In addition, menthol cigarettes may be harder to quit than other cigarettes. Although not originally the focus of the study, researchers also uncovered clues as to how menthol may reduce the irritation and harshness of smoking cigarettes. “This study sheds light on the molecular mechanisms of how menthol interacts with the body,” said Andrew Griffith, M.D., Ph.D., scientific director and acting deputy director of NIH’s National Institute on Deafness and Other Communications Disorders (NIDCD). “These results can help inform public health strategies to lower the rates of harmful cigarette smoking among groups particularly vulnerable to using menthol cigarettes.”

Keyword: Drug Abuse; Genes & Behavior
Link ID: 25969 - Posted: 02.18.2019

By Emily Underwood Alert! “Cats Can Literally Make You Crazy.” Wait! “Cats Don't Cause Mental Illness.” The news headlines are as alarming as they are contradictory. All refer to Toxoplasma gondii, a brain parasite carried by our feline companions that infects roughly one in three people. Scientists have long hypothesized that T. gondii plays a role in mental illness, including schizophrenia. But though more than 100 studies have found a correlation, none has shown that the parasite actually causes mental illness. So what’s really going on? Here’s what you need to know: T. gondii is not a bacterium or a virus, but a single-celled microscopic organism distantly related to the parasite that causes malaria. Cats get T. gondii and the disease it causes, toxoplasmosis, by eating infected rodents, birds, and other animals. Estimates suggest about 40% of cats in the United States are infected; most don’t show any symptoms, but they can develop jaundice or blindness and experience personality changes if the parasite spreads to the liver or nervous system. In the first few weeks after infection, a cat can shed millions of hardy egg pods called oocysts into its litterbox each day. Although some people get toxoplasmosis from direct contact with domestic cats and cat feces, many more are infected when oocysts shed by cats make it into the soil and water, where they can survive for a year or longer. © 2019 American Association for the Advancement of Science.

Keyword: Schizophrenia; Neuroimmunology
Link ID: 25968 - Posted: 02.15.2019

The brain function of very late risers and "morning larks" during the hours of the working day is different, according to a study. Researchers scanned the brains of night owls with a bedtime of 02:30 and a wake time of 10:15, along with early risers. The tests - performed between 08:00 and 20:00 - found night owls had less connectivity in brain regions linked to maintaining consciousness. They also had poorer attention, slower reactions and increased sleepiness. Researchers said it suggested that night owls were disadvantaged by the "constraints" of the typical working day. They called for more research to understand the health implications of night owls performing on a work or school schedule to which they are not naturally suited. Scientists took 38 people who were either night owls or morning larks (people who went to bed just before 23:00 and woke at 06:30) and investigated their brain function at rest using magnetic resonance imaging (MRI) scans. The volunteers then carried out a series of tasks at various times, from 08:00 to 20:00, and were asked to report on their levels of sleepiness. Morning larks were least sleepy and had their fastest reaction time in the early morning tests. They were also found to perform significantly better at this time than night owls. In contrast, night owls were least sleepy and had their fastest reaction time at 20:00, although they did not do significantly better than the larks at this time. The brain connectivity in the regions that predicted better performance and lower sleepiness was significantly higher in larks at all time points, suggesting connectivity in late risers is impaired throughout the whole working day, researchers said. © 2019 BBC

Keyword: Biological Rhythms
Link ID: 25967 - Posted: 02.15.2019

By Pallab Ghosh Science correspondent, BBC News, Washington DC New results suggest ageing brains can potentially be rejuvenated, at least in mice, according to researchers. Very early-stage experiments indicate that drugs can be developed to stop or even reverse mental decline. The results were presented at the 2019 meeting of the American Association for the Advancement of Science. The US and Canadian researchers took two new approaches to trying to prevent the loss of memory and cognitive decline that can come with old age. One team, from the University of California, Berkeley, showed MRI scans which indicated that mental decline may be caused by molecules leaking into the brain. Blood vessels in the brain are different from those in other parts of the body. They protect the organ by allowing only nutrients, oxygen and some drugs to flow through into the brain, but block larger, potentially damaging molecules. This is known as the blood-brain barrier. The scans revealed that this barrier becomes increasingly leaky as we get older. For example, 30-40% of people in their 40s have some disruption to their blood-brain barrier, compared with 60% of 60-year-olds. The scans also showed that the brain was inflamed in the leaky areas. Prof Daniela Kaufer, who leads the Berkeley group, said that young mice altered to have leaky blood-brain barriers showed many signs of aging. She discovered a chemical that stops the damage to the barrier from causing inflammation to the brain. Prof Kaufer told BBC News that not only did the chemical stop the genetically altered young mice from showing signs of aging, it reversed the signs of aging in older mice. © 2019 BBC

Keyword: Alzheimers; Learning & Memory
Link ID: 25966 - Posted: 02.15.2019

By Kelly Servick Rough sleep is bad for your mind—and your heart. It can increase the risk of clogged arteries, which can lead to stroke or heart attacks. But how these two things are connected has been a mystery. Now, a study in mice reveals a link, based on signals the brain sends to bone marrow. If the story holds true in humans, the mechanism could help explain the connection between sleep and other conditions, from obesity to cancer. “Not everyone who is sleep-deprived develops cardiovascular disease,” says Namni Goel, a behavioral neuroscientist at the University of Pennsylvania Perelman School of Medicine in Philadelphia who was not involved in the work. The new mouse work “opens the door for human studies” that could sort out who is most at risk. In many forms of cardiovascular disease, fatty deposits build up on artery walls (a condition called atherosclerosis) and can rupture to cause a stroke or heart attack. Immune cells—in particular, white blood cells called monocytes—also play a key role. They flock to sites where these deposits have damaged blood vessels and they spawn cells that can contribute to the growing plaque. To follow up on the known connection between sleep and heart disease, immunologist Filip Swirski of Harvard Medical School and Massachusetts General Hospital in Boston wanted to explore whether sleep somehow triggered an immune process that spurs this dangerous buildup. © 2019 American Association for the Advancement of Science

Keyword: Sleep; Learning & Memory
Link ID: 25965 - Posted: 02.14.2019

Ian Sample Science editor An experimental drug that bolsters ailing brain cells has raised hopes of a treatment for memory loss, poor decision making and other mental impairments that often strike in old age. The drug could be taken as a daily pill by over-55s if clinical trials, which are expected to start within two years, show that the medicine is safe and effective at preventing memory lapses. Tests in the lab showed that old animals had far better memory skills half an hour after receiving the drug. After two months on the treatment, brain cells which had shrunk in the animals had grown back, scientists found. Etienne Sibille, at the Centre for Addiction and Mental Health in Toronto, said the treatment was aimed not only at the “normal” cognitive decline that leads to senior moments, but at memory loss and mental impairments that commonly afflict people with depression, schizophrenia and Alzheimer’s disease. If the drug did well in human trials, Sibille said it was possible that “anybody over the age of 55-60 who may be at risk of cognitive problems later on could benefit from this treatment”. “Our findings have direct implications for poor cognition in normal ageing,” he said, with the drug potentially improving learning, memory, decision making and essential life planning. “But we see this deficiency across disorders from depression to schizophrenia and Alzheimer’s.” © 2019 Guardian News & Media Limited

Keyword: Alzheimers; Learning & Memory
Link ID: 25964 - Posted: 02.14.2019

Shawna Williams Watch a bacterium chase down the source of an enticing molecular trail using chemo-taxis, and it’s clear that its sensory and navigation abilities are tightly linked. But could the same be true for humans? In 2014, Louisa Dahmani, then a graduate student at McGill University in Montreal, set out to answer that question. After having reviewed the literature on studies of spatial memory and olfaction in people, “I realized that the two functions seemed to rely on similar brain regions,” she explains. “But no one had actually looked at it directly and tested the same sample of participants on an olfaction and on a spatial memory task.” Dahmani, her advisor Véronique Bohbot, and their colleagues set out to rectify that. The group recruited 60 volunteers and tested their ability to identify 40 odors, from menthol to cucumber to lavender. The researchers also had the subjects do a computer-based task in which they moved through a virtual town. After their exploration, the subjects navigated through the virtual town from one of its eight landmarks to a different destination via the shortest route possible. “People who are better at finding their way are also better at identifying smells,” Dahmani says, summing up the study’s biggest takeaway. The scientists also imaged participants’ brains using MRI and found that a larger medial orbitofrontal cortex—a brain region known to be associated, along with the hippocampus, with spatial navigation—correlated with both better smell identification and fewer errors on the navigation task (Nat Comm, 9:4162, 2018). © 1986 - 2019 The Scientist.

Keyword: Chemical Senses (Smell & Taste); Learning & Memory
Link ID: 25963 - Posted: 02.14.2019

By Nicholas Bakalar Chronic inflammation in middle age may lead to memory and thinking problems later in life. Unlike acute inflammation, which arises in response to injury, chronic inflammation persists over months or years. Autoimmune disease, lingering infection, exposure to polluted air, psychological stress and other conditions can all promote chronic inflammation. Researchers did blood tests on 12,336 men and women, average age 57, assigning them an “inflammation composite score” based on white blood cell count, clotting factors and other tests. They also assessed their cognition with standardized tests of memory, processing speed and verbal fluency. The study is in Neurology. After controlling for age, education, blood pressure, cholesterol, heart disease and many other factors, they found that the greater the number of inflammatory factors, the steeper the cognitive decline over 20 years of follow-up. Inflammation was most strongly associated with declines in memory. “We know that dementia starts earlier than the appearance of symptoms,” said the lead author, Keenan A. Walker, a postdoctoral researcher at Johns Hopkins, “and we’ve shown that levels of inflammation matter for dementia risk. Reducing chronic inflammation involves the same health behaviors that we already know are important for other reasons — regular exercise, healthy diet, avoiding excessive weight gain and so on.” © 2019 The New York Times Company

Keyword: Alzheimers; Neuroimmunology
Link ID: 25962 - Posted: 02.14.2019