By Elizabeth Preston A clown fish uses his fins to fan water across a glistening mass of eggs, keeping them aerated. A silver arowana scoops up his fertilized eggs with his mouth and holds them gently for two months, until a host of miniature adults swims free from his jaws. A seahorse drifts through coral, his belly pouch swollen with unborn young. Most fish are uninvolved parents. They dump their eggs and sperm, then swim off and let nature take its course. But some species of fish take their parental duties more seriously — and among them, the majority of caring parents are dads. Care from mothers, or from both parents at once, is much less common. In a study published last fall in Evolution, researchers found evidence that paternal care, the system in which dads are the sole caretakers, has evolved dozens of times in fish. These fish aren’t exactly helicopter dads. Their most common parenting style is simply guarding eggs after they’re fertilized. “Some people are surprised this is considered care,” said Frieda Benun Sutton, an evolutionary biologist at the City University of New York. But it does count. To learn more about why this type of care in fish usually comes from dads, Dr. Benun Sutton and her co-author, Anthony Wilson, of Brooklyn College, took a deep dive into the family history of fish parents. They started with an evolutionary tree, built by other researchers in 2017 using genetic data, that shows how almost 2,000 fish species are related. Then they mapped onto the tree all the information they could find about parental care in those species: Were young cared for by fathers, mothers, both or nobody? They also added other factors including the size and number of each fish’s eggs and how they’re fertilized. The completed tree showed that care by fathers is no evolutionary accident: It has arisen at least 30 separate times. Hundreds of the species in this sample have absent mothers and caring fathers. But why? © 2020 The New York Times Company

Keyword: Sexual Behavior; Evolution
Link ID: 27316 - Posted: 06.22.2020

By Bret Stetka How do humans and other animals distinguish between the smell of rotting seafood or the enticing allure of a ripe banana? New research at New York University Langone Health and their colleagues uses artificially created odors to help reveal the intricate chain of events that allow one odor to be distinguished from another. The results were published today in Science. In the deep recesses of the nose are millions of sensory neurons that, along with our eyes and ears, help conjure the world around us. When stimulated by a chemical with a smell, or an odorant, they send nerve impulses to thousands of clusters of neurons in the glomeruli, which make up the olfactory bulb, the brain’s smell center. Different patterns of glomerular activation are known to generate the sensation of specific odors. Firing one set of glomeruli elicits the perception of pineapples; firing another evokes pickles. Unlike other sensations, such as sight and hearing, scientists do not know which qualities of a particular smell are used by the brain to perceive it. When you see a person’s face, you may remember the eyes, which helps you recognize that individual in the future. But the ears and nose might be less important in how the brain represents that person. The authors of the new study sought to identify distinguishing features involved in forming the representation of odors in the brain. To do so, they used a technique called optogenetics to activate glomeruli in mice. Optogenetics uses light to stimulate specific neurons in the brain. And it can help determine the function of particular brain regions. © 2020 Scientific American

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27315 - Posted: 06.22.2020

by Laura Dattaro Children with autism are more likely than typical children to have had problems falling asleep as infants, according to a new study1. These infants also have more growth in the hippocampus, the brain’s memory hub, from age 6 to 24 months. The study is the first to link sleep problems to altered brain development in infants later diagnosed with autism. Sleep difficulties are common in autistic children: Nearly 80 percent of autistic preschoolers have trouble sleeping2. But little is known about the interplay between sleep and brain development in early life, says lead investigator Annette Estes, director of the UW Autism Center at the University of Washington in Seattle. The researchers examined the sleep patterns and brain scans of infants who have autistic older siblings, a group known as ‘baby sibs.’ Baby sibs are 20 times as likely to be diagnosed with autism as are children in the general population, and they often show signs of autism early in life. The study shows an association between sleep problems and brain structure in babies who have autism. But it is too early to say whether sleep troubles contribute to brain changes and autism traits or vice versa, or whether some common factor underlies all three, Estes says. It is also not clear what, if any, connection exists between these findings and the well-documented sleep problems in older autistic children. © 2020 Simons Foundation

Keyword: Autism; Sleep
Link ID: 27314 - Posted: 06.22.2020

By Veronique Greenwood Hummingbirds were already impressive. They move like hurried insects, turn on aerial dimes and extract nectar from flowers with almost surgical precision. But they conceal another talent, too: seeing colors that human eyes can’t perceive. Ultraviolet light from the sun creates colors throughout the natural world that are never seen by people. But researchers working out of the Rocky Mountain Biological Laboratory reported on Monday in Proceedings of the National Academy of Sciences that untrained broad-tailed hummingbirds can use these colors to help them identify sources of food. Testing 19 pairings of colors, the team found that hummingbirds are picking up on multiple colors beyond those we can see. From the bird’s-eye view, numerous plants and feathers have these as well, suggesting that they live in a richer-hued world than we do, full of signs and messages that we never notice. Compared with the color vision of many other animals, that of humans leaves something to be desired. The perception of color relies on cone cells in the retina, each of which responds to different wavelengths of light. Humans have three kinds of cone cells, which, when light reflects off an apple, a leaf or a field of daffodils, send signals that are combined in the brain to generate the perception of red, green or yellow. Birds, however, have four types of cones, including one that is sensitive to ultraviolet light. (And they are far from the most generously endowed — mantis shrimp, for instance, have 16.) In lab experiments, birds readily pick up on UV light and UV yellow, a mixture of UV light and visible yellow wavelengths, says Mary Caswell Stoddard, a professor of evolutionary biology at Princeton University and an author of the new study. Likewise, researchers have long known that UV colors are widespread in the natural world, though we can’t see them. However, experiments to see whether wild birds would use UV colors in their daily lives had not yet been performed. © 2020 The New York Times Company

Keyword: Vision; Evolution
Link ID: 27313 - Posted: 06.22.2020

By Laura Sanders Scientists have implanted an artificial odor directly in the brains of mice. It doesn’t mean that mental Smell-O-Vision technology is coming soon. But the results, published June 18 in Science, deliver clues to how the brain processes information. Details about the synthetic smell may help answer “fundamental questions in olfaction,” says computational biologist Saket Navlakha of Cold Spring Harbor Laboratory in New York, who wasn’t involved in the study. Studies on the senses offer a window into how brains shape signals from the outside world into perceptions, and how those perceptions can guide behavior (SN: 7/18/19). To build artificial smells in mice’s brains, researchers used optogenetics, a technique in which light prods genetically engineered nerve cells to fire signals (SN: 1/15/10). Neuroscientist Dima Rinberg of New York University’s Grossman School of Medicine and colleagues targeted nerve cells in mice’s olfactory bulbs. There, clusters of nerve endings called glomeruli organize the smell signals picked up in the nose. Like playing a short ditty on a piano, Rinberg and colleagues activated nerve cells in six spots (each of which might include between one and three glomeruli) in a certain order. This neural melody was designed to be a simplified version of how a real odor might play those nerve cells. (It’s not known what the artificial odor actually smells like to a mouse.) © Society for Science & the Public 2000–2020.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27312 - Posted: 06.19.2020

Jon Hamilton A neurologist who encased his healthy right arm in a pink fiberglass cast for two weeks has shown how quickly the brain can change after an injury or illness. Daily scans of Dr. Nico Dosenbach's brain showed that circuits controlling his immobilized arm disconnected from the body's motor system within 48 hours. But during the same period, his brain began to produce new signals seemingly meant to keep those circuits intact and ready to reconnect quickly with the unused limb. Dosenbach, an assistant professor at Washington University School of Medicine in St. Louis, repeated the experiment on two colleagues (their casts were purple and blue) and got the same result. In all three people, the disconnected brain circuits quickly reconnected after the cast was removed. The study, published online in the journal Neuron, shows that "within a few days, we can rearrange some of the most fundamental, most basic functional relationships of the brain," Dosenbach says. It suggests it is possible to reverse brain changes caused by disuse of a limb after a stroke or brain injury. The results of the study appear to support the use of something called constraint-induced movement therapy, or CIMT, which helps people – usually children — regain the use of a disabled arm or hand by constraining the other, healthy limb with a sling, splint or cast. Previous studies of CIMT have produced mixed results, in part because they focused on brain changes associated with increased use of a disabled arm, Dosenbach says. "We looked at the effect of actually not using an arm because we thought that was a much more powerful intervention," he says. © 2020 npr

Keyword: Stroke
Link ID: 27311 - Posted: 06.19.2020

By Elizabeth Pennisi When Muhammad Ali duked it out with Joe Frazier in the boxing ring, it’s unlikely anyone thought about what was happening to the genes inside their heads. But a new study in fighting fish has demonstrated that as the fish spar, genes in their brains begin to turn on and off in a coordinated way. It’s still unclear what those genes are doing or how they influence the skirmish, but similar changes may be happening in humans. The work is “a really cool example of the way that social interactions can get under the skin,” says Alison Bell, a behavioral ecologist at the University of Illinois, Urbana-Champaign, who was not involved with the study. The molecular basis of how animals, humans included, coordinate behaviors is a mystery. Whether it be mating or fighting, “animals need to be really good at this, but we don’t particularly know how they do it,” says Hans Hofmann, an evolutionary social neuroscientist at the University of Texas, Austin. When molecular biologist Norihiro Okada at Kitasato University in Japan first saw Siamese fighting fish (Betta splendens) on TV, he realized the animals could help solve this mystery. Native to Thailand, these goldfish-size swimmers have been bred to have very large, vibrantly colored fins and tails. Aquarium owners tend to keep their pets, or “bettas” as they are often called, separate. The fish are territorial and can get into fights that last more than 1 hour, with strikes, bites, and chases (as seen in the video below). They will even lock jaws in a fish version of an arm wrestle. Okada and colleagues videotaped more than a dozen hours of fights between 17 pairs of fish and then analyzed what happened—and when—in each fight. The longer the fight, the more the fish synchronize their behavior, timing their circling, striking, and biting more than anyone had ever realized, the researchers report today in PLOS Genetics. © 2020 American Association for the Advancement of Science.

Keyword: Aggression; Epigenetics
Link ID: 27310 - Posted: 06.19.2020

Combining more healthy lifestyle behaviors was associated with substantially lower risk for Alzheimer’s disease in a study that included data from nearly 3,000 research participants. Those who adhered to four or all of the five specified healthy behaviors were found to have a 60% lower risk of Alzheimer’s. The behaviors were physical activity, not smoking, light-to-moderate alcohol consumption, a high-quality diet, and cognitive activities. Funded by the National Institute on Aging (NIA), part of the National Institutes of Health, this research was published in the June 17, 2020, online issue of Neurology, the medical journal of the American Academy of Neurology. The research team reviewed data from two NIA-funded longitudinal study populations: The Chicago Health and Aging Project (CHAP)(link is external) and the Memory and Aging Project (MAP)(link is external). They selected participants from those studies who had data available on their diet, lifestyle factors, genetics, and clinical assessments for Alzheimer’s disease. The resulting data pool included 1,845 participants from CHAP and 920 from MAP. The researchers scored each participant based on five healthy lifestyle factors, all of which have important health benefits: At least 150 minutes per week of moderate- to vigorous-intensity physical activity – Physical activity is an important part of healthy aging. Not smoking – Established research has confirmed that even in people 60 or older who have been smoking for decades, quitting will improve health. Light-to-moderate alcohol consumption – Limiting use of alcohol may help cognitive health. A high-quality, Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, which combines the Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) diet – The MIND diet focuses on plant-based foods linked to dementia prevention. Engagement in late-life cognitive activities – Being intellectually engaged by keeping the mind active may benefit the brain.

Keyword: Alzheimers
Link ID: 27309 - Posted: 06.19.2020

By Lisa Friedman and Coral Davenport WASHINGTON — The Trump administration on Thursday finalized a decision not to impose any limits on perchlorate, a toxic chemical compound found in rocket fuel that contaminates water and has been linked to fetal and infant brain damage. The move by the Environmental Protection Agency was widely expected, after The New York Times reported last month that Andrew Wheeler, the E.P.A. administrator, had decided to effectively defy a court order that required the agency to establish a safe drinking-water standard for the chemical by the end of June. In addition to not regulating, the E.P.A. overturned the underlying scientific finding that declared perchlorate a serious health risk for five million to 16 million people in the United States. The E.P.A. said California and Massachusetts and other states had already taken regulatory steps to reduce the contamination. “Today’s decision is built on science and local success stories and fulfills President Trump’s promise to pare back burdensome ‘one-size-fits-all’ overregulation for the American people,” Mr. Wheeler said in a statement. “State and local water systems are effectively and efficiently managing levels of perchlorate. Our state partners deserve credit for their leadership on protecting public health in their communities, not unnecessary federal intervention.” Environmentalists said both moves showed a disregard for science, the law and public health, and they criticized the agency for claiming credit for state regulations done in the face of federal inaction. “Today’s decision is illegal, unscientific and unconscionable,” said Erik D. Olson, the senior strategic director for health at the Natural Resources Defense Council, an advocacy group. “The Environmental Protection Agency is threatening the health of pregnant moms and young children with toxic chemicals in their drinking water at levels that literally can cause loss of I.Q. points. Is this what the Environmental Protection Agency has come to?” © 2020 The New York Times Company

Keyword: Neurotoxins; Development of the Brain
Link ID: 27308 - Posted: 06.19.2020

By Simon Makin on June 15, 2020 A well-worn science-fiction trope imagines space travelers going into suspended animation as they head into deep space. Closer to reality are actual efforts to slow biological processes to a fraction of their normal rate by replacing blood with ice-cold saline to prevent cell death in severe trauma. But saline transfusions or other exotic measures are not ideal for ratcheting down a body’s metabolism because they risk damaging tissue. Coaxing an animal into low-power mode on its own is a better solution. For some animals, natural states of lowered body temperature are commonplace. Hibernation is the obvious example. When bears, bats or other animals hibernate, they experience multiple bouts of a low-metabolism state called torpor for days at a time, punctuated by occasional periods of higher arousal. Mice enter a state known as daily torpor, lasting only hours, to conserve energy when food is scarce. The mechanisms that control torpor and other hypothermic states—in which body temperatures drop below 37 degrees Celsius—are largely unknown. Two independent studies published in Nature on Thursday identify neurons that induce such states in mice when they are stimulated. The work paves the way toward understanding how these conditions are initiated and controlled. It could also ultimately help find methods for inducing hypothermic states in humans that will prove useful in medical settings. And more speculatively, such methods might one day approximate the musings about suspended animation that turn up in the movies. One of the two studies was conducted by neuroscientist Takeshi Sakurai of the University of Tsukuba in Japan and his colleagues. It began with a paradoxical finding about a peptide called QRFP. The team showed that injecting it into animals actually increased their activity. But when the researchers switched on neurons that were making the peptide in mice, they got a surprise. “The mice stayed still and were very cold: the opposite to what they expected,” says Genshiro Sunagawa, of the RIKEN Center for Biosystems Dynamics Research in Japan, who co-led the study. The animals’ metabolic rate (measured by oxygen consumption), body temperature, heart rate and respiration all dropped. © 2020 Scientific American,

Keyword: Sleep
Link ID: 27307 - Posted: 06.17.2020

By Susan Burton “Diet” is a strange word, used to describe both a deviation from the norm and the norm itself: the foods that make up a day, a week, a lifetime. From the beginning, my diet was a big part of my story, even the one that others told about me. “All babies like rice cereal,” my mother will say. “But you didn’t.” In the high chair, I would tighten my lips and turn away. When I was two, at the first preschool parent-teacher conference, they told my mother, “Susan never eats snack.” Recalling encounters with foods I disliked as a small child raises an old alarm in me. A sip of a soda at the zoo one afternoon, the prickling shock of the bubbles. It would be more than a decade before I would try something fizzy again. Melba toast at a white-tablecloth restaurant in Chicago. The next day, I vomited. The bright yellow worm of mustard on a hot dog at a public beach. The jagged chopped nuts on a hot-fudge sundae, even though I’d asked for it plain. In any choice related to food, I always preferred plain. I went through primary school never eating a salad or a single bite of fruit. The term “picky eater” didn’t apply to me. Picky eaters had to be reminded to pay attention to their plates. But I never forgot about food, in the way you never forget about anything you fear. I was scared of feeling sick. I was scared of not liking tastes. I was scared of something getting in me that I could never get out. I was scared of something happening to my body that would make me not me. In many ways, my adolescence was stereotypical. I was an awkward middle-schooler who transformed herself with the help of Seventeen magazine. I stood in bleachers at Friday-night football games. I read Sylvia Plath and wrote furiously in my journal. I learned to smoke cigarettes on a weekday afternoon in a wood-panelled car. I signed the notes I passed in class “Love, Susan.” I tried to be the perfect teen-age girl. But I was also a troubled one, and the dark part of my adolescence became its heart. © 2020 Condé Nast.

Keyword: Anorexia & Bulimia
Link ID: 27306 - Posted: 06.17.2020

Tracking the brain’s reaction to virtual-reality-simulated threats such as falling rocks and an under-researched fear reduction strategy may provide better ways of treating anxiety disorders and preventing relapses. Hippocrates described them as ‘masses of terrors,’ while French physicians in the 18th century labelled them as ‘vapours’ and ‘melancholia.’ Nowadays we know that panic attacks, a common symptom of anxiety, can be linked to intense phobias or even a general anxiety disorder with no specific source. ‘But if you’re not sure what a panic attack is, it’s very frightening,’ said Dr Iris Lange, a psychologist based at KU Leuven, in Belgium. ‘You probably think you will get a heart attack. We see a lot of people having to go to the medical emergency services.’ According to an EU and OECD report from 2018, anxiety disorders are the most common mental disorder across European Union countries and affect an estimated 25 million people. Decades of research have shown how anxiety amplifies sensitivity to threats. People with high anxiety will perceive even non-harmful things, such as insects, as potential threats. However, researchers have until recently used mice and rat experiments to understand the neuroscientific concepts of how anxiety patients behave when defending themselves from such perceived threats. ‘We are translating concepts that are probably not translatable (to humans), or we're just translating very core concepts,’ said Professor Dominik R Bach, a neuroscientist at University College London, in the UK.

Keyword: Stress; Learning & Memory
Link ID: 27305 - Posted: 06.17.2020

by Tessa van Leeuwen, Rob van Lier Have you ever considered what your favorite piece of music tastes like? Or the color of Tuesday? If the answer is yes, you might be a synesthete. For people with synesthesia, ordinary sensory events, such as listening to music or reading text, elicit experiences involving other senses, such as perceiving a taste or seeing a color. Synesthesia is not to be confused with common metaphors — such as saying someone ‘sees red’ to describe anger. Instead, synesthetic associations are perceptual, highly specific and idiosyncratic, and typically stable beginning in childhood. And many types exist: A taste can have a shape, a word can have a color, the months of the year may be experienced as an array around the body. In the general population, the phenomenon is relatively rare: Only 2 to 4 percent of people have it. But as much as 20 percent of people with autism experience synesthesia1,2. Why would two relatively rare conditions occur together so often? Over the past few years, researchers have found that people with synesthesia or autism share many characteristics. Synesthetes often have sensory sensitivities and attention differences, as well as other autism traits3,4. The two conditions also share brain connectivity patterns and possibly genes, suggesting they have common biological underpinnings. © 2020 Simons Foundation

Keyword: Autism
Link ID: 27304 - Posted: 06.17.2020

By Julia Hollingsworth, CNN (CNN)Laura Molles is so attuned to birds that she can tell where birds of some species are from just by listening to their song. She's not a real-world Dr Doolittle. She's an ecologist in Christchurch, New Zealand, who specializes in a little-known area of science: bird dialects. While some birds are born knowing how to sing innately, many need to be taught how to sing by adults -- just like humans. Those birds can develop regional dialects, meaning their songs sound slightly different depending on where they live. Think Boston and Georgia accents, but for birds. Just as speaking the local language can make it easier for humans to fit in, speaking the local bird dialect can increase a bird's chances of finding a mate. And, more ominously, just as human dialects can sometimes disappear as the world globalizes, bird dialects can be shaped or lost as cities grow. The similarities between human language and bird song aren't lost on Molles -- or on her fellow bird dialect experts. "There are wonderful parallels," said American ornithologist Donald Kroodsma, the author of "Birdsong for the Curious Naturalist: Your Guide to Listening." "Culture, oral traditions -- it's all the same." For centuries, bird song has inspired poets and musicians, but it wasn't until the 1950s that scientists really started paying attention to bird dialects. One of the pioneers of the field was a British-born behaviorist named Peter Marler, who became interested in the subject when he noticed that chaffinches in the United Kingdom sounded different from valley to valley. At first, he transcribed bird songs by hand, according to a profile of him in a Rockefeller University publication. Later, he used a sonagram, which Kroodsma describes on his website as "a musical score for birdsong." ("You really need to see these songs to believe them, our eyes are so much better than our ears," Kroodsma said.) © 2020 Cable News Network.Turner Broadcasting System, Inc.

Keyword: Language; Evolution
Link ID: 27303 - Posted: 06.17.2020

By Laura Sanders The virus responsible for COVID-19 can steal a person’s sense of smell, leaving them noseblind to fresh-cut grass, a pungent meal or even their own stale clothes. But so far, details remain elusive about how SARS-CoV-2, the coronavirus that causes COVID-19, can infiltrate and shut down the body’s smelling machinery. One recent hint comes from a young radiographer who lost her sense of smell. She had signs of viral infection in her brain. Other studies, though, have not turned up signs of the virus in the brain. Contradictory evidence means that no one knows whether SARS-CoV-2 can infect nerve cells in the brain directly, and if so, whether the virus’s route to the brain can sometimes start in the nose. Understanding how people’s sense of smell is harmed (SN: 5/11/20), a symptom estimated to afflict anywhere between 20 and 80 percent of people with COVID-19, could reveal more about how the virus operates. One thing is certain so far, though: The virus can steal the sense of smell in a way that’s not normal. “There’s something unusual about the relationship between COVID-19 and smell,” says neuroscientist Sandeep Robert Datta of Harvard Medical School in Boston. Colds can prevent smelling by stuffing the nose up with mucus. But SARS-CoV-2 generally leaves the nose clear. “Lots of people are complaining about losing their sense of smell when they don’t feel stuffed up at all,” Datta says. © Society for Science & the Public 2000–2020.

Keyword: Chemical Senses (Smell & Taste)
Link ID: 27302 - Posted: 06.13.2020

Natalie Dombois for Quanta Magazine It’s not surprising that the fruit fly larva in the laboratory of Jimena Berni crawls across its large plate of agar in search of food. “A Drosophila larva is either eating or not eating, and if it’s not eating, it wants to eat,” she said. The surprise is that this larva can search for food at all. Owing to a suite of genetic tricks performed by Berni, it has no functional brain. In fact, the systems that normally relay sensations of touch and feedback from its muscles have also been shut down. Berni, an Argentinian neuroscientist whose investigations of fruit fly nervous systems recently earned her a group leader position at the University of Sussex, is learning what the tiny cluster of neurons that directly controls the larva’s muscles does when it’s allowed to run free, entirely without input from the brain or senses. How does the animal forage when it’s cut off from information about the outside world? The answer is that it moves according to a very particular pattern of random movements, a finding that thrilled Berni and her collaborator David Sims, a professor of marine ecology at the Marine Biological Association in Plymouth, U.K. For in its prowl for food, this insensate maggot behaves exactly like an animal Sims has studied for more than 25 years — a shark. In neuroscience, the usual schema for considering behavior has it that the brain receives inputs, combines them with stored information, then decides what to do next. This corresponds to our own intuitions and experiences, because we humans are almost always responding to what we sense and remember. But for many creatures, useful information isn’t always available, and for them something else may also be going on. When searching their environment, sharks and a diverse array of other species, now including fruit fly larvae, sometimes default to the same pattern of movement, a specific type of random motion called a Lévy walk. All Rights Reserved © 2020

Keyword: Learning & Memory; Aggression
Link ID: 27301 - Posted: 06.13.2020

Ruth Williams Research teams in the US and Japan have each discovered independently and by unrelated routes a population of hypothalamic neurons in mice that induce the low body temperature, reduced metabolism, and inactivity characteristic of hibernation and torpor. The two papers are published today (June 11) in Nature. “Trying to pin down which neurons are involved with initiating torpor and hibernation . . . is certainly something that biologists have been interested in for several years now,” says biologist Steven Swoap of Williams College who was not involved in the research. “Both of [the teams] come at it from a different angle and almost end up in the same place, so they complement each other in that way, which is pretty nice,” he adds. Hibernation and daily torpor are both forms of mammalian suspended animation and share a number of features. Both involve significant, but regulated, drops in body temperature, metabolism, heart rate, breathing rate, and activity, and both are thought to be ways of preserving energy when food is scarce. While hibernation lasts for weeks or months, however, daily torpor lasts several hours each day. Why some mammals such as bears and certain primates and rodents have the ability to enter periods of dormancy while others don’t is unknown. But the diversity of hibernator species suggests that the biological mechanisms controlling such states may also be preserved, albeit unused, in non-hibernating species. This tantalizing possibility sparks ideas of sending dormant astronauts on extended space journeys as well as more down-to-earth notions of temporarily lowering body temperature and metabolism to preserve tissues in patients with, for example, traumatic injuries. © 1986–2020 The Scientist.

Keyword: Sleep
Link ID: 27300 - Posted: 06.13.2020

By Sam Roberts Oleh Hornykiewicz, a Polish-born pharmacologist whose breakthrough research on Parkinson’s disease has spared millions of patients the tremors and other physical impairments it can cause, died on May 27 in Vienna. He was 93. His death was confirmed by his longtime colleague, Professor Stephen J. Kish of the University of Toronto, where Professor Hornykiewicz (pronounced whor-nee-KEE-eh-vitch) taught from 1967 until his retirement in 1992. Professor Hornykiewicz was among several scientists who were considered instrumental in first identifying a deficiency of the neurotransmitter dopamine as a cause of Parkinson’s disease, and then in perfecting its treatment with L-dopa, an amino acid found in fava beans. The Nobel laureate Dr. Arvid Carlsson and his colleagues had earlier shown that dopamine played a role in motor function. Drawing on that research, Professor Hornykiewicz and his assistant, Herbert Ehringer, discovered in 1960 that the brains of patients who had died of Parkinson’s had very low levels of dopamine. He persuaded another one of his collaborators, the neurologist Walther Birkmayer, to inject Parkinson’s patients with L-dopa, the precursor of dopamine, which could cross the barrier between blood vessels and the brain and be converted into dopamine by enzymes in the body, thus replenishing those depleted levels. The treatment alleviated symptoms of the disease, and patients who had been bedridden started walking. The initial results of this research were published in 1961 and presented at a meeting of the Medical Society of Vienna. The “L-dopa Miracle,” as it was called, inspired Dr. Oliver Sacks’s memoir “Awakenings” (1973) and the fictionalized movie of the same name in 1990. © 2020 The New York Times Company

Keyword: Parkinsons
Link ID: 27299 - Posted: 06.13.2020

Ruth Williams In the hippocampus of the adult mouse brain, newly formed cells that become activated by a learning experience are later reactivated in the REM phase of sleep, according to a study in Neuron today (June 4). The authors show this reactivation is necessary for fortifying the encoding of the memory. “It is a very cool paper,” writes neuroscientist Sheena Josselyn of the University of Toronto in an email to The Scientist. “This is the first study to causally link new neurons to sleep-dependent memory consolidation. I am sure it will have a broad impact on scientists studying memory, sleep as well as those interested in adult neurogenesis,” she says. Josselyn was not involved in the study. In the adult mammalian brain, most cells do not replicate. But, deep in the center of the organ, in a particular region of the hippocampus called the dentate gyrus, new neurons continue to be born at a slow rate throughout the lifetime of the animal. This neurogenesis is thought to be important for memory formation among other cognitive tasks. Indeed, if the activities of mouse adult-born neurons (ABNs) are perturbed during a learning experience, the animal will not memorize the event as effectively as it does when these cells are left alone. Learning is just one part of forming a memory, however. For memories to last, sleep, and in particular REM sleep, is essential. “Sleep deprivation generally decreases neurogenesis,” writes neuroscientist Masanori Sakaguchi of the International Institute for Integrative Sleep Medicine at the University of Tsukuba in an email to The Scientist. The question was, says Sakaguchi, “is there any function of adult-born neurons during sleep?” To find out, Sakaguchi’s team first examined the activity of mouse ABNs after a learning experience—a contextual fear conditioning in which the animals’ feet were shocked as they explored a particular cage—and during subsequent sleep. Using miniaturized microscopes attached to the skulls of freely moving mice and fluorescent markers to track ABN activities, the team showed that the ABNs that had been activated after the context-shock learning event were more likely to then be reactivated during the animals’ next REM phases of sleep. © 1986–2020 The Scientist

Keyword: Neurogenesis; Sleep
Link ID: 27298 - Posted: 06.10.2020

By Bethany Brookshire Biomedical science has historically been a male-dominated world — not just for the scientists, but also for their research subjects. Even most lab mice were male (SN: 6/18/19). But now, a new study shows that researchers are starting to include more females — from mice to humans — in their work. In 2019, 49 percent of articles surveyed in biomedical science used both male and female subjects, almost twice as many as a decade before, according to findings published June 9 in eLife. A study of articles published in 2009 across 10 biomedical disciplines showed a dismal picture. Only 28 percent of 841 research studies included both males and female subjects. The results were published in 2011 in Neuroscience and Biobehavioral Reviews. The scientific world took note. In 2016, the U.S. National Institutes of Health instituted the Sex as a Biological Variable policy in an effort to correct the imbalance. Scientists had to use both males and females in NIH-funded research unless they could present a “strong justification” otherwise. Annaliese Beery, a neuroscientist at Smith College in Northhampton, Mass., conducted the original study showing the extent of sex bias in research. In 2019, she and Nicole Woitowich, a chemist at Northwestern University in Evanston, Ill., wanted to see if sex bias was still as strong as it was in 2009. Have things improved? After scanning another 720 articles across nine of the 10 original disciplines, the researchers have shown that yes, they have, with nearly half of all journal articles including both males and females. Behavioral research was the most inclusive, with both sexes in 81 percent of studies. Overall, six out of nine fields surveyed showed a significant increase in studies that included both sexes. © Society for Science & the Public 2000–2020

Keyword: Sexual Behavior
Link ID: 27297 - Posted: 06.10.2020