…but has yet to reach Base Camp 1 By Gary Stix LONG ISLAND, N.Y.—Brains & Behavior,* a conference at Cold Spring Harbor Laboratory (CSHL) held from May 30 to June 4—furnished a captivating look at the work of neuroscientists toiling to isolate the multitude of missing links that bind B&B. Of course, everyone knows about the close ties between the two, but generation after generation of researchers will be needed toto figure out the how of it all. At the end of the conference, Adam Kepecs, a CSHL researcher who had given a talk about his lab’s work on how the brain computes confidence in its own decision-making, summarized several emerging themes to be derived from the conference—novel technologies driving progress in the field and the conversion of some basic research into treatments—not just pharmaceuticals but technologies such as electrical stimulation of the brain. The still relatively slow pace toward clinical trials follows from the size of the challenge. “Understanding the brain functionally—and its dysfunctions—is arguably one of the greatest challenges of humanity,” Kepecs said. CSHL asked me to interview three of the presenters for the lab’s YouTube channel, CSHL Leading Strand. The videos, just a few of those from the conference on the lab’s channel, provide more detail about what the scientists there are up to—and the halting steps toward that initial base camp. There was Li-Huei Tsai of Massachusetts Institute of Technology’s Picower Institute for Learning and Memory who talked to me about using noninvasive, flickering light that alters brain rhythms to potentially aid Alzheimer’s patients. Ricardo Dolmetsch, global head of neuroscience with the Novartis Institutes for Biomedical Research, recounted the development of a gene therapy for spinal muscular atrophy. And Robert Malenka, a professor of psychiatry at Stanford University Medical School continues to investigate a brain pathway that promotes social interactions—as well as the street drug, MDMA (aka ecstasy), which enhances prosocial behavior, also through its actions on the neurotransmitter serotonin. © 2018 Scientific American

Keyword: Miscellaneous
Link ID: 25063 - Posted: 06.07.2018

By Douglas Woods It often starts with a simple, subtle behavior like a rapid eye blink. Sometimes it’s a nose-scrunch or a sniff that is confused with a lingering cold or an allergy. Often, these habits go away on their own, but in about 1 percent of children (boys more so than girls), these blinks, twitches, and coughs become the persistent tic disorder known as Tourette syndrome (TS), a misunderstood and stigmatizing neurological condition. Media portrayals of TS often overemphasize the rare (fewer than 15 percent of cases) symptoms, in which people with TS shout obscene words—a symptom known as coprolalia—but most patients have a wide range of movements and sounds, ranging from simple tics to more complex ones that often look intentional but are not. Hidden beneath the tics, people with TS often experience "premonitory urges”—unpleasant sensations that build until the tic occurs. Ticcing brings a brief sense of relief, but the urges soon return. We know that TS is a genetically-based neurological disorder that is strongly influenced by a person’s surroundings. The disorder stems from a problem within the basal ganglia, a series of structures in the brain that are responsible for selecting and inhibiting our movements. When neurons fire, signaling us to move, the basal ganglia serves as a filter, allowing some of these signals to pass through and become movements. Other movement signals that are not needed in a particular situation are held back. © 2018 Scientific American

Keyword: Tourettes; Learning & Memory
Link ID: 25062 - Posted: 06.06.2018

By Ingfei Chen Each year, according to the U.S. Department of Agriculture, roughly 820,800 guinea pigs, dogs, cats, and other animals covered by the Animal Welfare Act are used in research in the U.S.; of those, about 71,370 are subjected to unalleviated pain. These stats don’t track the millions of mice and rats that are used in lab experiments and excluded from the animal protection law (although the rodents are covered by other federal regulations). Scientists and their institutions say they’re committed to keeping pain or distress to a minimum in lab animals where they can. But how do you know how much pain a mouse or a zebrafish feels? And who decides how much pain is too much? “We know if they’re in really bad pain, as much as they want a nice nest, they’re not gonna put the work into doing that.” The issue of animal suffering was in the headlines earlier this year, when landlocked Switzerland banned the culinary practice of boiling lobsters alive. No one knows for sure whether these big-clawed crustaceans, equipped with only a rudimentary nervous system, experience pain. Nonetheless, Swiss authorities now require stunning lobsters in a humane way before tossing them into the pot. I read of this milestone in crustacean rights with bemused fascination and anthropomorphic cringing, as I imagined the lobster’s hypothetical plight. But the Swiss move also made me wonder how scientists measure and deal with animal pain in research studies. Experiments that use critters to simulate human illness or injury are stepping stones to the medical treatments we all use. Yet, the benefits we reap must outweigh the costs to animal welfare for those sacrifices to be justified, ethicists and animal advocates say. Copyright 2018 Undark

Keyword: Animal Rights; Pain & Touch
Link ID: 25061 - Posted: 06.06.2018

Emine Saner One of the fun parts of being a disgustologist – as researchers who study the emotion of disgust sometimes call themselves – must be coming up with revolting scenarios. Repulsive enough to test a theory, but not quite so stomach-turning as to repel the people who have volunteered to take the test. In a recent study led by Prof Val Curtis, director of the environmental health group at the London School of Hygiene and Tropical Medicine, the vignettes were admirably imaginative. People were asked to rate their levels of disgust at more than 70 scenarios. These included imagining a hairless old cat rubbing up against one’s leg, stepping on a slug in bare feet, shaking hands with someone with “scabby fingers”, finding out a friend eats roadkill, finding out another attempted to have sex with a piece of fruit, and seeing “pus come from a genital sore”. And, my personal favourite, for warped imagination alone: learning your neighbour defecates in his back garden. The findings, published this week in the Royal Society’s Philosophical Transactions B journal, reveal six categories of disgust: poor hygiene, animals that are vectors of disease (such as rats or cockroaches), sexual behaviours, atypical appearance, lesions and visible signs of infection, and food that shows signs of decay. “The fact we’ve found there is an architecture of disgust that has six components to it tells us something about the way in which emotions work,” says Curtis. “It tells us that emotions are for doing particular behaviours. The emotion of disgust is about doing certain things that avoid disease – they’re about not eating spoiled food, not sticking your fingers in somebody’s weeping sore, not having sex with somebody you know is having sex with lots of other people, not picking up cockroaches and kissing them. It confirms the hypothesis that disgust really is about avoiding infection.” © 2018 Guardian News and Media Limited

Keyword: Emotions
Link ID: 25060 - Posted: 06.06.2018

By Ruth Williams Four patients with chronic spinal damage and a complete loss of motor and sensory functions below their waists have received transplants of human neural stem cells in a first-of-its-kind clinical trial. A report in Cell Stem Cell today (June 1) documents the procedure and the subsequent clinical follow up of the patients, who exhibit no signs of untoward effects but rather tiny hints of improvement. “It’s an extremely interesting and important piece of work,” says neurologist Eva Feldman of the University of Michigan who was not involved with the work. “The rodent model results were very compelling and . . . laid the groundwork for this very small, proof-of-concept safety trial.” While these results seem tantalizing, “the numbers [of patients] are extremely small,” says Feldman, and “the patients themselves notice no change in function or quality of life.” Severe spinal injuries can have devastating consequences, often leaving patients with complete paralysis below the injury site and with little hope of recovery. While there is currently no therapy that can promote neuronal repair in such patients, evidence from animal studies, including those carried out in primates, has indicated that transplantation of human-derived neural stem cells to the site of injury can promote some functional recovery of downstream musculature. © 1986-2018 The Scientist

Keyword: Regeneration; Stem Cells
Link ID: 25059 - Posted: 06.05.2018

Sheryl Ubelacker · A little over a year ago, Julie Tomaino had a stroke that affected both sides of her brain, leaving her "locked in" — conscious but unable to speak or move — for about 10 days. The former professional dancer who works in theatre directing and choreographing plays was just 38 years old. "I couldn't respond to anything and I could just move my eyeballs," the Toronto resident recalled Monday from Vancouver Island, where she is in rehearsals for a production of the musical Grease. Tomaino had been having daily headaches for two weeks and knew there was something seriously wrong. But after examining her earlier that day at the hospital, doctors had sent her home with a diagnosis of migraine and anxiety. That evening, she started vomiting uncontrollably and began experiencing double vision. Her husband called an ambulance and she remembers being put into the vehicle. "And then it's all black for 12 hours." Tomaino had suffered a major stroke, the result of the inner carotid arteries on both sides of her neck dissecting, or tearing, which caused blood to pool in the vessels and send clots to her brain. While stroke at her age isn't all that common — the average female victim is close to four decades older — her story illustrates a message the Heart and Stroke Foundation is trying to bring to public awareness with a report released Tuesday showing how stroke can affect women differently than men. ©2018 CBC/Radio-Canada

Keyword: Stroke; Sexual Behavior
Link ID: 25058 - Posted: 06.05.2018

By Randi Hutter Epstein My son Jack was born in London a month before his due date. The pediatrician said he was fine and we could go home. A few minutes later another doctor came in and asked to draw blood to try to figure out why Jack was premature. I refused, because we had already been given the go-ahead to leave. I heard the doctor tell the nurses to mark in my medical record, “Mother refuses treatment for her son.” “I’m not refusing treatment! I’m refusing a needless test!” I said from my bed. To which she mumbled, “Write down, ‘Mother is hormonal.’” And so began my rant. I stormed out of my room, dressed only in my husband’s white T-shirt and nestling my 12-hour-old son to my chest, and hollered after the fleeing doctor, “I am not hormonal!” The truth is I was hormonal. I had just given birth, so my progesterone (the hormone that maintained my pregnancy) had plummeted and my oxytocin (the hormone that squeezed my uterus to get the baby out, got the milk flowing and fostered mother-baby bonding) had skyrocketed. But that’s not what the doctor meant when she used the word “hormonal.” She meant I was a woman going off the rails. In 1939, James E. King, the president of the American Association of Obstetricians, Gynecologists and Abdominal Surgeons, devoted part of his presidential address to hormones and women’s craziness, or as he called it, their “peculiarities” and “inconsistencies.” He said hormone therapy, which was brand new at the time, would not only treat conditions like menstrual irregularities and infertility but would also help women manage their emotions and make them prettier (estrogen would supposedly bring back aging women’s youthful splendor). Then he concluded with this snide remark: “Will she, as some timid souls fear, mentally and physically dominate and enslave us as we in the past enslaved her? Probably not; so long as she is controlled by her reproductive glands, she will remain basically the same lovable and gracious homemaker.” © 2018 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 25057 - Posted: 06.05.2018

By The Editorial Board When President Trump mused that the mass shooting at a high school in Parkland, Fla., in February might have been prevented if the United States had more mental institutions, he revived a not-quite-dormant debate: Should the country bring back asylums? Psychiatric facilities are unlikely to prevent crimes similar to the Parkland shooting because people are typically not committed until after a serious incident. Still, a string of news articles, editorials and policy forums have noted that plenty of mental health experts agree with the president’s broader point. The question of whether to open mental institutions tends to divide the people who provide, use and support mental health services — let’s call them the mental health community — into two camps. There are just 14 or so psychiatric beds per every 100,000 people in the United States, a 95 percent decline from the 1950s. One camp says this profound shortage is a chief reason that so many people suffering from mental health conditions have ended up in jail, on the streets or worse. The other argues that large psychiatric institutions are morally repugnant, and that the problem is not the lack of such facilities but how little has been done to fill the void since they were shut down. Neither side wants to return to the era of “insane asylums,” the warehouselike hospitals that closed en masse between the 1960s and 1980s. Nor does anyone disagree that the “system” that replaced them is a colossal failure. Nearly 10 times as many people suffering from serious mental illnesses are being kept in jails and prisons as are receiving treatment in psychiatric hospitals. What’s more, both sides broadly agree that mental institutions alone would not be the solution. “Bring back the asylums” sounds catchy, but here are some more useful slogans to help steer the conversation: © 2018 The New York Times Company

Keyword: Schizophrenia; Aggression
Link ID: 25056 - Posted: 06.04.2018

By David Noonan Neuroscientist James Hudspeth has basically been living inside the human ear for close to 50 years. In that time Hudspeth, head of the Laboratory of Sensory Neuroscience at The Rockefeller University, has dramatically advanced scientists’ understanding of how the ear and brain work together to process sound. Last week his decades of groundbreaking research were recognized by the Norwegian Academy of Science, which awarded him the million-dollar Kavli Prize in Neuroscience. Hudspeth shared the prize with two other hearing researchers: Robert Fettiplace from the University of Wisconsin–Madison and Christine Petit from the Pasteur Institute in Paris. Advertisement As Hudspeth explored the neural mechanisms of hearing over the years, he developed a special appreciation for the intricate anatomy of the inner ear—an appreciation that transcends the laboratory. “I think we as scientists tend to underemphasize the aesthetic aspect of science,” he says. “Yes, science is the disinterested investigation into the nature of things. But it is more like art than not. It’s something that one does for the beauty of it, and in the hope of understanding what has heretofore been hidden. Here’s something incredibly beautiful, like the inner ear, performing a really remarkable function. How can that be? How does it do it?” After learning of his Kavli Prize on Thursday, Hudspeth spoke with Scientific American about his work and how the brain transforms physical vibration into the experience of a symphony. © 2018 Scientific American

Keyword: Hearing
Link ID: 25055 - Posted: 06.04.2018

Jon Hamilton For six years now, life has been really good for James. He's got a great job as the creative director of an advertising firm in New York City. He enjoys spending time with his wife and kids. And it's all been possible, he says, because for the past six years he's been taking a drug called ketamine. Before ketamine, James was unable to work or focus his thoughts. His mind was filled with violent images. And his mood could go from ebullient to dark in a matter of minutes. Ketamine "helped me get my life back," says James, who asked that we not use his last name to protect his career. Ketamine was developed as a human and animal anesthetic in the 1960s. And almost from the time it reached the market it's also been used as a mind-bending party drug. But ketamine's story took a surprising turn in 2006, when researchers at the National Institutes of Health showed that an intravenous dose could relieve severe depression in a matter of hours. Since then, doctors have prescribed ketamine "off label" to thousands of depressed patients who don't respond to other drugs. And pharmaceutical companies are testing several new ketamine-related drugs to treat depression. Johnson & Johnson expects to seek approval for its nasal spray esketamine later this year. Meanwhile, doctors have begun trying ketamine on patients with a wide range of psychiatric disorders other than depression. And there is now growing evidence it can help people with anxiety, bipolar disorder, post-traumatic stress disorder, and perhaps even obsessive-compulsive disorder. © 2018 npr

Keyword: Depression; Drug Abuse
Link ID: 25054 - Posted: 06.04.2018

Davide Castelvecchi The 2016 film Arrival starred Amy Adams as a linguistics professor who was drafted in to communicate with aliens.Credit: Moviestore Coll./Alamy Sheri Wells-Jensen is fascinated by languages no one has ever heard — those that might be spoken by aliens. Last week, the linguist co-hosted a day-long workshop on this field of research, which sits at the boundary of astrobiology and linguistics. The meeting, at a conference of the US National Space Society in Los Angeles, California, was organized by Messaging Extraterrestrial Intelligence (METI). METI, which is funded by private donors, organizes the transmission of messages to other star systems. The effort is complementary to SETI (Search for Extraterrestrial Intelligence), which aims to detect messages from alien civilizations. METI targets star systems relatively close to the Sun that are known to host Earth-sized planets in their ‘habitable zone’ — where the conditions are right for liquid water to exist — using large radar dishes. Last year, it directed a radio message, which attempted to explain musical language, towards a nearby exoplanet system. The message started from basic arithmetic (encoded in binary as two radio wavelengths) and introduced increasingly complex concepts such as duration and frequency. Nature spoke to Wells-Jensen, who is a member of METI’s board of directors, about last week’s meeting and the field of alien linguistics. Was this the first workshop of this kind ever? We’ve done two workshops on communicating with aliens before, but this is the first one specifically about linguistics. If we do make contact, we should try and figure out what would be a reasonable first step in trying to communicate. Right now, we are trying to put our heads together and figure out what’s likely and what could be done after that. © 2018 Macmillan Publishers Limited,

Keyword: Language; Animal Communication
Link ID: 25053 - Posted: 06.04.2018

By Ruth Williams The sun’s ultraviolet (UV) radiation is a major cause of skin cancer, but it offers some health benefits too, such as boosting production of essential vitamin D and improving mood. Today (May 17), a report in Cell adds enhanced learning and memory to UV’s unexpected benefits. Researchers have discovered that, in mice, exposure to UV light activates a molecular pathway that increases production of the brain chemical glutamate, heightening the animals’ ability to learn and remember. “The subject is of strong interest, because it provides additional support for the recently proposed theory of ultraviolet light’s regulation of the brain and central neuroendocrine system,” dermatologist Andrzej Slominski of the University of Alabama who was not involved in the research writes in an email to The Scientist. “It’s an interesting and timely paper investigating the skin-brain connection,” notes skin scientist Martin Steinhoff of University College Dublin’s Center for Biomedical Engineering who also did not participate in the research. “The authors make an interesting observation linking moderate UV exposure to . . . [production of] the molecule urocanic acid. They hypothesize that this molecule enters the brain, activates glutaminergic neurons through glutamate release, and that memory and learning are increased.” © 1986-2018 The Scientist

Keyword: Learning & Memory; Biological Rhythms
Link ID: 25052 - Posted: 06.02.2018

Will Stone Hundreds of survivors of domestic violence have come through the doors of neurologist Glynnis Zieman's Phoenix clinic in the past three years. "The domestic violence patients are the next chapter of brain injury," she says. Zieman begins every new patient visit with a simple question: "What are the symptoms you hope I can help you with?" For most, it's the first time anyone has ever asked even how they may have been injured in the first place. "I actually heard one patient tell me the only person who ever asked her if someone did this to her was a paramedic, as she was being wheeled into an ambulance," Zieman says. "And the husband was at the foot of her stretcher." While many patients initially seek out the clinic because of physical symptoms, such as headaches, exhaustion, dizziness or problems sleeping, Zieman says her research shows anxiety, depression and PTSD usually end up being the most severe problems. Studies of traumatic brain injury have revealed links to dementia and memory loss in veterans and athletes. And TBI has also been linked to PTSD in current or former service members. Another group may be suffering, still largely in silence — survivors of domestic violence. About 70 percent of people seen in the ER for such abuse are never actually identified as survivors of domestic violence. It's a health crisis cloaked in secrecy and shame, one that Zieman is uncovering through her work at the Barrow Concussion and Brain Injury Center. © 2018 npr

Keyword: Brain Injury/Concussion; Aggression
Link ID: 25051 - Posted: 06.02.2018

By Matt Warren Scientists regularly comb through 3D data, from medical images to maps of the moon, yet they are often stuck using flat computer screens that can’t fully represent 3D data sets. Now, researchers have developed a method of 3D printing that lets scientists produce stunning, high-definition 3D copies of their data. Conventional 3D-printing converts data into a computer model made up of tiny, connected triangles. But this process can create awkward images: The fine lines of the brain’s white matter, for example, show up as bulky tubes. Conventional printing also has problems creating objects where solid parts (or data points) are separated by empty space. The new process is far more direct. Instead of transforming into a computer model, the data set is sliced up into thousands of horizontal images, each consisting of hundreds of thousands of voxels, or 3D pixels. Each voxel is printed with droplets of colored resin hardened by ultraviolet light. Different colors can be combined to create new ones, and transparent resin is used to represent empty space. Each layer is printed, one on top of another, to gradually build up a 3D structure. So far, the researchers have used the voxel printing process to produce high-definition models of brain scans, topographical maps, and laser-scanned statues. And although it may take some time to get there, the team sees a day when anyone will be able to print off a copy of their data at the press of a button, from archaeologists reproducing important artifacts for conservation to doctors creating models of body parts to plan surgical procedures. Posted in: © 2018 American Association for the Advancement of Science.

Keyword: Brain imaging
Link ID: 25050 - Posted: 06.02.2018

Aimee Cunningham Opioids have quickly become a major cause of death among young Americans aged 25 to 34, with one in five deaths in 2016 tied to the drugs, researchers report online June 1 in JAMA Open Network. That’s a steep rise from 2001, when opioids accounted for 4 percent of all deaths in that age group. The second-most affected age group was 15-24, for whom 12 percent of all deaths in 2016 were attributed to opioid overdoses, according to data from the Centers for Disease Control and Prevention. It’s the younger populations “where we really see this huge contribution of opioid overdoses,” says epidemiologist and study coauthor Tara Gomes of St. Michael’s Hospital in Toronto. “We’re losing so much potential life.” |© Society for Science & the Public 2000 - 2018

Keyword: Drug Abuse
Link ID: 25049 - Posted: 06.02.2018

By Robert F. Service Prosthetics may soon take on a whole new feel. That’s because researchers have created a new type of artificial nerve that can sense touch, process information, and communicate with other nerves much like those in our own bodies do. Future versions could add sensors to track changes in texture, position, and different types of pressure, leading to potentially dramatic improvements in how people with artificial limbs—and someday robots—sense and interact with their environments. “It’s a pretty nice advance,” says Robert Shepherd, an organic electronics expert at Cornell University. Not only are the soft, flexible, organic materials used to make the artificial nerve ideal for integrating with pliable human tissue, but they are also relatively cheap to manufacture in large arrays, Shepherd says. Modern prosthetics are already impressive: Some allow amputees to control arm movement with just their thoughts; others have pressure sensors in the fingertips that help wearers control their grip without the need to constantly monitor progress with their eyes. But our natural sense of touch is far more complex, integrating thousands of sensors that track different types of pressure, such as soft and forceful touch, along with the ability to sense heat and changes in position. This vast amount of information is ferried by a network that passes signals through local clusters of nerves to the spinal cord and ultimately the brain. Only when the signals combine to become strong enough do they make it up the next link in the chain. © 2018 American Association for the Advancement of Science.

Keyword: Robotics; Pain & Touch
Link ID: 25048 - Posted: 06.01.2018

By Maggie Koerth-Baker If an animal is smart enough, should we treat it like a human? An abstract question, but one that found its way into a courtroom recently. A case bidding for consideration by the New York State Court of Appeals sought to extend the legal concept of habeas corpus — which allows a person to petition a court for freedom from unlawful imprisonment — to cover two privately-owned chimpanzees. The case for giving the chimps a human right like freedom from unlawful incarceration is based on their similarity to humans — they can think, feel and plan, argue the people bringing the case on behalf of the chimpanzees, so shouldn’t they have some guarantees of liberty? The court declined to hear the case, but one judge did say that some highly intelligent animals probably should be treated more like people and less like property. It’s just one judge, but you hear this kind of thing a lot from animal rights activists. The Nonhuman Rights Project, the nonprofit behind the habeas corpus lawsuit, has a stated goal of securing increased, human-like rights for great apes, elephants, dolphins and whales — highly intelligent, charismatic mammals. So, does a chimpanzee deserve more rights than, say, a pigeon? The logic that leads to “yes” is clear enough, but putting it into practice would be tough, scientists say. Because when it comes to measuring intelligence, we’re actually a little dumb. One of the problems: Animals don’t stack up the way you’d expect. “[Pigeons have] knocked our socks off in our own lab and other people’s labs in terms of what they can do,” said Edward Wasserman, a professor of experimental psychology at the University of Iowa. “Pigeons can blow the doors off monkeys in some tasks.” Experts who study animal intelligence across species say we can’t rank animals by their smarts — scientists don’t even try anymore — which means there’s no objective way to determine which animals would deserve more human-like rights.

Keyword: Evolution; Animal Rights
Link ID: 25047 - Posted: 06.01.2018

By Elizabeth Pennisi Three nearly identical genes could help explain how 0.5 liters of gray matter in early human ancestors became the 1.4-liter organ that has made our species so successful and distinctive. The newly identified genes could also help explain how brain development sometimes goes wrong, leading to neurological disorders. The genes, descendants of an ancient developmental gene that multiplied and changed in the course of evolution, add to a growing list of DNA implicated in human brain expansion. But they stand out because so much has been learned about how they work their magic, says James Noonan, an evolutionary genomicist at Yale University. Researchers have shown that this trio boosts the number of potential nerve cells in brain tissue, and one team even pinned down the protein interactions likely responsible. “These are new proteins that are potentially modifying a very important pathway in brain development in a very powerful way,” Noonan adds. Until now, the four genes were thought to be one, NOTCH2NL, itself a spinoff of the NOTCH gene family, which controls the timing of development in everything from fruit flies to whales. But two studies in the 31 May issue of Cell trace a series of genetic accidents in recent evolutionary history that have yielded four very closely related NOTCH2NL genes in humans (see graphic, below). David Haussler, a bioinformatician at the University of California, Santa Cruz, and his colleagues got on the trail of the genes after they discovered that the NOTCH pathway works differently in human and macaque brain organoids—test tube models of the developing brain. NOTCH2NL was missing in the macaque organoid and, later analyses showed, in other nonhuman apes as well. That suggested NOTCH2NL might have played a unique role in human evolution. © 2018 American Association for the Advancement of Science.

Keyword: Evolution; Development of the Brain
Link ID: 25046 - Posted: 06.01.2018

Some human brains are nearly twice the size of others – but how might that matter? Researchers at the National Institute of Mental Health (NIMH) and their NIH grant-funded colleagues have discovered that these differences in size are related to the brain’s shape and the way it is organized. The bigger the brain, the more its additional area is accounted for by growth in thinking areas of the cortex, or outer mantle – at the expense of relatively slower growth in lower order emotional, sensory, and motor areas. This mirrors the pattern of brain changes seen in evolution and individual development – with higher-order areas showing greatest expansion. The researchers also found evidence linking the high-expanding regions to higher connectivity between neurons and higher energy consumption. “Just as different parts are required to scale-up a garden shed to the size of a mansion, it seems that big primate brains have to be built to different proportions,” explained Armin Raznahan, M.D., Ph.D., of the NIMH Intramural Research Program (IRP). “An extra investment has to be made in the part that integrates information – but that’s not to say that it’s better to have a bigger brain. Our findings speak more to the different organizational needs of larger vs. smaller brains.” Raznahan, P.K. Reardon, Jakob Seidlitz, and colleagues at more than six collaborating research centers report on their study incorporating brain scan data from more than 3,000 people in Science. Reardon and Seidlitz are students in the NIH Oxford-Cambridge Scholars Program.

Keyword: Attention; Evolution
Link ID: 25045 - Posted: 06.01.2018

By Carl Zimmer Early inhabitants of the Americas split into two populations over 13,000 years ago, according to a new study of ancient DNA, and remained separated for thousands of years. Eventually, somewhere, the two groups met again and began commingling. Today, their descendants inhabit a vast region stretching from Mexico to the southern tip of South America. The research, published on Thursday in the journal Science, paints a complex picture of human migrations through the Americas. When people arrived in the Western Hemisphere from Asia, they didn’t just move to new territories and settle down. “This study is important because it begins to move us away from overly simplistic models of how people first spread throughout the Americas,” said Deborah A. Bolnick, a geneticist at the University of Texas at Austin, who was not involved in the study. The findings emerged from a study of 91 ancient genomes of people who lived as long as 4,800 years ago in what are now Alaska, California and Ontario. They represent a major addition to the catalog of ancient DNA in the Western Hemisphere. Until the 1990s, archaeological sites provided much of the evidence for the spread of people across the Americas. There’s firm archaeological evidence that people had reached southern Chile by 14,500 years ago, for example; some researchers even argue that people arrived several thousand years earlier. Yet archaeology alone has left many questions unanswered, such as who exactly lived in those early sites and how they were related to each other. Geneticists are seeking to answer some of those questions by looking at the DNA of living Native Americans. Early studies on small fragments of genes suggested that all Native Americans south of the Arctic descended from the same group of migrants, who may have traveled across the Bering Land Bridge connecting Asia to what is now Alaska at the end of the last ice age. © 2018 The New York Times Company

Keyword: Evolution
Link ID: 25044 - Posted: 06.01.2018