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By Abby Phillip You know the ones: They seem to be swaying to their own music or clapping along to a beat only they can hear. You may even think that describes you. The majority of humans, however, do this very well. We clap, dance, march in unison with few problems; that ability is part of what sets us apart from other animals. But it is true that rhythm — specifically, coordinating your movement with something you hear — doesn't come naturally to some people. Those people represent a very small sliver of the population and have a real disorder called "beat deafness." Unfortunately, your difficulty dancing or keeping time in band class probably doesn't quite qualify. A new study by McGill University researchers looked more closely at what might be going on with "beat deaf" individuals, and the findings may shed light on why some people seem to be rhythm masters while others struggle. Truly beat deaf people have a very difficult time clapping or tapping to an auditory beat or swaying to one. It's a problem that is far more severe than a lack of coordination. And it isn't attributable to motor skills, hearing problems or even a person's inability to create a regular rhythm. Illustrating how rare the disorder really is, McGill scientists received hundreds of inquiries from people who thought they were beat deaf, but only two qualified as having truly severe problems.

Keyword: Hearing
Link ID: 20304 - Posted: 11.13.2014

By Jia You Like humans, flies are attracted to alcohol. Fruit flies (Drosophila melanogaster, above) prefer to lay their eggs on rotten food that can contain ethanol in as high as 7% concentration. (That’s 14 proof to you bar hoppers.) And just like people, the insects differ in their ability to hold their drinks. Biologists know that compared with flies from tropical Africa, flies from temperate regions such as Europe survive longer when exposed to ethanol vapors of high concentrations, and they know it has something to do with enzymes on the flies’ second chromosomes, which break down alcohol and are more active in European flies. But now, biologist James Fry of the University of Rochester in New York has pinpointed a missing piece of the story: the role played by the flies’ third chromosomes. After studying flies collected from Vienna and Cameroon, Fry found that the Vienna flies break down alcohol much faster than Cameroon ones, as expected. But when he replaced the third chromosomes in Cameroon flies with those from Vienna, the African flies gained much more resistance, Fry reports online today in The Journal of Experimental Biology. In a specialized population of flies that could not detoxify alcohol, however, the genetic engineering made no difference whatsoever. Fry suggests that’s because the third chromosomes in European flies help them tolerate acetic acid, a byproduct of internal alcohol breakdown that also gives vinegar its sour taste. There’s no telling what the acetic acid does to the flies, but previous studies on mice have found that it may be responsible for hangover headaches, Fry says. © 2014 American Association for the Advancement of Science

Keyword: Drug Abuse; Aggression
Link ID: 20303 - Posted: 11.13.2014

By JAMES GORMAN Research on the brain is surging. The United States and the European Union have launched new programs to better understand the brain. Scientists are mapping parts of mouse, fly and human brains at different levels of magnification. Technology for recording brain activity has been improving at a revolutionary pace. The National Institutes of Health, which already spends $4.5 billion a year on brain research, consulted the top neuroscientists in the country to frame its role in an initiative announced by President Obama last year to concentrate on developing a fundamental understanding of the brain. Scientists have puzzled out profoundly important insights about how the brain works, like the way the mammalian brain navigates and remembers places, work that won the 2014 Nobel Prize in Physiology or Medicine for a British-American and two Norwegians. So many large and small questions remain unanswered. How is information encoded and transferred from cell to cell or from network to network of cells? Science found a genetic code but there is no brain-wide neural code; no electrical or chemical alphabet exists that can be recombined to say “red” or “fear” or “wink” or “run.” And no one knows whether information is encoded differently in various parts of the brain. Brain scientists may speculate on a grand scale, but they work on a small scale. Sebastian Seung at Princeton, author of “Connectome: How the Brain’s Wiring Makes Us Who We Are,” speaks in sweeping terms of how identity, personality, memory — all the things that define a human being — grow out of the way brain cells and regions are connected to each other. But in the lab, his most recent work involves the connections and structure of motion-detecting neurons in the retinas of mice. Larry Abbott, 64, a former theoretical physicist who is now co-director, with Kenneth Miller, of the Center for Theoretical Neuroscience at Columbia University, is one of the field’s most prominent theorists, and the person whose name invariably comes up when discussions turn to brain theory. © 2014 The New York Times Company

Keyword: Brain imaging
Link ID: 20302 - Posted: 11.11.2014

Mo Costandi The father of modern neuroscience had a sharp eye and an even sharper mind, but he evidently overlooked something rather significant about the basic structure of brain cells. Santiago Ramón y Cajal spent his entire career examining and comparing nervous tissue from different species. He observed the intricate branches we now call dendrites, and the thicker axonal fibres. He also recognised them as distinct components of the neuron, and convinced others that neurons are fundamental components of the nervous system. For Cajal, these cells were “the mysterious butterflies of the soul… whose beating of wings may one day reveal to us the secrets of the mind.” He hunted for them in “the gardens of the grey matter” and, being an accomplished artist, meticulously catalogued the many “delicate and elaborate forms” that they take. As his beautiful drawings show, all neurons have a single axon emanating from one area of the cell body, and one or more dendrites arising from another. This basic structure has been enshrined in textbooks ever since. But there appear to be unusual varieties of soul butterflies that Cajal failed to spot – neuroscientists in Germany have identified neurons that have axons growing from their dendrites, a discovery that challenges our century-old assumption about the form and function of these cells. Cajal stated that information flows through neurons in only one direction – from the dendrites, which receive electrical impulses from other neurons, to the cell body, which processes the information and conveys it to the initial segment of the axon, which then produces its own impulses that travel down it to the nerve terminal. (He indicated this with small arrows in some of his diagrams, such as the one above.) © 2014 Guardian News and Media Limited

Keyword: Brain imaging
Link ID: 20301 - Posted: 11.11.2014

By Julia Calderone Antidepressant use among Americans is skyrocketing. Adults in the U.S. consumed four times more antidepressants in the late 2000s than they did in the early 1990s. As the third most frequently taken medication in the U.S., researchers estimate that 8 to 10 percent of the population is taking an antidepressant. But this spike does not necessarily signify a depression epidemic. Through the early 2000s pharmaceutical companies were aggressively testing selective serotonin reuptake inhibitors (SSRIs), the dominant class of depression drug, for a variety of disorders—the timeline below shows the rapid expansion of FDA-approved uses. As the drugs' patents expired, companies stopped funding studies for official approval. Yet doctors have continued to prescribe them for more ailments. One motivating factor is that SSRIs are a fairly safe option for altering brain chemistry. Because we know so little about mental illness, many clinicians reason, we might as well try the pills already on the shelf. Doctors commonly use antidepressants to treat many maladies they are not approved for. In fact, studies show that between 25 and 60 percent of prescribed antidepressants are actually used to treat nonpsychological conditions. The most common and well-supported off-label uses of SSRIs include: Abuse and dependence ADHD (in children and adolescents) Anxiety disorders Autism (in children) Bipolar disorder Eating disorders Fibromyalgia Neuropathic pain Obsessive-compulsive disorder Premenstrual dysphoric disorder © 2014 Scientific American

Keyword: Depression
Link ID: 20300 - Posted: 11.11.2014

By Abby Phillip If you're confused about what marijuana use really does to people who use it, you're not alone. For years, the scientific research on health effects of the drug have been all over the map. Earlier this year, one study suggested that even casual marijuana use could cause changes to the brain. Another found that marijuana use was also associated with poor sperm quality, which could lead to infertility in men. But marijuana advocates point to other research indicating that the drug is far less addictive than other drugs, and some studies have found no relationship between IQ and marijuana use in teens. Researchers at the Center for Brain Health at the University of Texas in Dallas sought to clear up some of the confusion with a study that looked at a relatively large group of marijuana users and evaluated their brains for a slew of different indicators. What they found was complex, but the pattern was clear: The brains of marijuana users were different than those of non-marijuana users. The area of the brain responsible for establishing the reward system that helps us survive and also keeps us motivated was smaller in users than in non-marijuana users. But there was also evidence that the brain compensated for this loss of volume by increasing connectivity and the structural integrity of the brain tissue. Those effects were more pronounced for marijuana users who started young. "The orbitofrontal cortex is one of the primary regions in a network of brain areas called the reward system," explained Francesca Filbey, lead author of the study and an associate professor of the neurogenetics of addictive behavior at the University of Texas in Dallas. "

Keyword: Drug Abuse; Aggression
Link ID: 20299 - Posted: 11.11.2014

Email David By David Grimm Place a housecat next to its direct ancestor, the Near Eastern wildcat, and it may take you a minute to spot the difference. They’re about the same size and shape, and, well, they both look like cats. But the wildcat is fierce and feral, whereas the housecat, thanks to nearly 10,000 years of domestication, is tame and adaptable enough to have become the world’s most popular pet. Now scientists have begun to pinpoint the genetic changes that drove this remarkable transformation. The findings, based on the first high-quality sequence of the cat genome, could shed light on how other creatures, even humans, become tame. “This is the closest thing to a smoking gun we’ve ever had,” says Greger Larson, an evolutionary biologist at the University of Oxford in the United Kingdom who has studied the domestication of pigs, dogs, and other animals. “We’re much closer to understanding the nitty-gritty of domestication than we were a decade ago.” Cats first entered human society about 9500 years ago, not long after people first took up farming in the Middle East. Drawn to rodents that had invaded grain stores, wildcats slunk out of the deserts and into villages. There, many scientists suspect, they mostly domesticated themselves, with the friendliest ones able to take advantage of human table scraps and protection. Over thousands of years, cats shrank slightly in size, acquired a panoply of coat colors and patterns, and (largely) shed the antisocial tendencies of their past. Domestic animals from cows to dogs have undergone similar transformations, yet scientists know relatively little about the genes involved. Researchers led by Michael Montague, a postdoc at the Washington University School of Medicine in St. Louis, have now pinpointed some of them. The scientists started with the genome of a domestic cat—a female Abyssinian—that had been published in draft form in 2007, then filled in missing sequences and identified genes. They compared the resulting genome with those of cows, tigers, dogs, and humans. © 2014 American Association for the Advancement of Science.

Keyword: Genes & Behavior; Aggression
Link ID: 20298 - Posted: 11.11.2014

By Paula Span A few days after I wrote about conditions that can mimic dementia, reader Sue Murray emailed me from Westchester County. Her subject line: “Have you heard of Charles Bonnet Syndrome?” I hadn’t, and until about six months ago, neither had Ms. Murray. Her mother Elizabeth, who is 91, has glaucoma and macular degeneration, and has been gradually losing her vision, Ms. Murray explained. So at first, her family was excited when Elizabeth seemed to be seeing things more clearly. Maybe, they thought, her vision was returning. But the things she was seeing — patterns and colors, strangers, a green man — weren’t there. She insisted that “there were people in the cellar, people on the porch, people in the house,” Ms. Murray said. “She’d point and say, ‘Don’t you see them?’ And she’d get mad when we didn’t.” Elizabeth and her husband Victor, 95, live in Connecticut, in a house they bought 50 years ago. For a while, the Green Man, as Elizabeth began calling him, seemed to have moved in, too. “She’d start hiding things in the closet so the Green Man wouldn’t take them,” Ms. Murray said. “There wasn’t any real fear; it was just, ‘Look at that!’” Elizabeth’s ophthalmologist promptly supplied the name for this condition: Charles Bonnet Syndrome, named for a Swiss philosopher who described such visual hallucinations in the 18th century. “We were relieved,” said Ms. Murray. What they feared, of course, was mental illness or dementia. “To have an eye doctor say, ‘I’m familiar with this,’ it’s still jarring but it’s not so terrible.” Bonnet Syndrome (pronounced Boh-NAY) isn’t terribly rare, it turns out. Oliver Sacks described several cases in his 2012 book, “Hallucinations.” Dr. Abdhish Bhavsar, a clinical spokesperson for the American Academy of Ophthalmology and a retina specialist in Minneapolis, estimates that he has probably seen about 200 patients with the syndrome over 17 years of practice. © 2014 The New York Times Company

Keyword: Vision; Aggression
Link ID: 20297 - Posted: 11.10.2014

By Meeri Kim Patients suffering from pagophagia compulsively crave and chomp on ice, even scraping buildup off freezer walls for a fix. The disorder appears to be caused by an iron deficiency, and supplements of the mineral tend to ease the cravings. But what is it about ice that makes it so irresistible? A new study proposes that, like a strong cup of coffee, ice may give those with insufficient iron a much-needed mental boost. Fatigue is the most common symptom of iron-deficiency anemia, which occurs when the body can’t produce enough oxygen-carrying hemoglobin because of low iron. “I had a friend who was suffering from iron-deficiency anemia who was just crunching through massive amounts of ice a day,” said study author Melissa Hunt, a clinical psychologist at the University of Pennsylvania. “She said: ‘It’s like a cup of coffee. I don’t feel awake until I have a cup of ice in my hand.’ ” Hunt and her colleagues had both anemic and healthy subjects complete a standardized, 22-minute attention test commonly used to diagnose attention deficit hyperactivity disorder. Just before the test, participants were given either a cup of ice or lukewarm water to consume. Iron-deficient subjects who had sipped on water performed far more slugglishly on the test than controls, as expected. But those who ate ice beforehand did just as well as their healthy counterparts. For healthy subjects, having a cup of ice instead of water appeared to make no difference in test performance. “It’s not like craving a dessert. It’s more like needing a cup of coffee or that cigarette,” Hunt said.

Keyword: Attention
Link ID: 20296 - Posted: 11.10.2014

By James Gallagher Health editor, BBC News website The brain has specialist neurons for each of the five taste categories - salty, bitter, sour, sweet and umami - US scientists have discovered. The study, published in the journal Nature, should settle years of debate on how the brain perceives taste. The Columbia University team showed the separate taste sensors on the tongue had a matching partner in the brain. The scientists hope the findings could be used to help reverse the loss of taste sensation in the elderly. It is a myth that you taste sweet only on the tip of the tongue. Each of the roughly 8,000 taste buds scattered over the tongue is capable of sensing the full suite of tastes. But specialised cells within the taste bud are tuned to either salty, bitter, sour, sweet or umami tastes. When they detect the signal, a message is sent to the brain. Although how the brain deals with the information has been up for discussion. A team at Columbia University engineered mice so that their taste neurons would fluoresce when they were activated. They then trained their endoscopes on the neurons deep at their base of the brain. The animals were fed chemicals to trigger either a salty, bitter, sour, sweet or umami response on the tongue and the researchers monitored the change in the brain. They found a "hard wired" connection between tongue and brain. Prof Charles Zuker told the BBC News website: "The cells were beautifully tuned to discrete individual taste qualities, so you have a very nice match between the nature of the cells in your tongue and the quality they represent [in the brain]." It scotches the alternative idea that brain cells respond to multiple tastes. BBC © 2014

Keyword: Chemical Senses (Smell & Taste)
Link ID: 20295 - Posted: 11.10.2014

By Katy Waldman How much control do you have over how much control you think you have? The researchers Michael R. Ent and Roy F. Baumeister have been studying what makes a person more or less likely to believe in free will. Is it a deep connection to the philosophy of David Hume? An abiding faith in divine omnipotence? Try a really, really full bladder. In an online survey, 81 adults ages 18 to 70 reported the extent to which they felt hungry, tired, desirous of sex, and desirous of a toilet. They then rated the extent to which they considered themselves in command of their destinies. People experiencing intense physical needs were less likely to say they believed in free will. People who were not inexplicably taking an online survey while desperately holding in their pee (or starving, or wanting sex, or trying to stay awake) mostly claimed that the universe had handed them the keys to their lives. Also, people who brought their laptops with them into the bathroom to fill out the survey reported that they were God. (I kid on that last part.) Ent and Baumeister also used a survey to take the free will temperature of 23 people with panic disorder, 16 people with epilepsy, and 35 healthy controls. Those suffering from the two conditions—both of which can unpredictably plunge the mind into chaos—tended to put less stock in the notion of mental autonomy. There was a third experiment, too. I said earlier that people not taking an online survey while jonesing for various creature comforts mostly claimed that they wore the metaphysical pants. However, despite robust results for horniness, fatigue, and needing-to-go-ness, Ent and Baumeister didn’t initially see much correlation between people’s philosophical visions and their hunger levels. So they re-administered the survey to 112 new volunteers, some of whom were dieting and some of whom were not. © 2014 The Slate Group LLC.

Keyword: Consciousness
Link ID: 20294 - Posted: 11.10.2014

By Dr. Catherine A. Madison “Now why did I walk into this room? Oh, yes, looking for my …” This scenario, familiar to many, is most often a sign of normal aging — or of having too much on our minds. But when these events seem to be happening frequently, is it a more serious problem, such as Alzheimer’s disease or another dementia? Even more importantly, are there good health habits that can help lower the risk of these neurodegenerative conditions? Research continues to demonstrate that healthy lifestyles lower one’s risk of developing cognitive decline later in life. Wise food choices and lots of exercise are a good base, along with learning new material and keeping socially connected. But another key element to brain health is good sleep. We may take sleep for granted, but research suggests this is not a passive process. There is a growing consensus that sleep is linked to learning, memory, nerve cell remodeling and repair. Evidence also suggests lack of sleep can contribute to mood and immune disorders, as well as to a decline in overall health. Most of us have read the dos and don’ts of good sleep hygiene: avoid napping, don’t drink alcohol or caffeine close to bedtime, avoid late-evening exercise and sleep in a room that is quiet, dark and cool. We’ve also been told about sleep cycles, in which we typically progress from light sleep early in the night to slow wave sleep with rapid eye movement, or REM, later on. We need a balance of sleep cycles for optimal health.

Keyword: Sleep; Aggression
Link ID: 20293 - Posted: 11.10.2014

Stem cells can be used to heal the damage in the brain caused by Parkinson's disease, according to scientists in Sweden. They said their study on rats heralded a "huge breakthrough" towards developing effective treatments. There is no cure for the disease, but medication and brain stimulation can alleviate symptoms. Parkinson's UK said there were many questions still to be answered before human trials could proceed. The disease is caused by the loss of nerve cells in the brain that produce the chemical dopamine ,which helps to control mood and movement. To simulate Parkinson's, Lund University researchers killed dopamine-producing neurons on one side of the rats' brains. They then converted human embryonic stem cells into neurons that produced dopamine. Parkinson's Disease Parkinson's is one of the commonest neurodegenerative diseases These were injected into the rats' brains, and the researchers found evidence that the damage was reversed. There have been no human clinical trials of stem-cell-derived neurons, but the researchers said they could be ready for testing by 2017. Malin Parmar, associate professor of developmental and regenerative neurobiology, said: "It's a huge breakthrough in the field [and] a stepping stone towards clinical trials." A similar method has been tried in a limited number of patients. It involved taking brain tissue from multiple aborted foetuses to heal the brain. Clinical trials were abandoned after mixed results, but about a third of the patients had foetal brain cells that functioned for 25 years. BBC © 2014

Keyword: Parkinsons
Link ID: 20292 - Posted: 11.08.2014

Carl Zimmer Milk is not just food. The more closely scientists examine it, the more complexity they find. Along with nutrients like protein and calcium, milk contains immune factors that protect infants from disease. It hosts a menagerie of microbes, too, some of which may colonize the guts of babies and help them digest food. Milk even contains a special sugar that can fertilize that microbial garden. Now, it turns out, milk also contains messages. A new study of monkeys, published in the journal Behavioral Ecology, demonstrates that a hormone present in milk, cortisol, can have profound effects on how babies develop. Infant monkeys rely on cortisol to detect the condition of their mothers, the authors suggest, then adjust their growth and even shift their temperaments. Jeffrey French, a neuroendocrinologist at the University of Nebraska at Omaha who was not involved in the study, praised its “remarkable sophistication” and said that it helped to change how we think about breast milk. “Milk serves almost like a pheromone, a chemical signal sent from one individual to another,” he said. Katie Hinde, a behavioral biologist at Harvard and lead author on the new study, and her colleagues studied 108 rhesus macaque mothers nursing infants at the California National Primate Research Center. The researchers collected samples of milk, measuring how much energy each provided and the cortisol it contained. Dr. Hinde and her colleagues also measured how much weight each nursing monkey gained and tracked its behavior. Cortisol serves many functions in mammals, but it is best known as a stress hormone. When cortisol courses through our bodies, it prepares us to handle alarming or fearful situations, increasing the brain’s consumption of glucose and suppressing the digestive system. © 2014 The New York Times Company

Keyword: Sexual Behavior; Aggression
Link ID: 20291 - Posted: 11.08.2014

By Greg Miller This robot causes people to experience the illusory sensation of someone standing behind them. © Alain Herzog/EPFL People who’ve stared death in the face and lived to tell about it—mountain climbers who’ve made a harrowing descent, say, or survivors of the World Trade Center attacks—sometimes report that just when their situation seemed impossible, a ghostly presence appeared. People with schizophrenia and certain types of neurological damage sometimes report similar experiences, which scientists call, aptly, “feeling of presence.” Now a team of neuroscientists says it has identified a set of brain regions that seems to be involved in generating this illusion. Better yet, they’ve built a robot that can cause ordinary people to experience it in the lab. The team was led by Olaf Blanke, a neurologist and neuroscientist at the Swiss Federal Institute of Technology in Lausanne. Blanke has a long-standing interest in creepy illusions of bodily perception. Studying these bizarre phenomena, he says, could point to clues about the biology of mental illness and the mechanisms of human consciousness. In 2006, for example, Blanke and colleagues published a paper in Nature that had one of the best titles you’ll ever see in a scientific journal: “Induction of an illusory shadow person.” In that study, they stimulated the brain of a young woman who was awaiting brain surgery for severe epilepsy. Surgeons had implanted electrodes on the surface of her brain to monitor her seizures, and when the researchers passed a mild current through the electrodes, stimulating a small region at the intersection of the temporal and parietal lobes of her brain, she experienced what she described as a shadowy presence lurking nearby, mimicking her own posture. Colored areas indicate regions of overlap in the lesions of neurological patients who experienced feeling of presence illusions. © 2014 Condé Nast.

Keyword: Attention; Aggression
Link ID: 20290 - Posted: 11.08.2014

By Tracy Jarrett Autism advocates on Friday applauded Jerry Seinfeld's disclosure that he may be autistic, while warning against making him the poster boy for a disorder that is no laughing matter. “I think, on a very drawn-out scale, I think I’m on the spectrum,” Seinfeld told NBC Nightly News’ Brian Williams. "Basic social engagement is really a struggle. I'm very literal, when people talk to me and they use expressions, sometimes I don't know what they're saying," he said. "But I don't see it as dysfunctional, I just think of it as an alternate mindset." Seinfeld's revelation sends a positive message that the autism community is much larger and more diverse than people often understand, Ari Ne’eman, president of the Autistic Advocacy Network, told NBC News. Ne’eman is living with autism and says that there is still a tremendous amount of stigma surrounding autism that hinders the opportunities available to those with the disorder. “Think about what this does for a closeted autistic person who goes into the workplace knowing that their co-workers have just seen somebody they know, respect, and have a positive opinion of, like Jerry Seinfeld, identify in this way — it’s a valuable and important step in building a greater tolerance for autism,” Ne’eman said. Liz Feld, president of Autism Speaks, agreed, pointing out that “there are many people on the autism spectrum who can relate to Jerry’s heartfelt comments about his own experiences.”

Keyword: Autism
Link ID: 20289 - Posted: 11.08.2014

by Penny Sarchet It's frustrating when your smartphone loses its signal in the middle of a call or when downloading a webpage. But for bats, a sudden loss of its sonar signal means missing an insect meal in mid-flight. Now there's evidence to suggest that bats are sneakily using sonar jamming techniques to make their fellow hunters miss their tasty targets. Like other bats, the Mexican free-tailed bat uses echolocation to pinpoint prey insects in the dark. But when many bats hunt in the same space, they can interfere with each other's echoes, making detection more difficult. Jamming happens when a sound disrupts a bat's ability to extract location information from the echoes returning from its prey, explains Aaron Corcoran of Johns Hopkins University in Baltimore, Maryland. Previous research has shown that Mexican free-tailed bats can get around this jamming by switching to higher pitches. Using different sound frequencies to map the hunting grounds around them allows many bats to hunt in the same space. In these studies, jamming of each other's signals was seemingly inadvertent – a simple consequence of two bats attempting to echolocate in close proximity. But Corcoran has found evidence of sneakier goings-on. Corcoran has found a second type of sonar jamming in these bats – intentional sabotage of a fellow bat. "In this study, the jamming is on purpose and the jamming signal has been designed by evolution to maximally disrupt the other bat's echolocation," he says. © Copyright Reed Business Information Ltd.

Keyword: Hearing
Link ID: 20288 - Posted: 11.08.2014

By Dwayne Godwin and Jorge Cham © 2014 Scientific American

Keyword: Consciousness; Aggression
Link ID: 20287 - Posted: 11.08.2014

Sara Reardon Delivering medications to the brain could become easier, thanks to molecules that can escort drugs through the notoriously impervious sheath that separates blood vessels from neurons. In a proof-of-concept study in monkeys, biologists used the system to reduce levels of the protein amyloid-β, which accumulates in the brain plaques associated with Alzheimer's disease1. The blood–brain barrier is a layer of cells lining the inner surface of the capillaries that feed the central nervous system. It is nature's way of protecting the delicate brain from infectious agents and toxic compounds, while letting nutrients and oxygen in and waste products out. Because the barrier strictly regulates the passage of larger molecules and often prevents drug molecules from entering the brain, it has long posed one of the most difficult challenges in developing treatments for brain disorders. Several approaches to bypassing the barrier are being tested, including nanoparticles that are small enough to pass through the barrier's cellular membranes and deliver their payload; catheters that carry a drug directly into the brain; and ultrasound pulses that push microbubbles through the barrier. But no approach has yet found broad therapeutic application. Neurobiologist Ryan Watts and his colleagues at the biotechnology company Genentech in South San Francisco have sought to break through the barrier by exploiting transferrin, a protein that sits on the surface of blood vessels and carries iron into the brain. The team created an antibody with two ends. One end binds loosely to transferrin and uses the protein to transport itself into the brain. And once the antibody is inside, its other end targets an enzyme called β-secretase 1 (BACE1), which produces amyloid-β. Crucially, the antibody binds more tightly to BACE1 than to transferrin, and this pulls it off the blood vessel and into the brain. It locks BACE1 shut and prevents it from making amyloid-β. © 2014 Nature Publishing Group,

Keyword: Alzheimers
Link ID: 20286 - Posted: 11.06.2014

|By Lindsey Konkel and Environmental Health News New York City children exposed in the womb to high levels of pollutants in vehicle exhaust had a five times higher risk of attention problems at age 9, according to research by Columbia University scientists published Wednesday. The study adds to earlier evidence that mothers' exposures to polycyclic aromatic hydrocarbons (PAHs), which are emitted by the burning of fossil fuels and other organic materials, are linked to children's behavioral problems associated with Attention Deficit Hyperactivity Disorder (ADHD). “Our research suggests that environmental factors may be contributing to attention problems in a significant way,” said Frederica Perera, an environmental health scientist at Columbia’s Mailman School of Public Health who was the study's lead author. About one in 10 U.S. kids is diagnosed with ADHD, according to the Centers for Disease Control and Prevention. Children with ADHD are at greater risk of poor academic performance, risky behaviors and lower earnings in adulthood, the researchers wrote. “Air pollution has been linked to adverse effects on attention span, behavior and cognitive functioning in research from around the globe. There is little question that air pollutants may pose a variety of potential health risks to children of all ages, possibly beginning in the womb,” said Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Steven & Alexandra Cohen Children’s Medical Center of New York. He did not participate in the new study. © 2014 Scientific American

Keyword: ADHD; Aggression
Link ID: 20285 - Posted: 11.06.2014