By Bill Andrews In a paper sure to please lazy stand-up comics and beleaguered husbands everywhere, scientists say that men do indeed have a hard time understanding women. Recent results show that men have a significantly harder time recognizing women’s emotions than they do men’s, and that men seem to use different parts of their brain when ascribing intentions and feelings to women versus men. Previous experiments had suggested that men are naturally wired to be more intuitive toward other men’s mental states and emotions. Eager to figure out why and how this could be, the researchers studied the brains of 22 male participants as they received a version of a well-known empathy test called the “Reading the Mind in the Eyes Test.” (You can take a version of the test online here.) As the name suggests, the test consists of snapshots of pairs of eyes. Pairs of eyes were shown in succession to each participant, who had to determine either the gender or the emotional state of the person pictured. This all took place within an MRI machine, allowing the researchers to see which parts of the brain were active while participants made their determinations. Participants were about equally good at guessing the gender of male and female eyes, but the men did significantly worse at recognizing the emotions of the female eyes. They correctly interpreted about 87 percent of men’s eyes but only about 76 percent of women’s eyes. Participants also took longer to judge women’s emotions—about 40 milliseconds longer on average. Thus, in effect, men can “read” other men’s eyes faster and better, the researchers report in PLOS ONE.

Keyword: Emotions; Sexual Behavior
Link ID: 18028 - Posted: 04.13.2013

Sid Perkins The two-million-year-old remains of a novel hominin discovered in August 2008 are an odd blend of features seen both in early humans and in the australopithecines presumed to have preceded them. A battery of six studies1–6 published today in Science scrutinizes the fossils of Australopithecus sediba from head to heel and yields unprecedented insight into how the creature walked, chewed and moved. Together, the studies suggest that this hominin was close to the family tree of early humans — although it remains controversial whether it was one of our direct ancestors. “We see evolution in action across this skeleton,” says Lee Berger, a palaeoanthropologist at the University of the Witwatersrand in Johannesburg, South Africa. For instance, whereas the creature’s arms are ape-like, its hands and wrists are remarkably like those of humans. And although the hominin’s pelvis is shaped like a modern human's, its torso included a narrow upper rib cage like those found in apes. One of the six studies focused on Au. sediba’s teeth1, comparing 22 different aspects across hundreds of teeth from several other species of australopithecines and thousands of early human teeth. Tooth similarities among the species are more likely to signify common ancestry than independent evolution towards a beneficial design, says Debbie Guatelli-Steinberg, an anthropologist at Ohio State University in Columbus. That's because most of the characteristics the team chose to study, such as the subtle curvature of a portion of the tooth’s surface, are not likely to be evolutionarily useful. © 2013 Nature Publishing Group

Keyword: Evolution
Link ID: 18027 - Posted: 04.13.2013

by Simon Makin The first drug specifically designed to improve cognitive impairment in Down's syndrome is being tested in humans. David Nutt, former drug policy adviser to the UK government, told delegates at the Festival of Neuroscience in London yesterday that he is collaborating with pharmaceutical company Roche in trials of a substance it developed, called RG1662. RG1662 reverses the effects of a chemical messenger in the brain called GABA – a neurotransmitter that inhibits brain activity. The drug acts on a specific type of brain receptor found mostly in the hippocampus, a part of the brain involved in memory. It is thought that it will reduce excessive inhibition in the hippocampus, thought to underlie memory and learning problems commonly seen in people with Down's. The study is currently assessing safety and tolerability of the drug in 33 adults with Down's, but researchers will also measure motor skills, reaction time and memory, and compare the results with those of people taking a placebo. The aim is to find appropriate doses to use in a full clinical trial, which Nutt says should happen this year. Roche said in a statement that RG1662 may help people with Down's as it has "a unique pharmacology that enables the targeting of GABA over-activity mainly in brain systems important for cognition, learning and memory". © Copyright Reed Business Information Ltd

Keyword: Learning & Memory
Link ID: 18026 - Posted: 04.13.2013

Published by scicurious I love salt. It's just delicious. I wrote this post while noshing on deliciously salty popcorn, after a dinner which I put salt on. I crave salt so much that my parents used to joke about getting me a salt lick. And I'm not alone. Sodium is an incredibly important part of life, which means it's also an important part of what we eat. To make sure we get enough salt, animals have evolved salt-sensing systems, and low levels (below 100 mM of NaCl) of salt are very attractive. But there IS such a thing as too much salt. High levels of salt (>300 mM NaCl) are really aversive (from personal experience, I wonder if Carrabba's restaurant has concentrations of salt in their food over 300 mM). Most animals will quickly turn up their noses at a high salt concentration. You probably know that you have classes of receptors on your tongue for taste (though they are not clustered into areas of your mouth, like front for sweetness, as previously thought). You have sweet, umami (savory), bitter, sour, and salt. In most animals, sweet and umami are always attractive, while bitter and sour are nasty (except where we have overcome the aversion to enjoy things like coffee and beer). Salt, though, is the only one that goes two ways, with low levels being attractive and high levels being aversive. Now we know how low salt works. The salt receptors that are currently known are good for detecting low salt. But high salt, that's more difficult. First of all, our aversion to high salt concentrations is not very selective. While low salt detection is limited to good old NaCl, high salt detection is non-specific, working for many salts including NaCl, but others as well (like KCl). Neurotic Physiology Copyright © 2013

Keyword: Chemical Senses (Smell & Taste)
Link ID: 18025 - Posted: 04.13.2013

by Helen Shen A thermometer is great for measuring a fever, but when it comes to pain, doctors must rely on the age-old question, "How bad is it?" Scientists have long struggled to find physiological signs that can reliably tell "ouch" from "@#%!" and everything in between. Now, a brain scanning study suggests that painful heat excites a specific pattern of neural activity that could hold the key to better diagnosis and treatment of all kinds of pain in the future. Functional magnetic resonance imaging (fMRI) studies have shown that certain areas of the brain—including the anterior cingulate cortex, somatosensory cortex, and thalamus—activate when people experience pain. But those same regions also light up in response to other experiences, such as painful thoughts or social rejection. In recent years, scientists have looked for a particular pattern of activity across these areas that single out the experience of physical pain. "What we're evolving towards is trying to predict quantitatively from patterns of brain activity how much an individual is feeling," says Tor Wager, a neuroscientist at the University of Colorado, Boulder. In the new study, Wager's group performed fMRI brain scans on a total of 114 healthy participants while delivering different amounts of heat to the volunteers' arms with a computer-controlled hot plate. In an initial experiment, the scientists used data from 20 people to find a brain-wide pattern of excitation and inhibition—a neural "signature"—that changed reliably as people experienced varying degrees of heat, ranging from painless to scalding. In the remainder of the study, Wager and his colleagues were able use the signature derived from the first group to predict pain responses in a completely different set of subjects—a promising sign for one day using such a model on patients suffering from unknown conditions, he says. © 2010 American Association for the Advancement of Science.

Keyword: Pain & Touch; Brain imaging
Link ID: 18024 - Posted: 04.11.2013

by Elizabeth Norton A loving gaze helps firm up the bond between parent and child, building social skills that last a lifetime. But what happens when mom is blind? A new study shows that the children of sightless mothers develop healthy communication skills and can even outstrip the children of parents with normal vision. Eye contact is one of the most important aspects of communication, according to Atsushi Senju, a developmental cognitive neuroscientist at Birkbeck, University of London. Autistic people don't naturally make eye contact, however, and they can become anxious when urged to do so. Children for whom face-to-face contact is drastically reduced—babies severely neglected in orphanages or children who are born blind—are more likely to have traits of autism, such as the inability to form attachments, hyperactivity, and cognitive impairment. To determine whether eye contact is essential for developing normal communication skills, Senju and colleagues chose a less extreme example: babies whose primary caregivers (their mothers) were blind. These children had other forms of loving interaction, such as touching and talking. But the mothers were unable to follow the babies' gaze or teach the babies to follow theirs, which normally helps children learn the importance of the eyes in communication. Apparently, the children don't need the help. Senju and colleagues studied five babies born to blind mothers, checking the children's proficiency at 6 to 10 months, 12 to 15 months, and 24 to 47 months on several measures of age-appropriate communications skills. At the first two visits, babies watched videos in which a woman shifted her gaze or moved different parts of her face while corresponding changes in the baby's face were recorded. Babies also followed the gaze of a woman sitting at a table and looking at various objects. © 2010 American Association for the Advancement of Science

Keyword: Development of the Brain; Emotions
Link ID: 18023 - Posted: 04.11.2013

By Daisy Yuhas Less than two hundred years ago, schizophrenia emerged from a tangle of mental disorders known simply as madness. Yet its diagnosis remains shrouded in ambiguity. Only now is the Diagnostics and Statistical Manual of Mental Disorders, psychiatrists’ primary guidebook, shedding the outdated, nineteenth-century descriptions that have characterized schizophrenia to this day. "There is substantial dissatisfaction with schizophrenia treated as a disease entity, it's symptoms are like a fever—something is wrong but we don't know what," says William Carpenter, a psychiatrist at the University of Maryland and chair of the manual’s Psychotic Disorder Workgroup. Psychiatrists may discover that this disorder is not a single syndrome after all but a bundle of overlapping conditions. © 2013 Scientific American,

Keyword: Schizophrenia
Link ID: 18022 - Posted: 04.11.2013

by Caroline Williams When it comes to making decisions, it seems that the conscious mind is the last to know. We already had evidence that it is possible to detect brain activity associated with movement before someone is aware of making a decision to move. Work presented this week at the British Neuroscience Association (BNA) conference in London not only extends it to abstract decisions, but suggests that it might even be possible to pre-emptively reverse a decision before a person realises they've made it. In 2011, Gabriel Kreiman of Harvard University measured the activity of individual neurons in 12 people with epilepsy, using electrodes already implanted into their brain to help identify the source of their seizures. The volunteers took part in the "Libet" experiment, in which they press a button whenever they like and remember the position of a second hand on a clock at the moment of decision. Kreiman discovered that electrical activity in the supplementary motor area, involved in initiating movement, and in the anterior cingulate cortex, which controls attention and motivation, appeared up to 5 seconds before a volunteer was aware of deciding to press the button (Neuron, doi.org/btkcpz). This backed up earlier fMRI studies by John-Dylan Haynes of the Bernstein Center for Computational Neuroscience in Berlin, Germany, that had traced the origins of decisions to the prefrontal cortex a whopping 10 seconds before awareness (Nature Neuroscience, doi.org/cs3rzv). "It's always nice when two lines of research converge and to know that what we see with fMRI is actually there in the neurons," says Haynes. © Copyright Reed Business Information Ltd.

Keyword: Consciousness
Link ID: 18021 - Posted: 04.11.2013

by Ed Yong The brain has hit the big time. Barack Obama has just announced $100 million of funding for the BRAIN Intitiative—an ambitious attempt to apparently map the activity of every neuron in the brain. On the other side of the Atlantic, the Human Brain Project will try to simulate those neurons with a billion euros of funding from the European Commission. And news about neuroscience, from dream-decoding to mind-melding to memory-building, regularly dominates the headlines. But while the field’s star seems to be rising, a new study casts a disquieting shadow upon the reliability of its results. A team of scientists led by Marcus Munafo from the University of Bristol analysed a broad range of neuroscience studies and found them plagued by low statistical power. Statistical power refers to the odds that a study will find an effect—say, whether antipsychotic drugs affect schizophrenia symptoms, or whether impulsivity is linked to addiction—assuming those effects exist. Most scientists regard a power of 80 percent as adequate—that gives you a 4 in 5 chance of finding an effect if there’s one to be found. But the studies that Munafo’s team examined tended to be so small that they had an average (median) power of just 21 percent. At that level, if you ran the same experiment five times, you’d only find an effect on one of those. The other four tries would be wasted. But if studies are generally underpowered, there are more worrying connotations beyond missed opportunities. It means that when scientists do claim to have found effects—that is, if experiments seem to “work”—the results are less likely to be real. And it means that if the results are actually real, they’re probably bigger than they should be. As the team writes, this so-called “winner’s curse” means that “a ‘lucky’ scientist who makes the discovery in a small study is cursed by finding an inflated effect.”

Keyword: Brain imaging; Schizophrenia
Link ID: 18020 - Posted: 04.11.2013

By Suzy Gage When I started my PhD a few years ago, I thought that certain psychological findings were established fact. The next four years were an exercise in disillusionment. If the effects I was seeking to explore were so reliable, so established, why could I not detect them? There is growing interest in the need to improve reliability in science. Many drugs show promise at the design and pre-clinical phases, only to fail (at great expense) in clinical trials. Many of the most hyped scientific discoveries eventually cannot be replicated. Worryingly for science (but somewhat comforting for my self-esteem as a researcher) this may be because many of the conclusions drawn from published research findings are false. A major factor that influences the reliability of science is statistical power. We cannot measure everyone or everything, so we take samples and use statistical inference to determine the probability that the results we observe in our sample reflect some underlying scientific truth. Statistical power determines whether we accurately conclude if there is an effect or not. Statistical power is the ability of a study to detect an effect (eg higher rates of cancer in smokers) given that an effect actually exists (smoking actually is associated with increased risk of cancer). Power is related to the size of the study sample (the number of smokers and non-smokers we test) and the size of the real effect (the magnitude of the increased risk associated with smoking). Larger studies have more power and can detect smaller, more subtle effects. Small studies have lower power and can only detect larger effects reliably. © 2013 Guardian News and Media Limited

Keyword: Miscellaneous
Link ID: 18019 - Posted: 04.11.2013

by Sara Reardon The Brain Activity Map project launched recently by President Obama – and funded to the tune of $100 million in the US budget announcement earlier this month – highlights the need for research that focuses both on how individual neurons work and the ways that different regions of the brain work together as a unit. Looking at individual neurons requires slicing up brains into thin sections. However, this damages the axons – the arms that protrude from neurons to make connections with other cells – making it difficult to see exactly how brain cells link up. A few microscopic techniques can focus light deep into the intact brains of dead animals to study its structure without damaging the axons, but much of this light is scattered away by the fatty lipid membranes that surround individual cells, making the technique less than perfect. Now Kwanghun Chung, Karl Deisseroth and their team at Stanford University in California have developed a technique that provides a clearer picture. First, they remove the brain from a mouse and infuse it with a see-through gel that collects in the neurons' lipid membranes. As the gel solidifies, it takes the shape of the membranes and creates a matrix that holds the cells' proteins, DNA and RNA in place. Then the team adds a second chemical that dissolves the lipids, leaving a transparent brain made out of gel that retains the brain's proteins, DNA and RNA in their original positions. © Copyright Reed Business Information Ltd.

Keyword: Brain imaging
Link ID: 18018 - Posted: 04.11.2013

By JAMES GORMAN Scientists at Stanford University reported on Wednesday that they have made a whole mouse brain, and part of a human brain, transparent so that networks of neurons that receive and send information can be highlighted in stunning color and viewed in all their three-dimensional complexity without slicing up the organ. Even more important, experts say, is that unlike earlier methods for making the tissue of brains and other organs transparent, the new process, called Clarity by its inventors, preserves the biochemistry of the brain so well that researchers can test it over and over again with chemicals that highlight specific structures and provide clues to past activity. The researchers say this process may help uncover the physical underpinnings of devastating mental disorders like schizophrenia, autism, post-traumatic stress disorder and others. The work, reported on Wednesday in the journal Nature, is not part of the Obama administration’s recently announced initiative to probe the secrets of the brain, although the senior author on the paper, Dr. Karl Deisseroth at Stanford, was one of those involved in creating the initiative and is involved in planning its future. Dr. Thomas Insel, director of the National Institute of Mental Health, which provided some of the financing for the research, described the new work as helping to build an anatomical “foundation” for the Obama initiative, which is meant to look at activity in the brain. Dr. Insel added that the technique works in a human brain that has been in formalin, a preservative, for years, which means that long-saved human brains may be studied. “Frankly,” he said, “that is spectacular.” © 2013 The New York Times Company

Keyword: Brain imaging
Link ID: 18017 - Posted: 04.11.2013

A rat with some human genes could provide a better way to test Alzheimer's drugs. The genetically modified rat is the first rodent model to exhibit the full range of brain changes found in Alzheimer's, researchers in The Journal of Neuroscience. "It's a big step forward" for drug development, says , a program director at the National Institute of Neurological Disorders and Stroke, or NINDS, which helped fund the work. "The closer the model is to the human condition in representing the disease, the more likely the drug will behave and cure the way it would in humans." In recent years, drug companies have developed several Alzheimer's drugs that seemed to work in animals, but with the disease. A lack of good animal models for Alzheimer's may be one reason for those failures, researchers say. For the past couple of decades, Alzheimer's researchers have relied primarily on mice that carry human gene mutations that cause people to get the disease in their 40s or 50s. Like people, these mice develop so-called amyloid plaques in their brains. But that's where the similarity ends. In people with Alzheimer's, after plaques appear, huge numbers of brain cells die. That's never happened in mice, despite lots of genetic tinkering, Corriveau says. So researchers began to consider a different rodent model: the rat. "Rats are 4 [million] to 5 million years closer evolutionarily to humans," Corriveau says, which means their brains are more like ours. ©2013 NPR

Keyword: Alzheimers; Genes & Behavior
Link ID: 18016 - Posted: 04.11.2013

By GRETCHEN REYNOLDS Two new experiments, one involving people and the other animals, suggest that regular exercise can substantially improve memory, although different types of exercise seem to affect the brain quite differently. The news may offer consolation for the growing numbers of us who are entering age groups most at risk for cognitive decline. It was back in the 1990s that scientists at the Salk Institute for Biological Studies in La Jolla, Calif., first discovered that exercise bulks up the brain. In groundbreaking experiments, they showed that mice given access to running wheels produced far more cells in an area of the brain controlling memory creation than animals that didn’t run. The exercised animals then performed better on memory tests than their sedentary labmates. Since then, scientists have been working to understand precisely how, at a molecular level, exercise improves memory, as well as whether all types of exercise, including weight training, are beneficial. The new studies provide some additional and inspiring clarity on those issues, as well as, incidentally, on how you can get lab rats to weight train. For the human study, published in The Journal of Aging Research, scientists at the University of British Columbia recruited dozens of women ages 70 to 80 who had been found to have mild cognitive impairment, a condition that makes a person’s memory and thinking more muddled than would be expected at a given age. Mild cognitive impairment is also a recognized risk factor for increasing dementia. Seniors with the condition develop Alzheimer’s disease at much higher rates than those of the same age with sharper memories. Copyright 2013 The New York Times Company

Keyword: Learning & Memory
Link ID: 18015 - Posted: 04.10.2013

by Tanya Lewis, The lip-smacking vocalizations gelada monkeys make are surprisingly similar to human speech, a new study finds. Many nonhuman primates demonstrate lip-smacking behavior, but geladas are the only ones known to make undulating sounds, known as "wobbles," at the same time. (The wobbling sounds a little like a human hum would sound if the volume were being turned on and off rapidly.) The findings show that lip-smacking could have been an important step in the evolution of human speech, researchers say. "Our finding provides support for the lip-smacking origins of speech because it shows that this evolutionary pathway is at least plausible," Thore Bergman of the University of Michigan in Ann Arbor and author of the study published today (April 8) in the journal Current Biology,said in a statement. "It demonstrates that nonhuman primates can vocalize while lip-smacking to produce speechlike sounds." NEWS: Lip Smacks of Monkeys Prelude to Speech? Lip-smacking -- rapidly opening and closing the mouth and lips -- shares some of the features of human speech, such as rapid fluctuations in pitch and volume. (See Video of Gelada Lip-Smacking) Bergman first noticed the similarity while studying geladas in the remote mountains of Ethiopia. He would often hear vocalizations that sounded like human voices, but the vocalizations were actually coming from the geladas, he said. He had never come across other primates who made these sounds. But then he read a study on macaques from 2012 revealing how facial movements during lip-smacking were very speech-like, hinting that lip-smacking might be an initial step toward human speech. © 2013 Discovery Communications, LLC.

Keyword: Language; Evolution
Link ID: 18014 - Posted: 04.10.2013

Ed Yong Every autumn, millions of monarch butterflies (Danaus plexippus) converge on a small cluster of Mexican mountains to spend the winter. They have journeyed for up to 4,000 kilometres from breeding grounds across eastern North America. And according to a study, they accomplish this prodigious migration without ever knowing where they are relative to their destination. The monarchs can use the position of the Sun as a compass, but when Henrik Mouritsen, a biologist at the University of Oldenburg in Germany, displaced them by 2,500 kilometres, he found that they did not correct their heading. “People seemed to assume that they had some kind of a map that allowed them to narrow in on a site a few kilometres across after travelling several thousands of kilometres,” he says. Now, “it is clear that they don’t”. His results are published in the Proceedings of the National Academy of Sciences1. For more than five decades, scientists have teamed up with amateurs to tag and monitor free-flying monarchs, creating a database of their migrations. When Mouritsen analysed these records, he realized that the monarchs tend to spread out over the course of their migration. Their distribution was a good fit with the predictions of a mathematical model that assumed that the monarchs were flying with just a compass, rather than a compass and a map. Mouritsen also captured 76 southwesterly flying monarchs from fields near Guelph in Ontario, Canada, and transported them 2,500 kilometres to the west, to Calgary in the Canadian province of Alberta. He placed the butterflies in a “flight simulator” — a plastic cylinder that kept them from seeing any landmarks except the sky — and tethered them to a rod that let them point in any direction without actually flying away. © 2013 Nature Publishing Group

Keyword: Animal Migration
Link ID: 18013 - Posted: 04.10.2013

By PAULA SPAN The long list of roles Margaret Thatcher played during her 87 years — potent politician, free-market evangelist, labor antagonist, dominant global leader — includes the one she never publicly discussed: person with dementia. The stroke that killed her on Monday was not her first. Mrs. Thatcher suffered several small strokes more than a decade earlier, canceled all her speaking engagements in 2003 and largely withdrew from public life. Even before the strokes, her daughter, Carol, wrote in a 2008 memoir, she was losing cognitive ground, repeating questions and showing other signs of confusion. Heartbreakingly, she often forgot that her beloved husband, Denis, had died of cancer in 2003. “I had to keep giving her the bad news over and over again,” her daughter wrote. “Every time it finally sank in that she had lost her husband of more than 50 years, she’d look at me sadly and say, ‘Oh’, as I struggled to compose myself. ‘Were we all there?’ she’d ask softly.” At the time, members of her mother’s political circle and other British commentators denounced Carol Thatcher for invading her mother’s privacy and, supposedly, diminishing her dignity. The criticism arose again in some quarters last year, when Meryl Streep won an Oscar for her portrayal of Mrs. Thatcher’s dementia in “The Iron Lady.” © 2013 The New York Times Company

Keyword: Alzheimers
Link ID: 18012 - Posted: 04.10.2013

By Janice Lynch Schuster, My grandmother, who is 92, recently reported that she’d seen three giraffes in her Midwest back yard. She is otherwise sharp (and also kind and funny), but the giraffe episode was further evidence of the mild cognitive impairment that has been slowly creeping into her life. The question for my family has become: How should we respond? One of my sisters tried humor. (“Grandmom, I didn’t know you drank in the middle of the day!”) My father suggested that they were deer (to which she replied, “I’m 92 years old, and I know a giraffe when I see one.”) I tried to learn more about what, exactly, the giraffes were doing out there. (She didn’t seem to know, saying only that “the light shimmered.”) Communicating with a family member who has cognitive impairment can be frustrating and disheartening, even downright depressing for patient and caregiver alike. And it’s a problem faced by a growing number of Americans. According to a report published last week, about 4.1 million Americans have dementia. Alzheimer’s, one of the many forms of dementia, is the most expensive disease in the United States, costing $157 billion to $215 billion a year — more than heart disease and cancer, according to the study, which was sponsored by the National Institute on Aging. As baby boomers reach old age, these numbers are expected to increase dramatically. A number of techniques can not only reduce the frustration but also create new ways of connecting. Among the most effective and popular among experts is the “validation method,” a practice pioneered by geriatric social worker and researcher Naomi Feil in the 1980s. © 1996-2013 The Washington Post

Keyword: Alzheimers; Language
Link ID: 18011 - Posted: 04.10.2013

by Dr. Tyeese Gaines African-Americans with a particular gene are twice as likely to develop Alzheimer’s disease in old age as those without it, says a new study published in the Journal of the American Medical Association. This finding is a result of the largest database search for Alzheimer’s genes among African-Americans. “Until now, data on the genetics of Alzheimer’s in this patient population have been extremely limited,” said Dr. Richard Mayeux, chair of neurology at Columbia University Medical Center and senior author of the study. Alzheimer’s disease is the most common cause of dementia — a brain disease that affects memory, personality and the ability to reason. At age 65, only one percent of people have Alzheimer’s, yet over 80 years of age, it increases to 30 percent. A gene called APOE is associated with one in every five cases of Alzheimer’s – known to be a major genetic risk factor for whites and blacks. Yet, in this new research, Mayeux and his team identified an additional gene variant linked to a doubled risk in African-Americans alone, called ABCA7. “ABCA7 is the first major gene implicated in late-onset Alzheimer’s among African-Americans,” said Dr. Christine Reitz, assistant professor of neurology and lead author of the study. To reach this conclusion, researchers examined samples from nearly 6,000 African-American men and women collected between 1989 and 2011 – 2,000 had a diagnosis of probable Alzheimer’s disease and the other 4,000 had no cognitive difficulty. “Although this is a very significant finding, it does not change much for the everyday African-American male or female,” says Rick Kittles, PhD, a human genetics expert who has traced the ancestry of more than 100,000 African-Americans. “There is still much work to do [to] determine how exactly this gene plays a role in Alzheimer’s disease.” ©2013 NBCUniversal

Keyword: Alzheimers; Genes & Behavior
Link ID: 18010 - Posted: 04.10.2013

By Tara Haelle New evidence is confirming that the environment kids live in has a greater impact than factors such as genetics, insufficient physical activity or other elements in efforts to control child obesity. Three new studies, published in the April 8 Pediatrics, land on the import of the 'nurture' side of the equation and focus on specific circumstances in children's or teen's lives that potentially contribute to unhealthy bulk. In three decades child and adolescent obesity has tripled in the U.S., and estimates from 2010 classify more than a third of children and teens as overweight or obese. Obesity puts these kids at higher risk for type 2 diabetes, cardiovascular disease, sleep apnea, and bone or joint problems. The variables responsible are thought to range from too little exercise to too many soft drinks. Now it seems that blaming Pepsi or too little PE might neglect the bigger picture. "We are raising our children in a world that is vastly different than it was 40 or 50 years ago," says Yoni Freedhoff, an obesity doctor and assistant professor of medicine at the University of Ottawa. "Childhood obesity is a disease of the environment. It's a natural consequence of normal kids with normal genes being raised in unhealthy, abnormal environments." The environmental factors in these studies range from the seemingly minor, such as kids' plate sizes, to bigger challenges, such as school schedules that may keep teens from getting sufficient sleep. But they are part of an even longer list: the ubiquity of fast food, changes in technology, fewer home-cooked meals, more food advertising, an explosion of low-cost processed foods and increasing sugary drink serving sizes (pdf) as well as easy access to unhealthy snacks in vending machines, at sports games and in nearly every setting children inhabit—these are just a handful of environmental factors research has linked to increasing obesity, and researchers are starting to pick apart which among them play bigger or lesser roles in making kids supersized. © 2013 Scientific American

Keyword: Obesity; Genes & Behavior
Link ID: 18009 - Posted: 04.10.2013