By GRETCHEN REYNOLDS If you are aiming to lose weight by revving up your exercise routine, it may be wise to think of your workouts not as exercise, but as playtime. An unconventional new study suggests that people’s attitudes toward physical activity can influence what they eat afterward and, ultimately, whether they drop pounds. For some time, scientists have been puzzled — and exercisers frustrated — by the general ineffectiveness of exercise as a weight-loss strategy. According to multiple studies and anecdotes, most people who start exercising do not lose as much weight as would be expected, given their increased energy expenditure. Some people add pounds despite burning hundreds of calories during workouts. Past studies of this phenomenon have found that exercise can increase the body’s production of appetite hormones, making some people feel ravenous after even a light workout and prone to consume more calories than they expended. But that finding, while intriguing, doesn’t fully explain the wide variability in people’s post-exercise eating habits. So, for the new study, published in the journal Marketing Letters, French and American researchers turned to psychology and the possible effect that calling exercise by any other name might have on people’s subsequent diets. In that pursuit, the researchers first recruited 56 healthy, adult women, the majority of them overweight. The women were given maps detailing the same one-mile outdoor course and told that they would spend the next half-hour walking there, with lunch to follow. Half of the women were told that their walk was meant to be exercise, and they were encouraged to view it as such, monitoring their exertion throughout. The other women were told that their 30-minute outing would be a walk purely for pleasure; they would be listening to music through headphones and rating the sound quality, but mostly the researchers wanted them to enjoy themselves. When the women returned from walking, the researchers asked each to estimate her mileage, mood and calorie expenditure. © 2014 The New York Times Company

Keyword: Obesity; Emotions
Link ID: 19691 - Posted: 06.04.2014

by Catherine de Lange Could your ideal diet be written in your genes? That's the promise of nutrigenomics, which looks for genetic differences in the way people's bodies process food so that diets can be tailored accordingly. The field had a rocky start after companies overhyped its potential, but with advances in genetic sequencing, and a slew of new studies, the concept is in for a reboot. Last week, Nicola Pirastu at the University of Trieste, Italy, and his colleagues told the European Society of Human Genetics meeting in Milan that diets tailored to genes that are related to metabolism can help people lose weight. The team used the results of a genetic test to design specific diets for 100 obese people that also provided them with 600 fewer calories than usual. A control group was placed on a 600-calorie deficit, untailored diet. After two years, both groups had lost weight, but those in the nutrigenetic group lost 33 per cent more. They also took only a year to lose as much weight as the group on the untailored diet lost in two years. If this is shown to work in bigger, randomised trials, it would be fantastic, says Ana Valdes, a genetic epidemiologist at the University of Nottingham, UK. Some preliminary information will soon be available from Europe's Food4Me project. It is a study of 1200 people across several countries who were given either standard nutrition advice, or a similarly genetically tailored diet. "It's testing whether we can get bigger changes in diet using a personalised approach, and part of that is using genetic information," says team member John Mathers, director of the Human Nutrition Research Centre at Newcastle University, UK. © Copyright Reed Business Information Ltd.

Keyword: Chemical Senses (Smell & Taste); Obesity
Link ID: 19690 - Posted: 06.04.2014

Joy Jernigan TODAY contributor Depression is a serious medical condition that affects millions of Americans — and nearly twice as many women as men. Symptoms can include persistent feelings of sadness or hopelessness and loss of interest in activities that were once pleasurable, according to the National Institute of Mental Health. Other symptoms include feelings of guilt or worthlessness, irritability, changes in appetite, increased fatigue, difficulty concentrating — even recurrent thoughts of suicide. About 12 million American women suffer from depression each year, women like Debi Lee. Although depression is treatable, most commonly with medications or counseling, many never seek help, often because they are too embarrassed or ashamed. "Depression is really a physical illness," said Dr. Andrew Leuchter, a psychiatrist at the Semel Institute for Neuroscience and Human Behavior at University of California, Los Angeles. It's a disorder that even can be seen in brain scans, with images clearly showing the difference between a normal functioning brain and the brain of someone suffering from depression. "When you show this image to a person who's struggling with depression and you show them that their brain looks different than the quote so-called healthy person, what's their reaction?" Shriver asked. "It's commonly one of relief," Leuchter said. Now, Dr. Leuchter says there's an innovative new treatment called synchronized transcranial magnetic stimulation, or sTMS, that may have the potential to provide relief. Dr. Leuchter, a consultant and stockholder in the company behind sTMS, says it syncs to each patient's brain, then stimulates it with low levels of magnetic energy, 30 minutes a day for several weeks.

Keyword: Depression
Link ID: 19689 - Posted: 06.04.2014

Ewen Callaway By controlling rats' brain cells they had genetically engineered to respond to light, researchers were able to create fearful memories of events that never happened — and then to erase those memories again. Neuroscientists can breathe a collective sigh of relief. Experiments have confirmed a long-standing theory for how memories are made and stored in the brain. Researchers have created and erased frightening associations in rats' brains using light, providing the most direct demonstration yet that the strengthening and weakening of connections between neurons is the basis for memory. “This is the best evidence so far available, period,” says Eric Kandel, a neuroscientist at Columbia University in New York. Kandel, who shared the 2000 Nobel Prize in Physiology or Medicine for his work unravelling the molecular basis of memory, was not involved in the latest study, which was published online in Nature1 on 1 June. In the 1960s and 1970s, researchers in Norway noticed a peculiar property of brain cells. Repeatedly delivering a burst of electricity to a neuron in an area of the brain known as the hippocampus seemed to boost the cell’s ability to talk to a neighbouring neuron. These communiqués occur across tiny gaps called synapses, which neurons can form with thousands of other nerve cells. The process was called long-term potentiation (LTP), and neuroscientists suspected that it was the physical basis of memory. The hippocampus, they realized, was important for forming long-term memories, and the long-lasting nature of LTP hinted that information might be stored in a neural circuit for later recall. © 2014 Nature Publishing Group,

Keyword: Learning & Memory; Emotions
Link ID: 19688 - Posted: 06.03.2014

Ian Sample, science correspondent Research on children in Denmark has found that boys with autism were more likely to have been exposed to higher levels of hormones in their mother's wombs than those who developed normally. Boys diagnosed with autism and related disorders had, on average, raised levels of testosterone, cortisol and other hormones in the womb, according to analyses of amniotic fluid that was stored after their mothers had medical tests during pregnancy. The findings add to a growing body of evidence that the biological foundations of autism are laid down well before birth and involve factors that go beyond the child's genetic make-up. The results may help scientists to unravel some of the underlying causes of autism and explain why boys are four to five times more likely to be diagnosed with the condition, which affects around one percent of the population. Amniotic fluid surrounds babies in the womb and contains hormones and other substances that they have passed through their urine. The liquid is collected for testing when some women have an amniocentesis around four months into their pregnancy. Scientists in Cambridge and Copenhagen drew on Danish medical records and biobank material to find amniotic fluid samples from 128 boys who were later diagnosed with autism. Compared to a control group, the boys with autism and related conditions had higher levels of four "sex steroid" hormones that form a biological production line in the body that starts with progesterone and ends with testosterone. "In the womb, boys produce about twice as much testosterone as girls, but compared with typical boys, the autism group has even higher levels. It's a significant difference and may have a large effect on brain development," said Simon Baron-Cohen, director of the Autism Research Centre at Cambridge University. © 2014 Guardian News and Media Limited

Keyword: Autism; Hormones & Behavior
Link ID: 19687 - Posted: 06.03.2014

By MARK OPPENHEIMER When our young daughters first decided to play on top of our Honda minivan, parked in our driveway, my wife was worried. But to me, it seemed no less safe than chasing a ball that frequently ended up in the street. And they loved the height, the novelty, the danger. So I let them stay. They never fell. And with the summer weather here, playing on the car is once again keeping them occupied for hours. Now that I have read Paul Raeburn’s “Do Fathers Matter?,” I know that my comfort with more dangerous play — my willingness to let my daughters stand on top of a minivan — is a typically paternal trait. Dads roughhouse with children more, too. They also gain weight when their wives are pregnant and have an outsize effect on their children’s vocabulary. The presence of dads can delay daughters’ puberty. But older dads have more children with dwarfism and with Marfan syndrome. In Mr. Raeburn’s book, there is plenty of good news for dads, and plenty of bad. A zippy tour through the latest research on fathers’ distinctive, or predominant, contributions to their children’s lives, “Do Fathers Matter?” is filled with provocative studies of human dads — not to mention a lot of curious animal experiments. (You’ll learn about blackbirds’ vasectomies.) But above all, Mr. Raeburn shows how little we know about the role of fathers, and how preliminary his book is. Its end is really a beginning, a prospectus for further research. Mr. Raeburn writes that “as recently as a generation ago, in the 1970s, most psychologists” believed that “with regard to infants, especially, fathers were thought to have little or no role to play.” When it came to toddlers and older children, too, the great parenting theories of the 20th century placed fathers in the background. Freud famously exalted, or damned, the mother for her influence. John Bowlby’s attachment theory, which he developed beginning in the 1940s, focused on the mother or “mother-figure.” © 2014 The New York Times Company

Keyword: Sexual Behavior
Link ID: 19686 - Posted: 06.03.2014

|By Christie Nicholson Conventional wisdom once had it that each brain region is responsible for a specific task. And so we have the motor cortex for handling movements, and the visual cortex, for processing sight. And scientists thought that such regions remained fixed for those tasks beyond the age of three. But within the past decade researchers have realized that some brain regions can pinch hit for other regions, for example, after a damaging stroke. And now new research finds that the visual cortex is constantly doing double duty—it has a role in processing not just sight, but sound. When we hear [siren sound], we see a siren. In the study, scientists scanned the brains of blindfolded participants as the subjects listened to three sounds: [audio of birds, audio of traffic, audio of a talking crowd.] And the scientists could tell what specific sounds the subjects were hearing just by analyzing the brain activity in the visual cortex. [Petra Vetter, Fraser W. Smith and Lars Muckli, Decoding Sound and Imagery Content in Early Visual Cortex, in Current Biology] The next step is to determine why the visual cortex is horning in on the audio action. The researchers think the additional role conferred an evolutionary advantage: having a visual system primed by sound to see the source of that sound could have given humans an extra step in the race for survival. © 2014 Scientific American

Keyword: Vision; Hearing
Link ID: 19685 - Posted: 06.03.2014

Jessica Morrison Bees, like birds and butterflies, use the Sun as a compass for navigation, whereas mammals typically find their way by remembering familiar landmarks on a continuous mental map. However, the latest research suggests that bees also use this type of map, despite their much smaller brain size. The work adds a new dimension to complex bee-navigation abilities that have long captivated researchers. “The surprise comes for many people that such a tiny little brain is able to form such a rich memory described as a cognitive map,” says co-author Randolf Menzel, a neurobiologist at the Free University of Berlin. The research by Menzel and his team, published today in the Proceedings of the National Academy of Sciences1, demonstrates that bees can find their way back to their hives without relying solely on the Sun. Instead, they seem to use a 'cognitive map' that is made up of memorized landscape snapshots that direct them home. The cognitive map used by mammals is thought to originate in the brain’s hippocampus. Humans employ such maps on a daily basis; for example, even in a windowless office, many people can point towards their home, orienting themselves in space based on knowledge of their location relative to the outside world. “They can point to their home generally even though they can’t see it, even along a path through a wall that they haven’t travelled,” explains Fred Dyer, a behavioural biologist at Michigan State University in East Lansing, who was not involved in the research. The study authors argue that bees can do something similar, albeit on a much more rudimentary level. © 2014 Nature Publishing Group

Keyword: Animal Migration
Link ID: 19684 - Posted: 06.03.2014

By Lara Salahi A team of researchers at Massachusetts General Hospital have embarked on a new project to create an implantable device in the brain that would read and alter the emotions of someone with a mental illness. The team is working in collaboration with researchers at the University of California, San Francisco, on a new program funded by the Department of Defense’s Defense Advanced Research Projects Agency (DARPA). The researchers are working to create an implantable device that can sense abnormal activity in the brain using algorithms, and then deliver electrical impulses to certain parts of the brain that would suppress the abnormal signals. “Imagine if I have an addiction to alcohol and I have a craving,” Jose Carmena, a researcher at the University of California, Berkeley, who is involved in the project, told MIT Technology Review. “We could detect that feeling and then stimulate inside the brain to stop it from happening.” Mental illness and suicide rates among the US military have spiked over the past decade, the National Institute of Mental Healthreports. The current research is part of DARPA’s emerging neurotechnology therapy program which investigates new approaches to treat neuropsychological illnesses among military servicemembers and veterans. Their goal is to treat at least seven psychiatric conditions, including depression, post-traumatic stress disorder, addiction, and fibromyalgia.

Keyword: Emotions; Stress
Link ID: 19683 - Posted: 06.03.2014

Damage to certain parts of the brain can lead to a bizarre syndrome called hemispatial neglect, in which one loses awareness of one side of their body and the space around it. In extreme cases, a patient with hemispatial neglect might eat food from only one side of their plate, dress on only one side of their body, or shave or apply make-up to half of their face, apparently because they cannot pay attention to anything on that the other side. Research published last week now suggests that something like this happens to all of us when we drift off to sleep each night. The work could help researchers to understand the causes of hemispatial neglect, and why it affects one side far more often than the other. It also begins to reveal the profound changes in conscious experience that take place while we fall asleep, and the brain changes that accompany them. Hemispatial neglect is a debilitating condition that occurs often in people who suffer a stroke, where damage to the left hemisphere of the brain results in neglect of the right half of space, and vice versa. It can occur as a result of damage to certain parts of the frontal lobes, which are involved in alertness and attention, and the parietal lobes, which process information about the body and its surrounding space. In clinical tests, patients with hemispatial neglect are typically unaware of all kinds of stimuli in one half of space – they fail to acknowledge objects placed in the affected half of their visual field, for example and cannot state the location of touch sensations on the affected side of their body. Some may stop using the limbs on the affected side, or even deny that the limbs belong to them. Patients with neglect can usually see perfectly well, but information from the affected side just does not reach their conscious awareness. © 2014 Guardian News and Media Limited

Keyword: Sleep; Laterality
Link ID: 19682 - Posted: 06.03.2014

By DAAN HEERMA VAN VOSS I was 25 when I lost my memory. It happened on Jan. 16, 2012. I woke up, not knowing where I was. I was lying in bed, sure, but whose bed was it? There was no one in the room, no sound that I recognized: I was alone with my body. Of course, my relationship to my body was radically different than before. My body parts seemed to belong to someone else or, rather, to something else. The vague sense of identity that I possessed was confined to the knowledge of my name, but even that felt arbitrary — a collection of random letters, crumbling. No words can accurately describe the feeling of losing your memory, your life. Sammy Harkham Underlying the loss of facts is a deeper problem: the loss of logic and causality. A person can function, ask questions, only when he recognizes a fundamental link between circumstances and time, past and present. The links between something happening to you, leading you to do or say something, which leads to someone else responding. No act is without an act leading up to it, no word is without a word that came before. Without the sense of causality provided by memory, there is chaos. When I woke up, I had no grip on logic, and logic none on me. It was a profound not-knowing, and it was terrifying. I started hyperventilating. What struck me has a name: Transient Global Amnesia. T.G.A., as it’s referred to, is a neurological disorder. The name sounds definitive, but in fact, it’s just a fancy way of saying: We don’t know the cause, we know only what the symptoms are. Its most defining symptom is a near total disruption of short-term memory. In many cases, there is a temporary loss of long-term memory as well. But there is a bright side. T.G.A. lasts for approximately two to 20 hours, so it’s a one-day thing. At the time, though, I didn’t know this. Two names popped into my mind: Daniel and Sophie. I didn’t know where the names came from, or to whom they belonged. I stumbled across the room, opened a door, and discovered that I was alone in the apartment. (It was, in fact, my apartment.) I found an iPhone and, quite magically, I thought, knew how to work it. As it turns out, there was nothing magical about this: A characteristic of T.G.A. is that those afflicted with it can perform familiar tasks, even ones as difficult as driving a car. (But I wouldn’t recommend that.) Occurrence of T.G.A. is rare, with at most 10 cases per 100,000 people. It is most likely to happen when you’re between 40 and 80; the average age of a T.G.A. patient is 62 years old. But I have always been in the fast lane. © 2014 The New York Times Company

Keyword: Learning & Memory
Link ID: 19681 - Posted: 06.02.2014

By SANFORD E. DeVOE IN recent years we have seen plenty of studies of the impact of fast food on our bodies. But what about our psychological health? It stands to reason that fast food would have an effect on our mental state. From its production to its consumption, fast food both embodies and symbolizes speed and instant gratification. Moreover, through extensive franchising and large advertising budgets, fast-food companies shape many of the cues in our everyday environment. While the ubiquity of fast food is undoubtedly driven by consumer demand for instant gratification, it may also play a role in exacerbating that very impatience — and not just for food, but in many facets of our lives. In a series of recent papers, I joined two of my colleagues at the University of Toronto, Julian House and Chen-Bo Zhong, in examining this question. We began our experiments by prompting participants with reminders of fast food, like pictures of fast-food logos or having them recall recent experiences of eating fast food. We then gave them a number of tasks to complete. Across several studies, we found that thoughts of fast food spurred participants to hurry through reading a paragraph describing their city; express a greater desire for timesaving products; report less happiness from savoring a beautiful opera duet; and save less for tomorrow. These findings — that our associations with fast food can induce greater impatience — are interesting in their own right, but they are especially important because of the pervasiveness of fast food in our modern environment. We also took our investigation a step further, to consider whether the prevalence of fast-food restaurants in our neighborhoods might undercut our well-being. There is a lengthy epidemiology literature demonstrating a link between the number of fast-food restaurants and obesity. While the consequences of fast food for our health seem quite obvious, we wondered what these same methods might reveal regarding impatience. © 2014 The New York Times Company

Keyword: Obesity
Link ID: 19680 - Posted: 06.02.2014

Learning a second language can have a positive effect on the brain, even if it is taken up in adulthood, a University of Edinburgh study suggests. Researchers found that reading, verbal fluency and intelligence were improved in a study of 262 people tested either aged 11 or in their seventies. A previous study suggested that being bilingual could delay the onset of dementia by several years. The study is published in Annals of Neurology. The big question in this study was whether learning a new language improved cognitive functions or whether individuals with better cognitive abilities were more likely to become bilingual. Dr Thomas Bak, from the Centre for Cognitive Ageing and Cognitive Epidemiology at the University of Edinburgh, said he believed he had found the answer. Using data from intelligence tests on 262 Edinburgh-born individuals at the age of 11, the study looked at how their cognitive abilities had changed when they were tested again in their seventies. The research was conducted between 2008 and 2010. All participants said they were able to communicate in at least one language other than English. Of that group, 195 learned the second language before the age of 18, and 65 learned it after that time. The findings indicate that those who spoke two or more languages had significantly better cognitive abilities compared to what would have been expected from their baseline test. The strongest effects were seen in general intelligence and reading. The effects were present in those who learned their second language early, as well as later in life. BBC © 2014

Keyword: Language; Alzheimers
Link ID: 19679 - Posted: 06.02.2014

Sarah C. P. Williams This, in all its molecular complexity, is what the bulging end of a single neuron looks like. A whopping 300,000 proteins come together to form the structure, which is less than a micrometer wide, hundreds of times smaller than a grain of sand. This particular synapse is from a rat brain. It’s where chemical signals called neurotransmitters are released into the space between neurons to pass messages from cell to cell. To create a 3D molecular model of the structure, researchers first isolated the synapses of rat neurons and turned to classic biochemistry to identify and quantify the molecules present at every stage of the neurotransmitter release cycle. Then, they used microscopy to pinpoint the location of each protein. Some proteins—like the red patches of SNAP25 visible in the video at 0:14—aid in the release of vesicles, tiny spheres full of neurotransmitters. Others—like the green, purple, and red rods at 0:45—help the synapse maintain its overall structure. Different proteins surround vesicles when they’re inside the synapse—the circles scattered throughout the structure at 0:56—than when the vesicles are forming at the edge of the synapse—as shown at 2:08. Researchers can use the model, described online today in Science, to better understand how neurons function and what goes wrong in brain disorders. (Video credit: Wilhelm et al. 2014, Science) © 2014 American Association for the Advancement of Science.

Keyword: Brain imaging
Link ID: 19678 - Posted: 05.31.2014

By NICHOLAS BAKALAR Several observational studies have suggested that drinking diet soda may encourage weight gain, but a new randomized trial finds that it is not so. The study, published in the June issue of Obesity and paid for by the American Beverage Association, suggests that diet drinks may be better for weight loss than plain water. The study tested 303 men and women who followed the same diet for 12 weeks. But half were randomly assigned to drink at least 24 ounces of water daily, and the rest the same amount of artificially sweetened drinks. After controlling for age, sex, ethnicity and initial weight and blood pressure, researchers found that those who drank diet drinks lost an average of 14.2 pounds, compared with a 10-pound loss for the water drinkers. The mechanism, the authors write, is unclear, but the group on diet drinks reported slightly lower scores on a questionnaire measuring the degree of feelings of hunger. “There’s no magic in diet soda,” said the lead author, James O. Hill, a professor of health and wellness at the University of Colorado. But the less intense feelings of hunger among the drinkers, he said, may have made it easier for them to adhere to the diet. “From everything we know about diet soda,” he continued, “this result was totally expected. There’s not a single randomized controlled trial that shows the opposite.” © 2014 The New York Times Company

Keyword: Obesity
Link ID: 19677 - Posted: 05.31.2014

by Laura Sanders Some people think marijuana is nature’s gift to humankind: a nonaddictive drug, safe at any dose, that opens the mind, lifts the spirit and transports the user to a more profound reality. “The illegality of cannabis is outrageous, an impediment to full utilization of a drug which helps produce the serenity and insight, sensitivity and fellowship so desperately needed in this increasingly mad and dangerous world,” a user named Mr. X wrote in the 1971 book Marihuana Reconsidered. Close to 30 years later, Mr. X was revealed to be the legendary science communicator and astronomer Carl Sagan. His message still reverberates with many Americans, whose support for legalizing marijuana has tripled since 1989 — from 16 percent to 54 percent today. In Colorado and Washington state, voters legalized recreational marijuana use in November 2012. That formal embrace of marijuana may signal a growing shift in acceptance. Today, 21 states and the District of Columbia sanction medical use (up from 16 in 2010) and 17 have curbed punishments for possession of small amounts of recreational cannabis. Marijuana as medicine is gaining support in studies, both to tamp down nausea and pain and to directly counter insidious diseases such as epilepsy, cancer and multiple sclerosis (SN: 6/19/10, p. 16). But what about for healthy people? Is marijuana really a safe way to rise above the tumult and distress of daily life? Michele Leonhart, the head of the U.S. Drug Enforcement Administration, says no. In congressional testimony in 2012, she portrayed marijuana as a dangerous addictive drug on par with methamphetamines or heroin. Like other drugs cordoned off by her agency to a list called Schedule I, she said, marijuana has no medical use and a high potential for abuse. © Society for Science & the Public 2000 - 2013.

Keyword: Drug Abuse
Link ID: 19676 - Posted: 05.31.2014

Elizabeth Norton It's a sad fact that children born in poverty start out at a disadvantage and continue to fall further behind kids who are more privileged as they grow up. In developing countries, chiefly in Africa and Asia, some 200 million children under age 5 won't reach the same milestones—for physical growth, school performance, and earnings later on—as children who are less deprived. But a new analysis of a long-term study in Jamaica shows that surprisingly simple ways of stimulating children’s mental development can have dramatic benefits later in life. The children were participants in the Jamaican Study, a project geared toward improving cognitive development begun in the mid-1980s by child health specialists Sally Grantham-McGregor of University College London and Susan Walker of the University of the West Indies, Mona, in Jamaica. They focused on children between the ages of 9 and 24 months whose growth was stunted, placing them in the bottom 5% of height for their age and sex (an easy-to-quantify gauge of extreme poverty). Children of normal height in the same neighborhoods were also studied for comparison. For 2 years, community health workers visited the families weekly. One group was given nutritional assistance only (a formula containing 66% of daily recommended calories, along with vitamins and minerals). One group received a mental and social stimulation program only, and one group got stimulation and nutritional assistance. A final group had no intervention and served as a control. The mental stimulation program involved giving parents simple picture books and handmade toys, and encouraging them to read and sing to their children and point out names of objects, shapes, and colors. They were also taught better ways to converse and respond to their toddlers. These everyday interactions aren't always part of the culture in low-income countries, explains Paul Gertler, an economist at the University of California, Berkeley. "Parents might have five or six kids and few toys. They might be working really hard and have a lot of competing demands. They might not have been taught how to talk to their children, or how important and effective it is," he says. Past research attests to the importance of everyday conversation for children’s mental development: A recent study suggests that children of affluent parents do better in life in large part because their parents talk to them more. © 2014 American Association for the Advancement of Science

Keyword: Development of the Brain; Learning & Memory
Link ID: 19675 - Posted: 05.31.2014

Jyoti Madhusoodanan Most people handle stress well, but some find it difficult to cope and as a result develop depression and other mood disorders. Researchers have previously been able to identify the part of the brain that controls this response, but not exactly how it does so. Now, a study in mice identifies a small group of neurons that could be responsible. The research might also help elucidate the mechanism of deep brain stimulation, a therapy that uses electrical impulses to treat depression and other neurological disorders. How an animal deals with stress is controlled by a part of the brain known as the prefrontal cortex, and the neurons in this part of the brain are known to change in structure and function in response to stressful situations1. To look at the cellular basis of the responses, neuroscientist Bo Li of Cold Spring Harbor Laboratory in New York and his colleagues subjected mice to small electric shocks at random intervals to produce stress. Most of the mice tried to avoid the shocks, but just over one-fifth did not. They also started to avoid other animals or failed to choose tasty foods over plain ones — typical signs of depressive behaviour. The researchers then looked at the animals' brains and found that a specific set of neurons in the prefrontal cortex were easily excitable in depressed mice, but much harder to excite in those resilient to the stress. Furthermore, artificially increasing the activity of these neurons caused mice that were once resilient to become susceptible to depressive behaviours. “We were surprised that we were able to see a difference between depressed and resilient animals at the level of synaptic transmission,” says Li. © 2014 Nature Publishing Group,

Keyword: Depression; Stress
Link ID: 19674 - Posted: 05.31.2014

By NICHOLAS BAKALAR The hormone estrogen is the recommended treatment for menopausal night sweats and hot flashes, but some women are unable or unwilling to use it. Now a clinical trial suggests that the antidepressant venlafaxine, often used as an alternative, is equally effective. In an eight-week placebo-controlled double-blind study, researchers randomly assigned 339 perimenopausal and postmenopausal women to one of three treatments: 0.5 milligrams a day of estrogen (in the form of estradiol), 75 milligrams a day of the antidepressant venlafaxine (a generic form of Effexor), or a placebo. Before the start of the study, all the women had had symptoms at least 14 times a week. Compared to the rate before the study — an average of 8.1 episodes a day — the frequency of hot flashes and night sweats declined by 52.9 percent in the estradiol group, 47.6 percent in the Effexor group, and 28.6 percent among those who took a placebo. Both Effexor and estradiol were effective treatments, but the study, published online in JAMA Internal Medicine, was not large enough to show that one was significantly better than the other. “Women have important choices of different medications to discuss with their doctors,” said the lead author, Dr. Hadine Joffe, an associate professor of psychiatry at Harvard. “They should know, as they think about these options, that both are effective.” © 2014 The New York Times Company

Keyword: Hormones & Behavior
Link ID: 19673 - Posted: 05.31.2014

By Denali Tietjen If you watch porn, you probably have a small brain, a new study published in the Journal of the American Medical Association (JAMA) shows. The study, conducted by the Max Plank Institute for Human Development in Berlin, found a significant negative correlation between frequent pornography consumption and grey matter in the brain (that’s the stuff that tells your brain how to react to sensory information.) The keyword here is correlation. While the study’s findings are significant, the researchers don’t know if it’s the porn that causes the low grey-matter volume in porn-watchers, or if it’s the other way around. It could be a neurological pre-condition that makes watching porn particularly satisfying. However, researchers have reason to believe that porn does negatively impact the brain. Previous research proves that frequent porn consumption can cause negative social behavior. Porn consumption can cause viewers to be less satisfied during sex and viewers often want to adopt acts they’ve seen in illegal pornography, according to the report. If porn can affect social behavior, it can probably affect cognitive behavior, too. The study examined the cognitive structure of 64 males ages 21 to 45 years old that consumed porn at varying levels of frequency. While few people openly admit to watching porn, 66 percent of all men and 41 percent of American women view pornography at least once a month, and an estimated 50 percent of internet traffic is sex-related, according to the journal.

Keyword: Sexual Behavior; Brain imaging
Link ID: 19672 - Posted: 05.31.2014