By Jocelyn Kaiser Researchers have used a modified AIDS virus to halt a devastating brain disease in two young boys. The treatment, in which the virus delivered a therapeutic gene, marks the first time gene therapy has been successfully used against X-linked adrenoleukodystrophy (ALD)--a disorder that is always fatal if untreated. With this proof of principle, scientists hope versions of the AIDS virus engineered to carry different genes can now be applied to a variety of other diseases. ALD is caused by a defect in an X chromosome gene that produces a protein called ALD. Cells need this transporter protein to break down certain fats; without it, the fats build up and damage the myelin sheathing that protects nerves. In X-linked ALD, which strikes mainly boys, patients develop neurological symptoms such as seizures and loss of vision around age 6 to 8, and within months they become paralyzed, deaf, and eventually die. In the 1980s, the parents of a boy with ALD developed a mixture of fatty acids they called Lorenzo's oil that may have delayed the disease in their son (and inspired a 1992 movie). But the only widely accepted way to stave off ALD is a bone marrow transplant, which is risky--20% to 30% of patients die or have serious complications--and works best if the donor marrow comes from a sibling. In search of an alternative, pediatrician Patrick Aubourg of INSERM in Paris, the French biomedical research agency, and the University Paris-Descartes, along with collaborators in France and Germany, tried gene therapy on two 7-year-olds with ALD who couldn't be matched with a bone marrow donor. They removed blood cells from each boy and treated the cells with a so-called lentiviral vector, a modified HIV virus carrying the gene for the enzyme they lacked. The virus could not replicate, but it stitched the gene into the DNA of the blood cells. © 2009 American Association for the Advancement of Science

Keyword: Genes & Behavior; Development of the Brain
Link ID: 13436 - Posted: 06.24.2010

By Rachel Ehrenberg The safe answer to how a lantern shark turns its luminescence on and off is: “Any way it wants.” Now researchers have looked into the belly of the beast and found that three hormones act as on-off switches for these glow-in-the-dark sharks. It is the first discovery of hormones controlling bioluminescence in animals, the scientists report in the Nov. 15 Journal of Experimental Biology. Belgian researchers identified melatonin, prolactin and alpha-MSH, three hormones known to control sharkskin coloration, as key players in setting sharks aglow. In all animals investigated up to this point, luminescence is triggered by nerve cells. Finding a parallel pathway to bioluminescence — one that’s controlled by hormones, not nerves — strongly supports the notion that light-emitting powers have evolved multiple times in animals, comments marine scientist Jim Gelsleichter of the University of North Florida in Jacksonville, who was not involved in the research. access The light-emitting cells in some sharks aren’t connected to prominent nerve cells, and the slow onset of their glow hinted that something other than nerves were involved. Exposing patches of skin from lantern sharks to hormones and to nerve signaling molecules confirmed that hormones turn on the sharks’ bluish glow. Melatonin, which in humans is an important hormone for sleep regulation, induced a slow, long-lasting glow in the skin patches that persisted for several hours, researchers show. © Society for Science & the Public 2000 - 2009

Keyword: Hormones & Behavior; Animal Communication
Link ID: 13435 - Posted: 06.24.2010

by Maia Szalavitz Many millions have been made in Hollywood by lampooning the acute effects of marijuana on memory—but Israeli researchers suggest that they might one day be harnessed to prevent or treat post-traumatic stress disorder (PTSD). And today's election results bringing medical marijuana dispensaries to yet another state suggest that day might be sooner than ever. A new study—published in the Journal of Neuroscience—found that a synthetic drug that acts like one of the active components in marijuana (THC) can prevent stress-induced enhancement of fear memories in rats. PTSD is basically a syndrome in which fear-filled memories intrude on daily life and sleep—so preventing stress from strengthening memories of fear could potentially prevent or treat it. In the study, the rats were trained to fear a dark region of a cage where they received electric shocks. Though rats normally prefer dark places, they learned to stay in the light and avoid the now-scary dark area. When researchers stopped giving shocks in the dark region, rats slowly learned that it was safe again and began to return to it. The researchers measured how long this took. During the next experiment on a new group of rats, the experience was made more stressful. Now, rats were placed on an elevated grid after receiving the shock. Rats-- and most other animals, including many humans--tend to avoid walking over elevated grids if they can, and find being forced to do so distressing. As expected, the researchers found that it took longer for these rats to learn that the dark region was safe again. © 2009 Time Inc.

Keyword: Stress; Learning & Memory
Link ID: 13434 - Posted: 06.24.2010

Cristen Conger, HowStuffWorks.com -- The first detailed anatomical atlas of a living wildlife species has been constructed by researchers. Mapping the California sea lion's (Zalophus californianus) brain with a combination of magnetic resonance imaging (MRI) and volumetric measuring, scientists want to better understand how toxins in the water are causing neurological damage among marine mammal populations. Eric Montie, a postdoctoral researcher at the University of South Florida, spearheaded the study, which was published in The Anatomical Record in October. The brain atlas is a first step toward determining whether exposure to manmade chemicals, such as DDT and polychlorinated biphenyls (PCBs), increase California sea lions' susceptibility to life-threatening brain damage from domoic acid, a neurotoxin naturally produced by certain types of algae. Past studies have concluded that domoic acid, which accumulates in the sea lion's system from ingesting prey that feed on algae, causes the mammal's hippocampus to shrink. Research has also linked domoic acid to acute and chronic epilepsy and seizures in sea lions. But exactly how that neurotoxin-induced brain damage progresses is still unclear. sea lion "We don't know enough about the endocrinology and neurobiology of these animals," Montie told Discovery News. "That's why you start with baby steps like an atlas." © 2009 Discovery Communications, LLC.

Keyword: Neurotoxins; Development of the Brain
Link ID: 13433 - Posted: 06.24.2010

Female fiddler crabs have sex with their male neighbours in exchange for protection against wandering male intruders, say Australian researchers. A team led by Patricia Backwell of the Australian National University report their argument in the Royal Society journal Biology Letters. Both male and female fiddler crabs shelter in burrows, which they both must defend from intruders. But while males have an extremely large claw that can be used as a weapon, female crabs have just two small feeding claws. So how do female crabs defend their territory? To answer this question Backwell and colleagues built on previous work showing that under certain circumstances, males will help protect a neighbouring male from an intruder. Such "defensive coalitions" are rare in the animal kingdom and have so far only been demonstrated in two species of fiddler crab and a type of bird called a rock pipit. Protecting a neighbour can be risky, leading to injury, loss of a claw and even death, and a male also risks having his own unattended burrow invaded while off protecting a neighbour. However, team member and behavioural ecologist Michael Jennions says it's a case of better the enemy you know. © CBC 2009

Keyword: Sexual Behavior; Evolution
Link ID: 13432 - Posted: 06.24.2010

By Lindsey Konkel and Environmental Health News Seeking healthful foods, Americans are eating more soy than ever. But recent research with animals shows that consuming large amounts could have harmful effects on female fertility and reproductive development. Soy is ubiquitous in the American diet. Over a quarter of all infant formula sold is made with it, and the U.S. Food and Drug Administration promotes it in foods to reduce the risk of heart disease. School lunch programs across the country are even adding soy to hamburger patties. Many of soy’s health benefits have been linked to isoflavones—plant compounds that mimic estrogen. But animal studies suggest that eating large amounts of those estrogenic compounds might reduce fertility in women, trigger premature puberty and disrupt development of fetuses and children. Although most studies looking at the hormone-disrupting properties of genistein, the main isoflavone in soy, have been conducted in rodents, many scientists believe the findings may be relevant to humans as well. “We know that too much genistein is not a good thing for a developing mouse; it may not be a good thing for a developing child,” said Retha Newbold, a developmental biologist at the National Institute of Environmental Health Sciences. More definitive answers, she said, may lay ahead in future long-term human studies. © 1996-2009 Scientific American Inc.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 13431 - Posted: 06.24.2010

Juggling and other physically complex activities may hold some promise for brain regeneration among those who have suffered stroke or are coping with other neurological diseases where the pathways that connect how people think with how they move their bodies begin to break down. Researchers at Britain's University of Oxford used diffusion, a new type of magnetic resonance imaging, to compare the physical structure of white matter -- the nerve fibers that connect parts of the brain -- in a control group of 24 men and women to a second group of 24 who had practiced juggling for 30 minutes a day for six weeks. The MRIs showed an increase in white matter among the jugglers, regardless of their skill level. And the increase persisted even after the juggling sessions ended. Scientists have long known that gray matter, where the brain processes information, increases when people tackle new tasks or have new experiences. But this was the first time researchers have shown that white matter can increase, too, according to Heidi Johansen-Berg, an Oxford neuroscientist and lead author of the study, which was published in the journal Nature Neuroscience. In an e-mail she said, "Gray matter consists of neurons, which can be thought of as computation units, processing and integrating the incoming information. White matter, on the other hand, is composed of the connections between different areas." Johansen-Berg said the MRIs only revealed that the white matter area of the brain had changed. "The findings may have a clinical relevance in the future -- but that would be a long way down the line. There are a number of brain diseases, such as multiple sclerosis, that result in degeneration of pathways. Our results show that, in healthy adults, those pathways can change positively as a result of training," she said. "Future therapies might try to use training regimes or drugs to enhance such positive changes in disease, to counteract degeneration." © 2009 The Washington Post Company

Keyword: Learning & Memory
Link ID: 13430 - Posted: 06.24.2010

by Michael Bond IS GEORGE W. BUSH stupid? It's a question that occupied a good many minds of all political persuasions during his turbulent eight-year presidency. The strict answer is no. Bush's IQ score is estimated to be above 120, which suggests an intelligence in the top 10 per cent of the population. But this, surely, does not tell the whole story. Even those sympathetic to the former president have acknowledged that as a thinker and decision-maker he is not all there. Even his loyal speechwriter David Frum called him glib, incurious and "as a result ill-informed". The political pundit and former Republican congressman Joe Scarborough accused him of lacking intellectual depth, claiming that compared with other US presidents whose intellect had been questioned, Bush junior was "in a league by himself". Bush himself has described his thinking style as "not very analytical". How can someone with a high IQ have these kinds of intellectual deficiencies? Put another way, how can a "smart" person act foolishly? Keith Stanovich, professor of human development and applied psychology at the University of Toronto, Canada, has grappled with this apparent incongruity for 15 years. He says it applies to more people than you might think. To Stanovich, however, there is nothing incongruous about it. IQ tests are very good at measuring certain mental faculties, he says, including logic, abstract reasoning, learning ability and working-memory capacity - how much information you can hold in mind. But the tests fall down when it comes to measuring those abilities crucial to making good judgements in real-life situations. That's because they are unable to assess things such as a person's ability to critically weigh up information, or whether an individual can override the intuitive cognitive biases that can lead us astray. © Copyright Reed Business Information Ltd

Keyword: Intelligence
Link ID: 13429 - Posted: 06.24.2010

By PAM BELLUCK By the time Corey Haas was 7, the retinal disease he was born with had already stolen much of his vision. “He always clung to me or my wife,” said Corey’s father, Ethan Haas. The boy relied on a cane and adults to guide him, and, unable to see blackboard writing, sat in back with a teacher’s aide, large-type computer screen and materials in Braille. Legally blind, Corey was expected eventually to lose all sight. Then, 13 months ago, after his eighth birthday, he underwent an experimental gene therapy procedure, receiving an injection in his left eye. His vision in that eye improved quickly. Now 9, Corey plays Little League baseball, drives go-carts, navigates wooded trails near his home in Hadley, N.Y., and reads the blackboard in class. “It’s gotten, like, really better,” he said. Experts in vision problems say that while it is unclear how many visually impaired people gene therapy could help, they consider the research promising for some types of blinding diseases, and an achievement for gene therapy, which has had many setbacks. The study, reported in the journal Lancet, involved five children and seven adults, from Belgium, Italy and the United states, with a type of Leber’s congenital amaurosis, rare but serious congenital retinal diseases. Copyright 2009 The New York Times Company

Keyword: Vision; Genes & Behavior
Link ID: 13428 - Posted: 06.24.2010

By CLAUDIA WALLIS It is one of the most intriguing labels in psychiatry. Children with Asperger’s syndrome, a mild form of autism, are socially awkward and often physically clumsy, but many are verbal prodigies, speaking in complex sentences at early ages, reading newspapers fluently by age 5 or 6 and acquiring expertise in some preferred topic — stegosaurs, clipper ships, Interstate highways — that will astonish adults and bore their playmates to tears. In recent years, this once obscure diagnosis, given to more than four times as many boys as girls, has become increasingly common. Much of the growing prevalence of autism, which now affects about 1 percent of American children, according to federal data, can be attributed to Asperger’s and other mild forms of the disorder. And Asperger’s has exploded into popular culture through books and films depicting it as the realm of brilliant nerds and savantlike geniuses. But no sooner has Asperger consciousness awakened than the disorder seems headed for psychiatric obsolescence. Though it became an official part of the medical lexicon only in 1994, the experts who are revising psychiatry’s diagnostic manual have proposed to eliminate it from the new edition, due out in 2012. If these experts have their way, Asperger’s syndrome and another mild form of autism, pervasive developmental disorder not otherwise specified (P.D.D.-N.O.S. for short), will be folded into a single broad diagnosis, autism spectrum disorder — a category that encompasses autism’s entire range, or spectrum, from high-functioning to profoundly disabling. Copyright 2009 The New York Times Company

Keyword: Autism
Link ID: 13427 - Posted: 06.24.2010

by Olivia Judson Say “eeee.” Say it again. Go on: “eeee.” Maybe I’m easy to please, but doing this a few times makes me giggle. “Eeee.” Actually, I suspect it’s not just me. Saying “eeee” pulls up the corners of the mouth and makes you start to smile. That’s why we say “cheese” to the camera, not “choose” or “chose.” And, I think, it’s why I don’t get the giggles from “aaaa” or “oooo.” The mere act of smiling is often enough to lift your mood; conversely, the act of frowning can lower it; scowling can make you feel fed up. In other words, the gestures you make with your face can — at least to some extent — influence your emotional state. Exactly how frowns and smiles influence mood is a matter of debate. One possibility is classical conditioning. Just as Ivan Pavlov conditioned a dog to associate the sound of a bell with the expectation of food, the argument goes, so humans quickly come to associate smiling with feeling happy. Once the association has been established, smiling is, by itself, enough to generate happy feelings. Another possibility is that different facial gestures have intrinsic properties that make them more or less pleasant, perhaps by altering the way that blood flows to the brain. Copyright 2009 The New York Times Company

Keyword: Emotions
Link ID: 13426 - Posted: 06.24.2010

By Diane Welland The push to prevent skin cancer may have come with unintended consequences—impaired brain function because of a deficiency of vitamin D. The “sunshine vitamin” is synthesized in our skin when we are exposed to direct sunlight, but sunblock impedes this process. And although vitamin D is well known for promoting bone health and regulating vital calcium levels—hence its addition to milk—it does more than that. Scientists have now linked this fat-soluble nutrient’s hormonelike activity to a number of functions throughout the body, including the workings of the brain. “We know there are receptors for vitamin D throughout the central nervous system and in the hippocampus,” said Robert J. Przybelski, a doctor and research scientist at the University of Wisconsin School of Medicine and Public Health. “We also know vitamin D activates and deactivates enzymes in the brain and the cerebrospinal fluid that are involved in neurotransmitter synthesis and nerve growth.” In addition, animal and laboratory studies suggest vitamin D protects neurons and reduces inflammation. Two new European studies looking at vitamin D and cognitive function have taken us one step further. The first study, led by neuroscientist David Llewellyn of the University of Cambridge, assessed vitamin D levels in more than 1,700 men and women from England, aged 65 or older. Subjects were divided into four groups based on vitamin D blood levels: severely deficient, deficient, insufficient (borderline) and optimum, then tested for cognitive function. © 1996-2009 Scientific American Inc

Keyword: Hormones & Behavior
Link ID: 13425 - Posted: 06.24.2010

By Lone Frank Say the word: neuromarketing. Doesn’t exactly sound good, does it? It’s an outlandish word that scrapes across the tongue, leaving an aftertaste of thought control, science fiction, and downright creepiness. The press surrounding neuromarketing reflects this as well. The headlines are ominous: soon, the bright boys of the advertising world will get their sticky hands on our inner "buy button." Soon, marketing experts, with the help of cutting-edge brain research, will get direct access to the inner depths of our brains where, with the right stimulation, they can unleash our buying impulses and get their cash registers ringing. Neuromarketing is a young and growing field–some won’t even admit that it is a field yet–that is striving to reveal the inner mechanisms of our consumer behavior. You might say that this interest and the issues it raises are a natural extension or offshoot of neuroeconomics and the more general studies of how we make choices and decisions. Every so often, there is also a conspicuous overlap between neuroeconomists and researchers in neuromarketing. The studies in neuromarketing are just more specific and much more directed. And the Holy Grail lies in predicting what the brain wants. In the advertising industry, you can see neuromarketing as an attempt to make the "art" of advertising into a science Any marketing expert proposing a multi-million dollar project to a client would like to be able to back it up with something that looks like real data, not just hunches. © 1996-2009 Scientific American Inc.

Keyword: Emotions
Link ID: 13424 - Posted: 06.24.2010

By Piercarlo Valdesolo The power to resist temptation has been extolled by philosophers, psychologists, teachers, coaches, and mothers. Anyone with advice on how you should live your life has surely spoken to you of its benefits. It is the path to the good life, professional and personal satisfaction, social adjustment and success, performance under pressure, and the best way for any child to avoid a penetrating stare and a cold dinner. Of course, this assumes that our natural urges are a thing to be resisted – that there is a devil inside, luring you to cheat, offend, err, and annoy. New research has begun to question this assumption. A new brain imaging study by Josh Greene and Joe Paxton at Harvard University published in the Proceedings of the National Academy of Sciences suggests that what separates the well-behaved from the poorly-behaved might not be the ability to control your temptations but rather what kind of temptations you have. For example, foregoing the opportunity for short-term gain and satisfaction, whether it is a delicious slice of tiramisu or that wallet stuffed with cash you stumbled across in the empty parking lot, will depend more on the nature of your automatic urges than your ability to control them. Greene and Paxton were interested in why people behave honestly when confronted with the opportunity to anonymously cheat for personal gain. They considered two possible explanations. First, there is the “Will” hypothesis: in order to behave honestly people must actively resist the temptation to cheat. In other words, returning the wallet depends on your ability to stifle your desire to take the cash and buy yourself something nice. Alternatively, there is the “Grace” hypothesis: honest behavior results from the absence of temptation. Returning the wallet requires no particular ability to control your treacherous urges – the urge simply isn’t there. © 1996-2009 Scientific American Inc.

Keyword: Emotions
Link ID: 13423 - Posted: 06.24.2010

By Greg Miller "I think, therefore I am," pronounced the famed French philosopher René Descartes. What imbues us with this uniquely human sense of self-awareness? Some neuroscientists have pegged an area of the brain known as the insula, which helps us detect what's going on within our bodies. But an unusual case of a man with extensive damage to this region suggests that the insula cannot be the sole source of self-awareness. Tucked deep inside the brain, the insula responds to pain, a full stomach, changes in body temperature, and other internal sensations. Researchers have proposed that the insula somehow translates these visceral sensations into conscious, subjective experience. But it's a hard hypothesis to test. Enter "Roger." In 1980, a viral disease known as herpes simplex encephalitis destroyed 25% to 35% of his brain, including nearly all of his insula. Yet Roger functions remarkably well: Although he suffers from amnesia and has lost his sense of smell and taste, he has a normal IQ and very good language skills. Roger doesn't act like he lacks self-awareness, but researchers led by Sahib Khalsa and David Rudrauf of the University of Iowa in Iowa City were curious about his ability to detect visceral sensations. To investigate, they gave Roger a drug that increases heart rate. Then they asked him to turn a dial to indicate any changes he noticed. Roger detected the increase, as did 11 healthy volunteers. © 2009 American Association for the Advancement of Science.

Keyword: Attention
Link ID: 13422 - Posted: 06.24.2010

Eating a diet high in processed food increases the risk of depression, research suggests. What is more, people who ate plenty of vegetables, fruit and fish actually had a lower risk of depression, the University College London team found. Data on diet among 3,500 middle-aged civil servants was compared with depression five years later, the British Journal of Psychiatry reported. The team said the study was the first to look at the UK diet and depression. They split the participants into two types of diet - those who ate a diet largely based on whole foods, which includes lots of fruit, vegetables and fish, and those who ate a mainly processed food diet, such as sweetened desserts, fried food, processed meat, refined grains and high-fat dairy products. After accounting for factors such as gender, age, education, physical activity, smoking habits and chronic diseases, they found a significant difference in future depression risk with the different diets. Those who ate the most whole foods had a 26% lower risk of future depression than those who at the least whole foods. By contrast people with a diet high in processed food had a 58% higher risk of depression than those who ate very few processed foods. Although the researchers cannot totally rule out the possibility that people with depression may eat a less healthy diet they believe it is unlikely to be the reason for the findings because there was no association with diet and previous diagnosis of depression. Study author Dr Archana Singh-Manoux pointed out there is a chance the finding could be explained by a lifestyle factor they had not accounted for. BBC © MMIX

Keyword: Depression
Link ID: 13421 - Posted: 06.24.2010

An Italian court has cut the sentence given to a convicted murderer by a year because he has genes linked to violent behaviour — the first time that behavioural genetics has affected a sentence passed by a European court. But researchers contacted by Nature have questioned whether the decision was based on sound science. Abdelmalek Bayout, an Algerian citizen who has lived in Italy since 1993, admitted in 2007 to stabbing and killing Walter Felipe Novoa Perez on 10 March. Perez, a Colombian living in Italy, had, according to Bayout's testimony, insulted him over the kohl eye make-up the Algerian was wearing. Bayout, a Muslim, claims he wore the make-up for religious reasons. During the trial, Bayout's lawyer, Tania Cattarossi, asked the court to take into account that her client may have been mentally ill at the time of the murder. After considering three psychiatric reports, the judge, Paolo Alessio Vernì, partially agreed that Bayout's psychiatric illness was a mitigating factor and sentenced him to 9 years and 2 months in prison — around three years less than Bayout would have received had he been deemed to be of sound mind. But at an appeal hearing in May this year, Pier Valerio Reinotti, a judge of the Court of Appeal in Trieste, asked forensic scientists for a new independent psychiatric report to decide whether he should commute the sentence further. For the new report, Pietro Pietrini, a molecular neuroscientist at Italy's University of Pisa, and Giuseppe Sartori, a cognitive neuroscientist at the University of Padova, conducted a series of tests and found abnormalities in brain-imaging scans and in five genes that have been linked to violent behaviour — including the gene encoding the neurotransmitter-metabolizing enzyme monoamine oxidase A (MAOA). A 2002 study led by Terrie Moffitt, a geneticist at the Institute of Psychiatry, King's College, London, had found low levels of MAOA expression to be associated with aggressiveness and criminal conduct of young boys raised in abusive environments. © 2009 Nature Publishing Group,

Keyword: Aggression; Genes & Behavior
Link ID: 13420 - Posted: 06.24.2010

By Richard Alleyne, Science Correspondent One of the charms of the world's most famous painting is that she appears radiant one moment and then serious and sardonic the next. Now scientists claim to have come up with an answer to her changing moods - our eyes are sending mixed signals to the brain. They believe Mona Lisa's smile depends on what cells in the retina pick up the image and what channel the image is transmitted through in the brain. Sometimes one channel wins over the other, and you see the smile, sometimes others take over and you do not see the smile. Different cells in the eye are designed to pick up different colours, contrasts, backgrounds and foregrounds. Some deal with central vision while others with peripheral. Depending on what cells picks up the image first depends on what channel they are sent to the brian for interpreting. These channels encode data about an object's size, clarity, brightness and location in the visual field. "Sometimes one channel wins over the other, and you see the smile, sometimes others take over and you don't see the smile," said Dr Luis Martinez Otero, a neuroscientist at Institute of Neuroscience in Alicante, Spain, who conducted the study, told New Scientist. To get a fuller picture of the reasons behind Mona Lisa's vanishing smile, Dr Martinez Otero varied different aspects of the Mona Lisa that are processed by different visual channels, and then asked volunteers whether they saw a smile or not. © Copyright of Telegraph Media Group Limited 2009

Keyword: Vision; Emotions
Link ID: 13419 - Posted: 06.24.2010

By Carolyn Y. Johnson As a child, Kathy Sherman used to sneak into the basement late at night to watch movies that scared her so much she couldn’t sleep. Now she’s a florist during the day, but on her own time Sherman organizes meetings of horror fans and visits haunted houses. She has tried bungee jumping and skydiving. “Oh my God - being scared, you can feel your heart pounding out of your chest, your skin feels like it’s getting goose bumps, your hair feels like it’s standing up, you jump out of your seat. You get all hyped up and you come back down. It’s just fun,’’ said Sherman, a resident of Randolph. To neuroscientists, Sherman is describing classic fear, the same emotion that primes the body to flee or fight predators, and that, when it goes terribly awry, causes disabling anxiety disorders or phobias. So as children and grownups alike celebrate all things frightful this Halloween, the question arises: Why do Kathy Sherman and so many of us indulge in fear for fun? The National Institutes of Health doesn’t give out million-dollar grants to better understand why people enjoy haunted houses or vampire movies, but scientists who study the biology of fear say their work suggests that the rush of hormones and the heart-racing thrill produce a sensation of pleasure while another part of the brain kicks in to let people know they won’t get hurt. “In the case of people who are thrill seekers . . . when they encounter something scary or bad, they’re going to have this endorphin rush. But there’s also a part of the brain that knows it’s not really a bad thing,’’ said neuroscientist Ki Ann Goosens of the McGovern Institute for Brain Research at MIT. © 2009 NY Times Co.

Keyword: Emotions
Link ID: 13418 - Posted: 06.24.2010

By Cassandra Willyard Think back to high school biology. Remember the long, stringy neurons that make up your nervous system? You probably learned that these cells communicate by sending a chemical message across the small gap between them, called a synapse. That's still true, but new research shows that certain brain cells bypass the synapse altogether. Instead, they communicate by spraying a cloud of neurotransmitters into the spaces between cells, blanketing nearby neurons. A team of Hungarian researchers at the University of Szeged made the discovery by examining a type of neuron called a neurogliaform cell. These cells are common in the brain's cortex, a region that plays a key role in many functions, including memory, attention, awareness, and language. Studies have shown that neurogliaform cells can inhibit the firing of other brain cells by releasing a neurotransmitter called GABA (gamma-aminobutyric acid), which typically transmits messages across synapses. But some studies have suggested that GABA can diffuse into the extracellular space as well, where it carries messages between neurons not connected via synapses. To create enough ambient GABA for this to happen, however, scientists speculated that many neurons would have to fire at once. The researchers set out to test this idea. The output end, or axon, of a normal neuron is typically long and stringy. But when the Hungarian team used electron and light microscopes to examine brain tissue from rats and humans, they found that neurogliaform cells have bushy axons with many branches. These bushy axons are densely populated with sites where GABA can be released into the extracellular space, the team found. Elsewhere in the brain this occurs mainly at synapses, but only 11 of the 50 release sites examined in neurogliaform cells corresponded to a synapse, the researchers report today in Nature. © 2009 American Association for the Advancement of Science.

Keyword: Glia
Link ID: 13417 - Posted: 06.24.2010