For the first time, investigators have identified a way to detect neural progenitor cells (NPCs), which can develop into neurons and other nervous system cells, in the living human brain using a type of imaging called magnetic resonance spectroscopy (MRS). The finding, supported by the National Institutes of Health (NIH), may lead to improved diagnosis and treatment for depression, Parkinson's disease, brain tumors, and a host of other disorders. Research has shown that, in select brain regions, NPCs persist into adulthood and may give rise to new neurons. Studies have suggested that the development of new neurons from NPCs, called neurogenesis, is disrupted in disorders ranging from depression and schizophrenia to Parkinson's disease, epilepsy, and cancer. Until now, however, there has been no way to monitor neurogenesis in the living human brain. "The recent finding that neural progenitor cells exist in adult human brain has opened a whole new field in neuroscience. The ability to track these cells in living people would be a major breakthrough in understanding brain development in children and continued maturation of the adult brain. It could also be a very useful tool for research aimed at influencing NPCs to restore or maintain brain health," says Walter J. Koroshetz, M.D., deputy director of the NIH's National Institute of Neurological Disorders and Stroke (NINDS), which helped fund the work. The study was also funded by the NIH's National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).

Keyword: Neurogenesis; Brain imaging
Link ID: 10950 - Posted: 11.09.2007

By Lisa Stein Reefer madness? Apparently not, according to a new Swiss survey of students that concludes teenagers who smoke pot function better than those who also use tobacco. In addition, researchers at the University of Lausanne report in the Archives of Pediatrics & Adolescent Medicine, teens who only use marijuana are apparently more socially driven and have no more psychosocial problems than those who neither smoke nor toke. The scientists surveyed 5,263 Swiss students (2,439 females) aged 16 to 20 years, including 455 who said they smoked weed only; 1,703 who reported being tobacco and marijuana users; and 3,105 who said they did not imbibe at all. "The gateway theory hypothesizes that the use of legal drugs (tobacco and alcohol) is the previous step to cannabis consumption," the authors wrote. "However, recent research also indicates that cannabis use may precede or be simultaneous to tobacco use and that, in fact, its use may reinforce cigarette smoking or lead to nicotine addiction independently of smoking status." Among their findings: Compared with students who reported using both drugs, those who smoked pot only were more likely to be male (71.6 percent versus 59.7 percent); get good grades (77.5 to 66.6 percent); play sports (85.5 to 66.7 percent); and live with both parents (78.2 to 68.3 percent). © 1996-2007 Scientific American, Inc.

Keyword: Drug Abuse
Link ID: 10949 - Posted: 06.24.2010

By Jennifer Couzin As they grow up, children with heart defects often suffer from learning and attention problems, as well as other cognitive and motor troubles. Now, a team of doctors has used sophisticated imaging on newborns with heart disease and found delayed brain development akin to what's seen in premature babies--a phenomenon that helps explain why infants with heart problems are at such high risk of brain injury. The work sheds new light on an emerging challenge in treating children with congenital heart disease. Heart surgery performed in the first weeks of life was initially eyed as the culprit behind learning, attention, and other cognitive problems. But a large study in Boston showed that even when a lower-risk form of cardiac bypass was used, babies still grew up to suffer cognitive deficits. Some studies have detected brain lesions or neurological abnormalities in newborns before heart surgery, but it wasn't clear whether these might account entirely for later cognitive deficits, either. To learn more, pediatric neurologist Steven Miller, now at the University of British Columbia in Vancouver and the University of California, San Francisco (UCSF), and Patrick McQuillen, a UCSF pediatric critical care specialist, along with their colleagues, performed sophisticated brain-imaging tests on 41 babies with congenital heart defects. They relied on traditional magnetic resonance imaging (MRI); magnetic resonance spectroscopy, which shows brain metabolism; and diffusion tensor imaging, which shows the brain's microstructure. The results were compared with those from 16 healthy, full-term babies. © 2007 American Association for the Advancement of Science

Keyword: Development of the Brain
Link ID: 10948 - Posted: 06.24.2010

A lot of people have come a lot of miles to attend this year’s SfN in San Diego. So perhaps I had travel in mind when I started off with a couple of posters loosely related to going places – admittedly on rather different scales… Firstly: getting around London by taxi. Eleanor Maguire and her student Katherine Woollett of University College London have been following up on Maguire’s previous – and rather well-publicised - study (Nature’s story at the time is here) on the brains of London cabbies. Back in 2000, they found that the size of a region called the hippocampus, which is involved in navigation and memory, is larger in London’s black cab drivers (who have to pass a foreboding test of the capital’s 25,000 streets, suitably titled The Knowledge) than in other people. Unfortunately for them, however, this expertise comes at a price to new learning and memory. A different part of the hippocampus actually decreases in size as a result of the enlargement of the rest of it. “It’s a story of loss and gain if you’re a taxi driver,” Maguire says. She wouldn’t be surprised, she told me, if this ‘give-and-take’ mechanism was being employed elsewhere in the brain too. Second travel titbit: getting humans to Mars. For completely different reasons, this form of transit might also impair your memory, as Bernard Rabin’s work on the effect of cosmic rays on rat’s brains suggests.

Keyword: Learning & Memory
Link ID: 10947 - Posted: 06.24.2010

Amid the dazzling high-tech displays of new-generation brain-machine interfaces (including brain implants with which monkeys can operate robotic arms) was a less glamorous but elegantly simple study which promises to improve quality of life for stroke victims, or victims of traumatic brain injury, whose ability to balance has been obliterated. Monica Metea of the company Wicab in Wisconsin displayed her company’s new balancing device BrainPort which has been through a pilot study of 17 patients, allowing them to stand, walk, dance without falling over. It works on the principle of brain plasticity. It’s a slim 2 cm square grid of 100 electrodes connected to a head position-detecting sensor which sits directly above them. The patients sticks the device in their mouths, and quickly learns from the pattern of the pinprick sensations delivered by the electrodes which way is up and which way is down. The brain also learns this in a physical sense. Somehow certain circuits get reconfigured such that even after the device is removed – after 20 minutes or so – the patient maintains his or her sense of balance, for hours, sometimes for days. No need to open up the skull and implant the device directly into delicate brain tissue like the more dramatic stories which will eventually help the paralysed. But applicable to probably millions of people who can’t stand up without falling over.

Keyword: Stroke
Link ID: 10946 - Posted: 06.24.2010

Matt Kaplan Antioxidants are all the rage, with research suggesting that they may help to prevent cancer, strokes and heart disease. Now a study highlights how these oxygen-mopping compounds affect more than just cellular health: they also seem to effect behaviour. Male three-spined stickleback fish (Gasterosteus aculeatus) fed on a high-antioxidant diet spend more time and energy fanning oxygen-rich water onto the eggs in their nest, researchers have found. The results aren’t entirely surprising, as an indirect link between diet, well-being and behaviour makes sense. “I would expect to see some behavioural changes from antioxidants through effects on body condition or immunocompetence,” says Ulrika Candolin, an ecologist at the University of Helsinki in Finland. “But this study suggests a direct pathway, which is interesting.” A lack of antioxidants seems to make the fish’s muscles tire more readily. Candolin says she thinks it is likely that behavioural changes would be seen in other animals deprived of antioxidants. But whether these changes are the result of fatigue or deteriorating health would require further study. © 2007 Nature Publishing Group

Keyword: Sexual Behavior
Link ID: 10945 - Posted: 06.24.2010

-- Japanese scientists have created genetically-modified mice that, shorn of their ability to sense dangerous smells, will even snuggle up to a kitten, according to a study released on Wednesday by the journal Nature. The mice were engineered to lack specific nasal receptors that respond to the scent of rotting food or predators, in a project designed to help understand the mechanisms of smell. The mice were able to detect these smells using other olfactory cells but, lacking the key pathway that triggered a "fear" warning to the brain, were quite undeterred by the presence of a cat or acids and other dangerous compounds. However, the mice could be conditioned into realizing that these smells meant danger, using classic laboratory methods of exposing them to the scents and to a painful irritant at the same time. The researchers, led by the University of Tokyo's Hitoshi Sakano, believe that the findings explain important differences in the olfactory bulb, the part of the forebrain where odors are perceived. © 2007 Discovery Communications

Keyword: Chemical Senses (Smell & Taste); Emotions
Link ID: 10944 - Posted: 06.24.2010

This week Mind Matters visits not just a particular paper, but the massive annual meeting of the Society for Neuroscience -- 30,000+ neuroscientists, scores of major lectures, hundreds of symposia, thousands and thousands of symposia and minisymposia. Scientific American has three people here, and we haven't a prayer -- way too many things to attend. Sorting out what to do next poses severe challenges to mechanisms of time management, executive function, attentional control, sleep-cycle adjustment, shoe quality, and memory. The variety of subjects covered is daunting and wonderful: how fasting can help you build brain cells; thought-controlled machines; how walnuts can make you smarter. Some notables so far: Classical music as antidepressant This study comes out of Alzahra University, in Tehran, where a group of researchers, noting that music therapy has already been shown to reduce pain, improve sleep quality, and improve mood in cancer patients underoing therapy and multiple sclerosis patients, wondered if music might alleviate depression as well. It does. They took 56 depressed subjects, had them listen to Beethoven's 3d and 5th piano sonatas for 15 minutes twice a week in a clean, otherwise quiet room -- and saw their depression scores on the standard Beck Depression Scale go up signficantly. No side effects! And music is cheap -- a lifetime of Beethoven for the price of a couple weeks of Prozac. Empathy (not) for sweethearts in pain A few weeks ago we ran reviews by Frans de Waal and Peggy Mason of a paper about mice showing empathy; the study found that mice viewing other mice in distress were more sensitive to pain themselves. Discouraging news, folks: A poster here at the meeting suggests that humans viewing their own spouses in pain may feel ... well, good. This one's still in the grain-of-salt department, mind you: It's a poster, which means it's on evidence still getting worked up and not yet peer-reviewed. But still: Yikes. © 1996-2007 Scientific American, Inc.

Keyword: Depression; Hearing
Link ID: 10943 - Posted: 06.24.2010

By Rob Stein Being overweight boosts the risk of dying from diabetes and kidney disease but not cancer or heart disease, and carrying some extra pounds actually appears to protect against a host of other causes of death, federal researchers reported yesterday. The counterintuitive findings, based on a detailed analysis of decades of government data about more than 39,000 Americans, supports the conclusions of a study the same group did two years ago that suggested the dangers of being overweight may be less dire than experts thought. "The take-home message is that the relationship between fat and mortality is more complicated than we tend to think," said Katherine M. Flegal, a senior research scientist at the Centers for Disease Control and Prevention in Atlanta, who led the study. "It's not a cookie-cutter, one-size-fits-all situation, where excess weight just increases your mortality risk for any and all causes of death." The study, published today in the Journal of the American Medical Association, was greeted with sharply mixed reactions. Some praised it for providing persuasive evidence that the dangers of fat have been overblown. "What this tells us is the hazards have been very much exaggerated," said Steven N. Blair, a professor of exercise science, epidemiology and biostatistics at the University of South Carolina. "It's just not as big a problem as people have said." © 2007 The Washington Post Company

Keyword: Obesity
Link ID: 10942 - Posted: 06.24.2010

Jennifer Viegas -- Sharks, rays and skates use a gel-like substance on their heads to pick up electrical current signals from their water environments, and possibly to follow a bloody trail, according to a new study. Since the process, known as electroreception, can override the animals' other senses, such as taste and smell, the discovery may help to explain why sharks pursue bloody victims, even when other "easy target" prey is around and the gushing blood obscures the shark's vision and smell. "The gel contains various proteins and salts, so it's similar to mucus, only with a jello-like consistency. Basically, it's shark snot," said lead author R. Douglas Fields. There are several reports of swimmers towing wounded buddies to shore, with the shark still going after the injured person instead of the rescuer, said Fields, who is chief of the Nervous System Development and Plasticity Section of the National Institutes of Health. "Bloody salts produce a strong electrical field that sharks can detect" with the gel, he explained. The findings, which have been accepted for publication in the journal Neuroscience Letters, negate a prior study that claimed shark gel serves as a semiconductor, meaning that it generates electricity in response to temperature changes. The author of that paper, B.R. Brown, agreed to issue a correction. © 2007 Discovery Communications

Keyword: Chemical Senses (Smell & Taste)
Link ID: 10941 - Posted: 06.24.2010

Debora MacKenzie It's official: you are more likely to think other people are attractive if they are looking straight at you and smiling. The finding helps to explain long-standing questions over the subtle ways in which evolution can determine human preferences. An important question in biology is whether a particular function or ability is the result of evolution or an accidental byproduct of it. Some biologists believe that human perception falls into this second category because there has been little evidence that how we perceive things like faces affects our biological success in ways that are selected for or against. But the evidence is mounting that evolution has conditioned our perception in subtle ways. Claire Conway and colleagues at the University of Aberdeen in Scotland, UK, paired nearly identical photos of computer-generated faces, with smiling or disgusted expressions. The pair differed only in where the irises were pointed: straight at the viewer, or off to the side (see image top right). Several hundred Aberdeen undergraduates, in the lab and online, rated the faces for sexual attractiveness, and for likeability, a sexually neutral quality. Both men and women found faces looking straight at them to be more attractive and more likeable, even if the faces looked disgusted though unsurprisingly, there was a greater preference for smiles. © Copyright Reed Business Information Ltd.

Keyword: Sexual Behavior; Emotions
Link ID: 10940 - Posted: 06.24.2010

Heidi Ledford It’s a common situation: you’re embroiled in an argument over a fact and you know for certain that you have the right answer. But when someone rushes to their laptop to google the correct answer, you discover that you were wrong. Whether in a fight with a spouse or giving testimony on the witness stand, it is clear that our memories are not always trustworthy. Now, researchers have found that although those vivid false memories may seem indistinguishable from true memories to you, but they are sometimes processed by different parts of the brain1. The results could one day be used to devise an early test for Alzheimer’s disease, or to assess the accuracy of witness testimony, says study author Roberto Cabeza, a neuroscientist at Duke University in Durham, North Carolina. Cabeza and Hongkeun Kim of Daegu University in South Korea asked 11 people to read lists of words that fall into a certain category, such as ‘farm animals’. The subjects were later asked whether specific words had occurred on the original lists, while functional magnetic resonance imaging was used to measure the changes in blood flow to different areas of their brains. The participants were also asked to say how confident they were in their answers. © 2007 Nature Publishing Group

Keyword: Learning & Memory
Link ID: 10939 - Posted: 06.24.2010

By Gretchen Vogel A burger, fries, and a double fudge sundae for dessert is probably not the best recipe for a good night's sleep. Indeed, a new study shows that in mice, high-fat diets seem to disrupt the body's natural day and night rhythms. The work may help scientists understand why obesity, diabetes, and sleep disruption are often intertwined in human patients. The body's daily rhythms are governed by the so-called circadian clock. The clock influences not only when we sleep but also when we get hungry and how efficiently our bodies process food. Several studies have shown that mutations in circadian clock genes can cause mice to gain weight (ScienceNOW, 21 April 2005). And humans deprived of sleep soon begin to overeat. But neurobiologist Joseph Bass and colleagues at Northwestern University in Evanston, Illinois, wondered if the connection worked the other way--whether diet could influence the clock. The researchers put mice on a high-fat diet and measured their activity and eating behavior throughout the day and the night, comparing the rodents to mice on regular rations. After a week of noshing on high-fat chow, the mice were more restless during daylight hours, when most mice are sleeping. And they seemed to have the mouse equivalent of midnight munchies: Mice on high-fat diets consumed nearly a third of their food during the daytime hours, whereas the control mice consumed only about 20% of their calories during the day, the team reports in the 7 November issue of Cell Metabolism. © 2007 American Association for the Advancement of Science.

Keyword: Biological Rhythms; Obesity
Link ID: 10938 - Posted: 06.24.2010

Alison Abbott Researchers have found a drug that can reduce aggressive behaviour in feral rats that have been trained to be violent. Although the find may not lead directly to a cure for pathological violence in humans, it does unpick a mechanism behind such violence, the researchers say, which could open the door to future treatments. Sietse de Boer and his colleagues from the University of Groningen in the Netherlands, who have developed the first animal model of pathological aggression, reported these findings at the Society for Neuroscience meeting in San Diego yesterday. Although violence is a serious societal problem, until now scientists have only been able to study 'normal' or 'appropriate' aggression in animals — such as fighting over limited resources of food or mates. Such studies are usually done using normal laboratory rodents, which have been bred over the decades to be docile and easier for researchers to handle. So the researchers decided to work with feral rats instead. Although a male rat will fight other males, it won’t attack females, preferring instead to court their sexual favours. It will also not fight with an anaesthetised 'intruder', recognising that it poses no threat. But de Boer was able to change this, training the rats to be gratuitously violent. © 2007 Nature Publishing Group

Keyword: Aggression
Link ID: 10937 - Posted: 06.24.2010

By JOHN TIERNEY For half a century, social psychologists have been trying to figure out the human gift for rationalizing irrational behavior. Why did we evolve with brains that salute our shrewdness for buying the neon yellow car with bad gas mileage? The brain keeps sending one message — Yesss! Genius! — while our friends and family are saying, “Well... ” This self-delusion, the result of what’s called cognitive dissonance, has been demonstrated over and over by researchers who have come up with increasingly elaborate explanations for it. Psychologists have suggested we hone our skills of rationalization in order to impress others, reaffirm our “moral integrity” and protect our “self-concept” and feeling of “global self-worth.” If so, capuchin monkeys are a lot more complicated than we thought. Or, we’re less complicated. In a paper in Psychological Science, researchers at Yale report finding the first evidence of cognitive dissonance in monkeys and in a group in some ways even less sophisticated, 4-year-old humans. The Yale experiment was a variation of the classic one that first demonstrated cognitive dissonance, a term coined by the social psychologist Leon Festinger. In 1956 one of his students, Jack Brehm, carted some of his own wedding gifts into the lab (it was a low-budget experiment) and asked people to rate the desirability of things like an electric sandwich press, a desk lamp, a stopwatch and a transistor radio. Copyright 2007 The New York Times Company

Keyword: Attention; Emotions
Link ID: 10936 - Posted: 06.24.2010

High blood pressure may be more difficult to control in winter, US research suggests. A five-year study found people treated in the summer were on average 8% more likely to see their blood pressure come down to healthy levels. The US Department of Veterans Affairs team analysed data on 443,632 veterans treated for hypertension. The study, reported to the American Heart Association, suggests a more active summer lifestyle may be the key. Lead researcher Dr Ross Fletcher said: "People gain weight in the winter and lose weight in the summer. People tend to exercise more in the summer and less in the winter." The researchers said it was also possible that people might eat more salty foods in winter. Salt is strongly linked to raised blood pressure. The study analysed electronic health records from 15 VA hospitals in cities throughout the US. People with a blood pressure reading of more than 140 mm Hg systolic or more than 90 mm Hg diastolic on three separate days were identified as hypertensive. The researchers found the same pattern emerged from each hospital they studied, regardless of whether it was based in a warm or cold climate. Locations ranged from Anchorage, Alaska to San Juan, Puerto Rico. Dr Fletcher, chief of staff at the VA Medical Center in Washington, said people should be aware of the possibility their blood pressure may be harder to control in the winter - and be more vigilant at this time. Professor Bryan Williams, a trustee of the Blood Pressure Association, said blood pressure was very variable - even on a minute by minute basis. However, he said blood pressure levels - and rates of stroke and heart attack - tended to be higher in winter. (C)BBC

Keyword: Biological Rhythms
Link ID: 10935 - Posted: 11.06.2007

By Christopher Lane If anyone in my parents' generation had argued that shyness and other run-of-the-mill behaviors might one day be called mental disorders, most people would probably have laughed or stared in disbelief. At the time, wallflowers were often admired as modest and geeks considered bookish. Those who were shy might sometimes have been thought awkward -- my musically gifted mother certainly was -- but their reticence fell within the range of normal behavior. When their discomfort was pronounced, the American Psychiatric Association called it "anxiety neurosis," a psychoanalytic term that encouraged talk-related treatment. All that changed in February 1980, when the APA classified the broadly defined "avoidant personality disorder" and "social phobia" (later dubbed "social anxiety disorder") as diseases. The professional group also listed 110 other new disorders in its revised diagnostic manual, with the result that the total number of mental illnesses on the books almost doubled overnight. It was a dramatic example of the modern medicalization of behavior. Bashfulness, once prized as a virtue, became a sign for medical concern. According to the 1994 National Comorbidity Survey, as much as 12.1 percent of the U.S. population might have social anxiety disorder and a staggering 28.8 percent suffer from some kind of anxiety disorder. © Copyright 1996-20072007 The Washington Post Company

Keyword: Autism; Depression
Link ID: 10934 - Posted: 06.24.2010

By BENEDICT CAREY For an organ that has been scanned millions of times by experts using high-end imaging technology, the brain remains in large part a shrouded landscape, as lost in darkness as the ocean floor. One reason has less to with the brain’s complexity than its uniformity: it contains billions of identical-looking cells, most sprouting multiple identical-looking branches to other cells, near and far. A needle in a haystack at least looks different from the strands around it; finding and mapping large numbers of neurons is more like working out the root system beneath a tropical rain forest. But last week, researchers at Harvard published pictures in which all those anonymous gray cells glowed in distinctive colors, like a bougainvillea bush gone haywire. The scientists bred mice so their brain cells had genetic inserts containing genes for three colors of fluorescent protein, red, green and blue. They prompted each insert to randomly express one color, using a genetic trigger. Because there were multiple copies of the three-gene insert in each cell, the cell itself expressed a random mixture of the three colors, some 90 shades in all. What emerged was a kind of beaded rainbow belt of neurons, with the fluorescent glow radiating out through each cell’s neural branches. The researchers called the technique “Brainbow.” Copyright 2007 The New York Times Company

Keyword: Development of the Brain
Link ID: 10933 - Posted: 06.24.2010

by Jonah Lehrer In 1974 Oliver Sacks was climbing a mountain in Norway by himself. It was early afternoon, and he had just begun his descent when a slight misstep sent him careening over a rocky cliff. His left leg was "twisted grotesquely" beneath his body, his limp knee wracked with pain. "My knee could not support any weight at all, but just buckled beneath me," he wrote in A Leg to Stand On. Sacks began to "row" himself down the mountain, sliding on his back and pushing with his hands, so that his leg, which he'd splinted with his umbrella, was "hanging nervelessly" in front of him. After a few hours, Sacks was exhausted, but he knew that if he stopped he would not survive the cold night. What kept Sacks going was music. As he painstakingly descended the mountain, he began to make a melody out of his movements. "I fell into a rhythm," Sacks writes, "guided by a sort of marching or rowing song, sometimes the Volga Boatman's Song, sometimes a monotonous chant of my own. I found myself perfectly coordinated by this rhythm—or perhaps subordinated would be a better term: The musical beat was generated within me, and all my muscles responded obediently...I was musicked along." Sacks reached the village at the bottom of the mountain just before nightfall. A long convalescence followed, as he tried to regain the use of his injured leg, but the nerves in his limb had been severely damaged. When Sacks tried to walk, he was forced to consciously calculate his movements, to think before each step. © Copyright 2005-2007 Seed Media Group, LLC.

Keyword: Hearing
Link ID: 10932 - Posted: 06.24.2010

By Greg Miller SAN DIEGO, CALIFORNIA--Paris Hilton: Actress, author, ... analgesic? Neuroscientists have found that a cardboard cutout of the ubiquitous Hilton Hotel heiress has a painkilling effect on mice. But don't expect clinical trials to begin anytime soon: Paris works only for males, and it may be only because she stresses them out. The idea for the unconventional experiment arose when Jeffrey Mogil of McGill University in Montreal, Canada, and his colleagues noticed that male mice spent less time licking the site of a painful injection--indicating that they had less pain--when a scientist was present. To investigate whether it was the sight or smell of a human that caused the effect, the researchers acquired a promotional cardboard cutout of Hilton from her television show The Simple Life ("A special order," says Mogil's collaborator Leigh MacIntyre). As in humans, Paris's effect appears to be gender-specific. Male mice spent less time licking their wounds when fake Paris was in sight, but females showed no such effect, the researchers reported here Saturday at the annual meeting of the Society for Neuroscience. When the team put up a screen to block the rodents' view, the effect went away. Following a Paris Hilton encounter, male mice--but not females--also had lower-than-usual expression of a gene called c-fos in a part of the spinal cord that transmits pain signals to the brain, suggesting reduced neural activity in this pain pathway. © 2007 American Association for the Advancement of Science.

Keyword: Pain & Touch; Stress
Link ID: 10931 - Posted: 06.24.2010