By Michael C. Purdy A group of steroids found in female mouse urine goes straight to the male mouse's head, according to School of Medicine researchers. They found the compounds activate nerve cells in the male mouse's nose with unprecedented effectiveness. Timothy Holy "These particular steroids, known as glucocorticoids (GCCs), are involved in energy metabolism, stress and immune function," said senior author Timothy E. Holy, Ph.D., assistant professor of anatomy and neurobiology. "They control many important aspects of the mouse's physiology and theoretically could give any mouse that sniffs them a detailed insider's view of the health of the animal they came from." Holy plans further research to see if activating the nerves in the male mouse's nose leads to particular behavioral responses. He probes the male mouse's reaction to chemical signals from female mice to advance understanding of pattern recognition and learning in the much more complex human brain. In 2005, he found that female mice or their odors cause male mice to sing. Science has long recognized that urine, sweat and other bodily fluids contain chemical communication signals called pheromones that can influence the biology or behavior of others. Most mammals use the information in these signals for social purposes, such as establishing territory or dominance or in courtship and mating. In many cases, though, the specific chemical identities of the signals are unknown.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 11831 - Posted: 07.19.2008

LONDON - Scientists have identified the brain circuits that play a key role in helping us pay attention, a finding that may help explain why things go wrong in diseases such as Alzheimer’s and attention deficit disorders. The finding published in the journal Nature could provide a new target for potential drugs to treat some neurodegenerative conditions and attention deficit hyperactivity disorder or ADHD, the researchers said. “What we have identified is the way this works in one particular area of the brain,” said Alex Thiele, a neuroscientist at Newcastle University, who led the study. “If we ever want to have a smart drug for diseases like Alzheimer’s, we need to understand this level of detail.” Alzheimer’s is a degenerative condition for which there is no cure. An estimated 24 million people worldwide suffer from the memory loss and problems with orientation that signal Alzheimer’s and other, less common forms of dementia. Existing drugs such as Aricept from Pfizer and Eisai, Exelon by Novartis and Razadyne or Reminyl from Johnson & Johnson and Shire can ease symptoms but do not stop the disease. Copyright 2008 Reuters

Keyword: ADHD; Attention
Link ID: 11830 - Posted: 06.24.2010

By Rachel Ehrenberg Researchers look to the good version of the protein implicated in mad cow disease for insight into the protein’s bad side. When the nefarious Mr. Hyde takes his own life, the good Dr. Jekyll is also killed. Scientists are adopting the reverse approach for halting the protein behind prion diseases such as Creutzfeldt-Jakob and mad cow. By targeting the harmless version of the brain protein whose evil alter ego brings on disease, researchers have prevented the bad version of the protein from continuing its rampage in the brains of infected mice. The results are reported online July 14 in Proceedings of the National Academy of Sciences. The approach of killing Jekyll to get Hyde is very promising, comments biochemist Sina Ghaemmaghami of the Institute for Neurodegenerative Diseases at the University of California, San Francisco. The sinister version of the protein comes in several slightly different forms, making it hard to develop a single attack strategy, Ghaemmaghami says. Led by neuroscientist Giovanna Mallucci of University College London, researchers delivered bits of attack RNA to interfere with production of the normal version of the prion protein. In animals who have prion disease, this protein somehow gets converted into a dangerous form, which then travels through the brain, coaxing other good versions of the protein to go bad. © Society for Science & the Public 2000 - 2008

Keyword: Prions
Link ID: 11829 - Posted: 06.24.2010

To say that kids are growing up faster than ever these days may be more than just cliché. Recent studies have shown that children are reaching puberty at younger and younger ages, and researchers are starting to see links between this trend and other societal ills such as ubiquitous pollution and sedentary lifestyles. In a 2007 report for the Breast Cancer Fund entitled “The Falling Age of Puberty in U.S. Girls: What We Know, What We Need to Know,” ecologist Sandra Steingraber argues that unfettered access to computers and TVs over the last 30 years has led to an increasingly sedentary lifestyle among kids in the U.S. and beyond. Active kids produce more melatonin, a natural hormone that serves as the body’s internal clock and calendar. This could explain why sedentary kids are likely to go through puberty sooner: Their bodies think their decreased melatonin production is a trigger to move into puberty. “[Melatonin is] an inhibitory signal for puberty,” says Steingraber. “The more melatonin you have, the later you go into puberty.” Of course, sedentary lifestyles are also linked to childhood obesity, a condition that often continues—along with the many health problems that can accompany it—into adulthood. A recent National Health and Nutrition Examination Survey (NHANES) found that, between 2001 and 2004, 17.5 percent of children ages six to 11 were overweight—an effective doubling of obesity rates three decades ago. A study by the non-profit Obesity Society came up with a slightly higher figure—20 percent—with the percentages higher for Hispanic, African-American and Native American children. © 1996-2008 Scientific American Inc.

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 11828 - Posted: 06.24.2010

When she's dancing the samba, Pat Prescott is all smiles. But her frustration shows when she talks about her daily battle with type 2 diabetes. A typical day for the academic research librarian is filled with one challenge after another revolving around her disease. Here's her description of what she calls, "a good day for me." "I should have already, the day before, the night before, done grocery shopping. And obviously gone to the pharmacy whenever necessary. I should get up in the morning and cook vegetables and the proper protein and have the proper food available for that day, and plan out the whole day. When I leave the house in the morning, I'm gone for 14 to16 hours, so that means that all my medicines for the entire day have to be with me, and they have to be refrigerated or they have to be kept cold. That goes for things like needles and my glucometer and the test strips. And then I should be trying to figure out how to get at least 30 minutes of vigorous exercise in that day." "But that's a good day," she says. "That's a day when I haven't broken down and eaten like a one-by-one-inch sliver of cake at somebody's birthday party, or I haven't eaten a mango or some kind of fruit that really messes up my sugar. But if you can imagine doing that every single day and having that regimen every single day, it's very tiring. You get used to it, but people around you don't get used to it, and if you travel, or if you're invited to someone's house, it's a major undertaking. Traveling is terrible. You just have to prepare for so many eventualities." © ScienCentral, 2000-2008.

Keyword: Obesity
Link ID: 11827 - Posted: 06.24.2010

Linda Geddes It's not just autistic children who view the world differently from the rest of us – it seems their parents may do so as well. Some parents of autistic children evaluate facial expressions in a strikingly similar way to people with the disorder, even though they would not be classified as autistic themselves. The finding strengthens the link between genetics and autism, and may help pinpoint the genes responsible for some of the behavioural traits associated it. Ralph Adolphs of the California Institute of Technology in Pasadena and his colleagues performed psychological tests on 42 parents of autistic children. Based on these tests, they categorised 15 of the parents as being "socially aloof", meaning that they tend not to enjoy small talk for the sake of it, and have very few close friendships involving sharing and mutual support. Both these groups of parents and the parents of 20 non-autistic "neurotypical" children were then asked to look at a series of faces and judge whether they looked happy or fearful. © Copyright Reed Business Information Ltd.

Keyword: Autism
Link ID: 11826 - Posted: 06.24.2010

By Greg Miller Hawks are famous for their sharp vision, and owls are renowned for their keen hearing, but birds rarely get much credit for their sense of smell. That may change thanks to the first analysis of olfactory genes in a wide range of avian species. Birds, it turns out, may be better smellers than we thought. Researchers interested in bird behavior have tended to focus on their flashy mating displays, melodious songs, and other talents, leaving the avian sense of smell largely unexplored. A handful of studies have hinted that smell does play a role in bird behavior (ScienceNOW, 29 October 2004), but very little is known about the underlying biology. In the new study, a team led by molecular ecologist Silke Steiger and her graduate adviser Bart Kempenaers at the Max Planck Institute for Ornithology in Starnberg, Germany, searched for smell-related genes in nine species representing seven major branches of the avian family tree. They looked for genes that encode olfactory receptors, which detect odors. Researchers generally assume that animals with a greater variety of receptors have a better sense of smell. Mice, for example, have close to 1000 working olfactory receptor genes, and humans have roughly 400. By this logic, the most acute sense of smell in Steiger's menagerie belongs to the kakapo, a rare nocturnal parrot indigenous to New Zealand. The team estimates that the kakapo has 667 functional olfactory receptor genes. © 2008 American Association for the Advancement of Science

Keyword: Chemical Senses (Smell & Taste); Evolution
Link ID: 11825 - Posted: 06.24.2010

Exercise may slow the atrophy of the brain brought on by Alzheimer's, suggests a new study. Researchers at the University of Kansas School of Medicine found that study participants who had mild Alzheimer's and who worked out regularly had larger brains that those who did not exercise regularly. They studied 121 people 60 and over, exposing them to fitness tests while measuring their white and grey brain matter and overall brain volume using MRI. Fifty-seven of the participants had early-stage Alzheimer's while the rest of the participants did not have dementia. "People with early Alzheimer's disease who were less physically fit had four times more brain shrinkage when compared to normal older adults than those who were more physically fit, suggesting less brain shrinkage related to the Alzheimer's disease process in those with higher fitness levels," said study author Jeffrey Burns, of the University of Kansas School of Medicine in Kansas City, in a release. A decreasing brain volume has been linked in previous research to poorer cognitive performance. Conversely, exercise has the opposite effect. "Higher fitness through increased physical activity has been associated with enhanced neuronal survival to brain insults, increased vascularization, and elevations of growth factors in areas important for memory," reads the study. © CBC 2008

Keyword: Alzheimers
Link ID: 11824 - Posted: 06.24.2010

By Adam Hadhazy A brain chemical linked to pleasure and depression may also trigger fear, according to a new study. Researchers say this may explain why the neurotransmitter dopamine, known to cause addictive behavior, may also play a role in anxiety disorders. "Showing that dopamine can enhance both approach and avoidance behaviors is an important finding," says Howard Fields, a neurobiologist at the University of California, San Francisco. Approach behavior describes what someone attracted to an object does to obtain it. Fields says the finding reveals a new potential target for treating puzzling neurological disorders such as schizophrenia. Scientists have long suspected that dopamine was linked to dread as well as delight. To confirm their suspicions, University of Michigan at Ann Arbor researchers studied what happens to rats when the neurotransmitter is blocked from reaching the rear portion of the nucleus accumbens, a brain region where dopamine is produced and reward-seeking activities (such as eating and other urges) as well as emotions including fear are processed. Their findings, published in the Journal of Neurology: the animals remained calm even when scientists also removed a fear-controlling brain chemical (glutamate), which ordinarily would have sent them into a tizzy. This suggests that too much dopamine in the rear of the nucleus accumbens (linked to dread) may at least be partly responsible for the paranoia that many schizophrenia patients experience, study co-author Kent Berridge says. © 1996-2008 Scientific American Inc.

Keyword: Drug Abuse; Emotions
Link ID: 11823 - Posted: 06.24.2010

By Mauricio Delgado The development of trust is an essential social tool, allowing people to form productive and meaningful relationships, both at a professional and personal level. Bonds of trust are also extremely fragile, however and a single act of betrayal—such as a marital affair—can instantly erase years of trustworthy behavior. The consequences of such breaches in confidence can be disastrous, and not only for a relationship. People who have been betrayed in the past will sometimes start avoiding future social interactions, which is a potential precursor to social phobia. In light of these connections, recent research has attempted to elucidate the neural mechanisms underlying trust behavior. This is the goal of an exciting new study by neuroscientist Thomas Baumgartner and colleagues at the University of Zurich in Germany that combines different disciplines (economics and neuroscience) and methodologies (neuroimaging and neuropharmacology) to investigate how the brain adapts to breaches of trust. To study social interactions, economists, and more recently neuroscientists, take advantage of a simple game played between two people called the “trust game.” (For more on greed and altruism, see this.) In a typical trust game, an investor (Player 1) is faced with a decision to keep a sum of money (say, $10) or share it with a trustee (Player 2). If shared, the investment is tripled ($30) and the trustee now faces the decision to repay the trust by sending back a larger amount of the initial investment (for example, $15 for each participant) or to defect and violate trust by keeping the money. In this game, the investor is therefore left with an important social dilemma: to trust or not to trust. Although it is more profitable to trust, doing so leaves the investor at risk of betrayal. © 1996-2008 Scientific American Inc.

Keyword: Hormones & Behavior; Emotions
Link ID: 11822 - Posted: 06.24.2010

Kerri Smith Sleepless nights can increase your chances of forming false memories, according to researchers in Germany and Switzerland. But, as for so many aspects of life, it seems that coffee can save the day. Although neuroscientists know that memories can be strengthened while we are asleep, it's been unclear whether false memories form as we slumber or whether they are only consolidated when we are asked to recall the information the following morning. To find out, Susanne Diekelmann in Jan Born's lab at the University of Lübeck, Germany, and her colleagues asked volunteers to learn lists of words, each list relating to a particular topic. For example, they might learn the words 'white', 'dark', 'cat' and 'night' — all of which can be linked to the word 'black' — but black itself would not be part of the list. The researchers then tested their subjects' memories after a night's sleep or a night spent awake. They showed them the list of words again, having added a few extra words, and asked them to recall whether the words had been in the original list. The sleep-deprived group gave more false responses than the group allowed to sleep. "A lot of subjects said, 'yes, these false words were presented before', and they were absolutely sure about it," says Diekelmann. "Sometimes they were even more convinced than on the real words." © 2008 Nature Publishing Group

Keyword: Sleep; Learning & Memory
Link ID: 11821 - Posted: 06.24.2010

Meredith Wadman Some parents blame their children’s autism on mercury in vaccines.R. Faris/CorbisThe leading US government funder of autism research is drawing fire over its proposal to run a randomized clinical trial of a treatment widely viewed by experts to be useless and potentially harmful, but that is broadly used for autism. Chelation therapy, in which agents such as dimercaptosuccinic acid (DMSA) are used to bind metal ions in the blood so that they can be excreted easily, is an approved treatment for heavy-metal poisoning. Parents are using such therapy on children with autism because of their belief — which has been scientifically discredited — that mercury from vaccinations caused their children’s condition. In May, investigators at the US National Institute of Mental Health (NIMH) in Bethesda, Maryland, won approval from the US Food and Drug Administration to use DMSA in a trial of children with autism who are aged four to ten years and have detectable, but not toxic, levels of mercury or lead in their blood. The trial, ‘Mercury Chelation to Treat Autism’, is now under ethics review and has not enrolled any patients. Critics say the trial will put children at risk for what is certain to be no medical gain. The American Academy of Pediatrics has concluded that there is no justification for giving children DMSA in the absence of very high levels of heavy-metal exposure, notes epidemiologist Ellen Silbergeld of the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland. “I don’t know why we have to do this experiment again on children.”

Keyword: Autism; Neurotoxins
Link ID: 11820 - Posted: 06.24.2010

By Robin Nixon Contrary to the moans of many dieters, being hungry may make you happy. Or, at least, it can be a serious motivator whose evolutionary intent was to help you find dinner instead of becoming dinner. When our bodies notice we need more calories, levels of a hormone called ghrelin increase. Ghrelin is known to spur hunger, but new research suggests this may be a side effect of its primary job as a stress-buster. Researchers manipulated ghrelin levels in mice through a variety of methods, including prolonged calorie restriction, ghrelin injection and a genetic modification rendering the mice numb to ghrelin’s effect. Mice who had limited ghrelin activity seemed depressed. If pushed into deep water they made no effort to swim. When introduced to a maze, they clung to the entryway. And when placed with other mice, they tended to keep to themselves. (These behaviors were reversed when the mice were given a low-dose antidepressant commonly prescribed to humans.) In contrast, mice with high levels of ghrelin swam energetically in deep water, looking for escape. They eagerly explored new environments. And they were much more social. © 2008 LiveScience.com.

Keyword: Obesity; Emotions
Link ID: 11819 - Posted: 06.24.2010

Nicotine-based drugs may help delay the moment a person with dementia has to enter a care home, say researchers. Nicotine has toxic effects, and carries a strong risk of addiction, but scientists have shown it can also boost learning, memory and attention. The effect is small, but it may help give dementia patients up to six extra months of independent living. A team at King's College London have demonstrated the positive effects of nicotine in experiments on rats. They showed that nicotine boosted the animals' ability to carry out a task accurately - particularly when they were also distracted. When able to give full concentration, the animals responded correctly to stimuli about 80% of the time. Nicotine boosted the accuracy rate by about 5%. However, when distracted, the animals' success rate fell to about 55%. In this case nicotine brought it back up to around the 85% level. The King's team, based at the Institute of Psychiatry, studied the mechanisms which underpin the effects produced by nicotine. They showed how proteins on the surface of cells respond to the compound, and pinned down the role of several key chemicals in the brain, including dopamine and noradrenaline. It transpired that there are only subtle biochemical differences in the way nicotine stimulates the brain, and triggers addiction. Key is the fact that nicotine stimulates flow of the hormone adrenaline in the body, which can produce both effects. (C)BBC

Keyword: Alzheimers; Drug Abuse
Link ID: 11818 - Posted: 07.14.2008

By DONALD G. McNEIL Jr. If you caught your son burning ants with a magnifying glass, would it bother you less than if you found him torturing a mouse with a soldering iron? How about a snake? How about his sister? Such apparently unrelated questions arise in the aftermath of the vote of the environment committee of the Spanish Parliament last month to grant limited rights to our closest biological relatives, the great apes — chimpanzees, bonobos, gorillas and orangutans. The committee would bind Spain to the principles of the Great Ape Project, which points to apes’ human qualities, including the ability to feel fear and happiness, create tools, use languages, remember the past and plan the future. The project’s directors, Peter Singer, the Princeton ethicist, and Paola Cavalieri, an Italian philosopher, regard apes as part of a “community of equals” with humans. If the bill passes — the news agency Reuters predicts it will — it would become illegal in Spain to kill apes except in self-defense. Torture, including in medical experiments, and arbitrary imprisonment, including for circuses or films, would be forbidden. The 300 apes in Spanish zoos would not be freed, but better conditions would be mandated. Copyright 2008 The New York Times Company

Keyword: Animal Rights
Link ID: 11817 - Posted: 06.24.2010

Sleep appears to strengthen connections between communicating nerve cells in the brain - a process thought to form the basis of learning and memory. Scientists in Switzerland studied a group of volunteers who were taught a new skill or shown images they would later have to remember. The skill tasks included trying to follow a moving dot on a computer screen using a joy stick. One group of participants was then allowed to sleep normally for eight hours, while others were deprived of sleep or only permitted a nap. The next day they were asked to repeat the tasks or recall the images while their brains were scanned using a technique known as functional magnetic resonance imaging (fMRI). Those who had slept properly performed better, and this was reflected in their brain activity. Dr Sophie Schwartz, from the University of Geneva, who led the study, said: "Our results revealed that a period of sleep following a new experience can consolidate and improve subsequent effects of learning from the experience. "This improvement comes from changes in brain activity in specific regions that code for relevant features of the learned material." © Copyright of Telegraph Media Group Limited 2008

Keyword: Sleep
Link ID: 11816 - Posted: 06.24.2010

Brain ventricles that increase in size could be a sign of cognitive problems and the onset of Alzheimer's disease, say Canadian researchers. Researchers at the University of Western Ontario used magnetic resonance imaging to examine the brains of 504 people across North America who had enrolled in the Alzheimer's disease neuroimaging initiative — at the onset of the study and six months later. They found that when ventricles enlarge, the surrounding brain tissue dies. The increase in size occurs during mild cognitive impairment and continues to do so as Alzheimer's sets in and progresses. Ventricles are one of a system of four communicating cavities within the brain and are filled with cerebrospinal fluid. The study also found that patients who had Alzheimer's at the beginning of the study had 60 per cent more rapid expansion of ventricles compared to people with mild cognitive impairment. "These findings mean that, in the future, by using magnetic resonance imaging [MRI] to measure changes in brain ventricle size, we may be able to provide earlier and more definitive diagnosis," said Robert Bartha, lead author of the study, in a release. "In addition, as new treatments for Alzheimer's are developed, the measurement of brain ventricle changes can also be used to quickly determine the effectiveness of the treatment." sticky coverings that form outside neurons, are usually discovered during an autopsy. © CBC 2008

Keyword: Alzheimers; Brain imaging
Link ID: 11815 - Posted: 06.24.2010

By BENEDICT CAREY The study of anxiety is fast merging with the science of memory. No longer focused just on symptoms like social isolation and depressed mood, scientists are turning to the disorder’s neural roots, to how the brain records and consolidates in memory the frightening events that set off long-term anxiety. And they are finding that it may be possible to blunt the emotional impact of even the worst memories and fears. The war in Iraq has lent a new cultural urgency to this research. About one in eight of the troops returning from combat show signs of post-traumatic stress disorder, or P.T.S.D., which is characterized by intrusive thoughts, sleep loss and hyper-alertness following a horrifying experience. Many are so traumatized that they fail utterly to respond to antianxiety medications, talk therapy and other conventional treatments. P.T.S.D. is one of the most worrisome of the generally recognized anxiety disorders. There are four others: generalized anxiety disorder (G.A.D.), obsessive-compulsive disorder, phobias and panic disorder. G.A.D. is the most common, but all are familiar complaints in doctors’ offices: more than 20 million Americans will suffer one of these during his or her lifetime. Genetics and the environment play roles in the development of anxiety disorders, but the point where these influences intersect is clearly the brain. The biology of anxiety has been very difficult to untangle in part because it is so familiar, so integral to our survival. Copyright 2008 The New York Times Company

Keyword: Stress; Emotions
Link ID: 11814 - Posted: 06.24.2010

By David Brown New research suggests that some cases of autism arise from defects in genes that can be turned on or off by mental activity, a finding that sheds light on the devastating condition and might eventually lead to strategies to treat it. The findings are drawn from gene scans of about 100 Middle Eastern families in which autism is unusually common. The disorder is marked by social isolation, speech problems and strange, repetitive activities. The study, done by a large international team and reported today in the journal Science, adds to the growing evidence that autism may result from problems in the immensely complicated process by which some networks of brain cells expand and many others die in the first few years after birth. The fact that three of the half-dozen genes identified in the new report are regulated by "neuronal activity" -- feeling, thinking, doing -- suggests in theory that changing the experiences of autistic children could change the course of the disease. "The genes implicated in our study are ones that interact with the environment and are involved in how the brain converts what it sees from the environment," said Christopher A. Walsh, a neurologist and chief of genetics at Children's Hospital in Boston who headed the team. "If we can activate those genes by other mechanisms, we might be able to help the kids." © 2008 The Washington Post Company

Keyword: Autism; Genes & Behavior
Link ID: 11813 - Posted: 06.24.2010

By Emily V. Driscoll Two penguins native to Antarctica met one spring day in 1998 in a tank at the Central Park Zoo in midtown Manhattan. They perched atop stones and took turns diving in and out of the clear water below. They entwined necks, called to each other and mated. They then built a nest together to prepare for an egg. But no egg was forthcoming: Roy and Silo were both male. Robert Gramzay, a keeper at the zoo, watched the chinstrap penguin pair roll a rock into their nest and sit on it, according to newspaper reports. Gramzay found an egg from another pair of penguins that was having difficulty hatching it and slipped it into Roy and Silo’s nest. Roy and Silo took turns warming the egg with their blubbery underbellies until, after 34 days, a female chick pecked her way into the world. Roy and Silo kept the gray, fuzzy chick warm and regurgitated food into her tiny black beak. Like most animal species, penguins tend to pair with the opposite sex, for the obvious reason. But researchers are finding that same-sex couplings are surprisingly widespread in the animal kingdom. Roy and Silo belong to one of as many as 1,500 species of wild and captive animals that have been observed engaging in homosexual activity. Researchers have seen such same-sex goings-on in both male and female, old and young, and social and solitary creatures and on branches of the evolutionary tree ranging from insects to mammals. © 1996-2008 Scientific American Inc.

Keyword: Sexual Behavior
Link ID: 11812 - Posted: 06.24.2010