Heidi Ledford Those who have been keeping a mental tally of the differences between males and females can now add another 25,281 items to the list. That's the number of differences that researchers have found in gene expression between male and female mice, according to a report published online in this month's Genome Research1. With the exception of sex chromosomes, males and females have all the same genes; although variations in these genes and the genetic material between them produce the different types and amounts of proteins that make one person different from another. Researchers have found that other factors, such as sex hormones, can also affect the amount of protein produced, making gene expression broadly different in males and females. That in turn could affect, for example, the way that drugs are metabolized by men versus women. A few thousand such differences have been identified before. But now researchers have taken a huge step up in cataloguing the number of genes that behave differently from one sex to the next. "The results have particular importance for understanding common diseases, almost all of which exhibit some sex bias," says Jake Lusis, a geneticist at the University of California, Los Angeles, and co-author of the study. "For example, women are much more susceptible to most autoimmune diseases, such as lupus and multiple sclerosis, whereas men are more susceptible to heart disease and Alzheimer's disease." ©2006 Nature Publishing Group

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 9106 - Posted: 06.24.2010

Bruce Bower Although hyperactive behavior often abates during the teen years for girls with attention-deficit hyperactivity disorder, many struggle with serious academic, emotional, and social problems related to that condition, a 5-year study finds. Compared with teenage girls who had no psychiatric disorder, those with ADHD had difficulties that included delinquency, depression, substance abuse, eating disorders, poor mathematics and reading achievement, rejection by peers, and lack of planning skills, reports a team led by psychologist Stephen P. Hinshaw of the University of California, Berkeley. "ADHD in girls is likely to yield continuing problems in adolescence, even though hyperactive symptoms may recede," Hinshaw says. The new findings appear in the June Journal of Consulting and Clinical Psychology. In 1997, Hinshaw's team organized the first of three yearly summer camps for 6- to 12-year-old girls, including individuals already diagnosed with ADHD. The project focused on 140 girls with ADHD and 88 girls with no psychiatric disorder, all of whom completed one of the 5-week programs. Staff monitored each girl's daily behavior and administered a battery of tests without knowing who had an ADHD diagnosis. ©2006 Science Service

Keyword: ADHD; Sexual Behavior
Link ID: 9105 - Posted: 06.24.2010

WASHINGTON -- Better pay attention, reader. This whole story may be a blur. For the first time, researchers have demonstrated the ill effects of mindless reading - a phenomenon in which people take in sentence after sentence without really paying attention. Ever read the same paragraph three times? Or get to the end of a page and realize you don't know what you just read? That's mindless reading. It is the literary equivalent of driving for miles without remembering how you got there - something so common many people don't even notice it. In a new study of college students, researchers from the University of Pittsburgh and the University of British Columbia established a way to study mindless reading in a lab. Their findings showed that daydreaming has its costs. The readers who zoned out most tended to do the worst on tests of reading comprehension - a significant, if not surprising, result. The study also suggested that zoning out caused the poor test results, as opposed to other possible factors, such as the complexity of the text or the task. © 2002-2006 redOrbit.com.

Keyword: Attention; Language
Link ID: 9104 - Posted: 06.24.2010

"Brainy kids aren't brainy just because they have more grey matter," says brain researcher Philip Shaw, of the National Institute of Mental Health (NIMH), referring to the kinds of cells that make up part of the brain. "I think that's part of the story, but not all of it. Rather, intelligence is related to the dynamics of how the brain grows." Shaw and his research team found that children who scored highest on IQ tests had a distinctive pattern of brain growth. They used MRI brain scans to follow the development of the brains of 307 children from age seven to their late teens. While they found no difference in the kids' brain size by late adolescence, those with the highest IQ scores actually started out with a thinner than average cortex -- the outer layer of the brain that helps us reason and make decisions. "The really highly intelligent children, they started off with a very thin cortex, it got thicker very quickly, peaked, and then also got thinner very quickly," Shaw explains. "Average intelligence children showed the same sort of pattern, but all the changes happen much more slowly. There was a very slow increase and a very slow decrease, and they also reached their peak cortical thickness a couple of years before the very intelligent children." © ScienCentral, 2000-2006.

Keyword: Intelligence; Development of the Brain
Link ID: 9103 - Posted: 06.24.2010

By Greg Miller Alzheimer's disease, a dreaded specter for many elderly, is far more likely to strike individuals with Down syndrome. Now, a study with a mouse model of Down syndrome may explain why. The work hints at potential targets for future drugs that fend off dementia--in people with Down syndrome and in the general population too. Down syndrome is caused by an extra copy of chromosome 21. It affects roughly 1 in 800 people, causing mild to moderate mental retardation and a range of other health problems, including early-onset dementia. By age 40, the brains of all people with Down syndrome develop the hallmark plaques and tangles of Alzheimer's and other signs of brain atrophy, autopsy studies have found. No one knows why this happens, but many researchers suspect this neurodegeneration has something to do with a gene called App. People with Down syndrome have an extra copy of this gene, which contributes to plaque formation in the brains of Alzheimer's patients. (The gene's normal function isn't clear). The new research begins to explain why the extra copy of App kills neurons. A team led by Ahmad Salehi and William Mobley at Stanford University in California examined mice with extra copies of many of the genes found on human chromosome 21. As these mice age, a certain group of neurons deep in their brains dies off, and they experience cognitive declines. These neurons, which use the neurotransmitter acetylcholine, also die in Alzheimer's patients. © 2006 American Association for the Advancement of Science.

Keyword: Alzheimers; Development of the Brain
Link ID: 9102 - Posted: 06.24.2010

Jennifer Viegas, Discovery News — A baboon hand gesture appears to send the message "go ahead, make my day" to other baboons — suggesting that gesturing may have been a precursor to human language, according to a new study. The findings could help to explain why humans often gesture with their hands, and particularly the right hand, when they speak. Since the right hand is controlled by the brain’s left hemisphere, which is the source of most linguistic functions, scientists believe communication by hand likely existed in apes 30 million years ago and was a forerunner to spoken and written language among people. Researchers Adrien Meguerditchian and Jacques Vauclair studied a particular hand gesture in 60 captive baboons. The gesture consists of quick and repetitive rubbing or slapping of the hand on the ground, and is used to threaten or intimidate others. Meguerditchian and Vauclair, who work in the Research Center of Psychology of Cognition, Language and Emotion at the University of Provence, France, told Discovery News that this motion "might be comparable in humans to the slap of ... one hand toward the palm of the other hand." © 2006 Discovery Communications Inc

Keyword: Language; Evolution
Link ID: 9101 - Posted: 06.24.2010

RICHMOND, Va. – Researchers have found that genetic factors may play an important role in a person’s use, misuse or dependence of illicit drugs like marijuana, stimulants, opiates, cocaine and psychedelics. In the July issue of the journal Psychological Medicine, Virginia Commonwealth University researchers, in collaboration with researchers from Norwegian Institute of Public Health and University of Oslo in Norway, reported the results of a population-based study of twin pairs that showed that genetic factors influence the illicit drug use in Norway, a country with significantly low levels of psychoactive substance use disorder. “Prior twin studies of illicit drug use and abuse have all been conducted in Anglophonic countries, specifically the United States and Australia, with high levels of such use. This is the first study of a non-English speaking country with much lower rates of drug use - yet results are similar - drug use and abuse or dependence is quite heritable,” said lead author Kenneth S. Kendler, M.D., a professor of psychiatry and human genetics in VCU’s School of Medicine. The team examined the role of genetic and environmental factors in the progression of psychoactive substance use and abuse.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 9100 - Posted: 06.24.2010

Michael Hopkin Neuroscientists have found that rats are more likely to get hooked on heroin if they have previously been given cannabis. The studies suggest a biological mechanism — at least in rats — for the much-publicized effect of cannabis as a 'gateway' to harder drugs. The discovery hints that the brain system that produces pleasurable sensations when exposed to heroin may be 'primed' by earlier exposure to cannabis, say researchers at the Karolinska Institute in Stockholm, Sweden, who carried out the study. There has long been a debate about whether exposure to drugs such as nicotine or marijuana might lead to harder habits. Many argue that the most important factors in the equation are social ones: people who get one drug from a dealer are probably more inclined to try another. But researchers are still interested to know whether there is any physiological effect that might additionally predispose users of so-called soft drugs to harder-drug addiction. To rule out social factors, the researchers turned to an animal model. They dosed some rats with the active ingredient of cannabis and others with a neutral compound during their adolescence (when they were about four to six weeks old). After that, they gave the rats intermittent access to heroin for several weeks, obtained by pressing a lever. ©2006 Nature Publishing Group

Keyword: Drug Abuse
Link ID: 9099 - Posted: 06.24.2010

By Jane Elliott Could the humble chilli pepper hold the answer to arthritis pain? Scientists at King's College, London are hoping they can harness the heat in chilli peppers and adapt it to combat inflammation in arthritis. Although the work is still in the very early stages scientists hope their research will lead to a drug being manufactured. Rheumatoid arthritis is an inflammatory disease, in which the body's immune system attacks the joints, leading to pain, inflammation and stiffness. It affects about 600,000 people in the UK. For most of her adult life, Sue Arnott, from the Midlands, has had rheumatoid arthritis and her joints have crumbled. Sue, now aged 54, has had one knee joint replaced twice, the other once, she has had a replacement hip and has needed surgery on a foot and hand. Her hands are very malformed, and she can not stretch out her fingers properly, making opening doors and locks very difficult. Sue explained that her knees had been the worst affected, and that when the cover protecting her joints was destroyed she had been left 'walking with bone against bone, which was excruciating.' Since her joint replacements, Sue has had a respite from her pain, but she knows it could just be a matter of time before other joints are affected again. (C)BBC

Keyword: Pain & Touch
Link ID: 9098 - Posted: 07.05.2006

Children exposed to the pesticide DDT while in the womb experience development problems, researchers say. The pesticide was banned in the US and UK in the 1970s, but it is still used in some countries to kill malaria-carrying mosquitoes. It was already known DDT was linked to premature births and low birthweight. The University of California Berkeley researchers say their findings, published in Pediatrics, should be borne in mind when addressing malaria. DDT, an organochlorine, persists in the environment long after use, accumulating in the food chain and in fatty tissues of animals and humans. Over time, it degrades into DDE and DDD, which have similar chemical and physical properties. Thirty-three years after its use was banned in the US, DDT is still detectable in about five to 10% of people, while DDE is detectable in nearly everyone. The UC Berkeley researchers measured blood levels of DDT and one of its breakdown products, DDE, in 360 pregnant women, the majority of whom were born in Mexico, where agricultural use of the chemical was only banned in 2000. Factors including age, income, education, marital and work status, the child's gender, duration of breastfeeding and the quality of the home environment for young children were considered. (C)BBC

Keyword: Development of the Brain; Neurotoxins
Link ID: 9097 - Posted: 07.05.2006

Hugging a hot-water bottle can have a similar effect to a painkiller by effectively "deactivating" pain at a molecular level, scientists say. Researchers from University College London used DNA technology to monitor heat and pain receptors within cells. They say temperatures over 40C (104F) switch on internal heat receptors which block the effect of chemical messengers that cause the body to detect pain. Their research was presented to the Physiological Society conference. The researchers wanted to look at why heat relieved internal pain such as period cramps and colic. They used DNA technology to make both heat and pain receptor proteins in the same cell and watching the molecular interactions between the heat receptor TRPV1 and the P2X3 pain receptor. The team found that the heat receptor can block the pain receptor. This pain message is activated by ATP when it is released from damaged and dying cells. By blocking the pain receptors, TRPV1 is able to stop the pain being sensed by the body. Dr Brian King, of UCL Department of Physiology, who led the research said the molecular data showed heat could relieve pain for up to an hour. (C) BBC

Keyword: Pain & Touch
Link ID: 9096 - Posted: 07.05.2006

By DAVID TULLER A vaccine for smoking? The idea is not so far-fetched. Researchers at the University of California, San Francisco, and eight other institutions have just started a major study of a vaccine that seeks to block the pleasurable sensations of satisfying a nicotine addiction. The vaccine would stimulate production of antibodies that would latch onto nicotine molecules and prevent them from reaching the brain. The effort to find a nicotine vaccine is part of an emerging wave of research into vaccines against addictive substances. Researchers and pharmaceutical companies are also investigating vaccines that would generate antibodies against cocaine, heroin and methamphetamine. Even if the trial of the nicotine vaccine, called NicVax, proved successful, it would take at least two years before the product reached the market, researchers said. Two other nicotine vaccine candidates are in the pipeline, said Dr. Frank Vocci, director of the National Institute on Drug Abuse's division of pharmacotherapies. But NicVax, made by Nabi Biopharmaceuticals, is further along. Copyright 2006 The New York Times Company

Keyword: Drug Abuse
Link ID: 9095 - Posted: 07.05.2006

BENEDICT CAREY Pets, homeowners and exterminators show little sympathy toward rodents, but that does not mean the little scavengers lack feelings for one another. Last week, scientists studying the experience of pain in mice found strong evidence of empathy in those who saw a fellow creature suffering. In a series of experiments, reported in the journal Science, neuroscientists demonstrated that mice suffered significantly more distress when they saw a familiar mouse suffering than when they saw the same kind of pain in a stranger. Researchers call this shared suffering "emotional contagion" and consider it a primitive and necessary precursor to human empathy. Apes, including orangutans and chimps, show clear understanding for the suffering of others in their clans and act to help them; elephants and dolphins also show some of the same instincts. But the new study is the first clear demonstration of sensations of shared suffering in mice, experts say. "This is a highly significant finding and should open the eyes of people who think empathy is limited to our species," said Frans B. M. de Waal, a primatologist at Emory University and the author of "Our Inner Ape." Copyright 2006 The New York Times Company

Keyword: Pain & Touch; Animal Communication
Link ID: 9094 - Posted: 07.05.2006

James Jean Teenagers have been drinking alcohol for centuries. In pre-Revolutionary America, young apprentices were handed buckets of ale. In the 1890's, at the age of 15, the writer Jack London regularly drank grown sailors under the table. For almost as long, concerned adults have tried to limit teenage alcohol consumption. In the 1830's, temperance societies administered lifelong abstinence pledges to schoolchildren. Today, public health experts regularly warn that teenage drinkers run greatly increased risks of involvement in car accidents, fights and messy scenes in Cancún. But what was once a social and moral debate may soon become a neurobiological one. The costs of early heavy drinking, experts say, appear to extend far beyond the time that drinking takes away from doing homework, dating, acquiring social skills, and the related tasks of growing up. Mounting research suggests that alcohol causes more damage to the developing brains of teenagers than was previously thought, injuring them significantly more than it does adult brains. The findings, though preliminary, have demolished the assumption that people can drink heavily for years before causing themselves significant neurological injury. And the research even suggests that early heavy drinking may undermine the precise neurological capacities needed to protect oneself from alcoholism. Copyright 2006 The New York Times Company

Keyword: Drug Abuse; Development of the Brain
Link ID: 9093 - Posted: 07.05.2006

In preliminary results, researchers have shown that a drug which mimics the effects of the nerve-signaling chemical dopamine causes new neurons to develop in the part of the brain where cells are lost in Parkinson's disease (PD). The drug also led to long-lasting recovery of function in an animal model of PD. The findings may lead to new ways of treating PD and other neurodegenerative diseases. The study was funded in part by the NIH's National Institute of Neurological Disorders and Stroke (NINDS). The study suggests that drugs that affect dopamine D3 receptors might trigger new neurons to grow in humans with the disease. Some of these drugs are commonly used to treat PD. The finding also suggests a way to develop new treatments for PD. The results appear in the July 5, 2006, issue of The Journal of Neuroscience.* Parkinson's disease, a progressive neurodegenerative disorder that causes tremors, stiffness, slow movements, and impaired balance and coordination, results from the loss of dopamine-producing neurons in part of the brain called the substantia nigra. While many drugs are available to treat these symptoms during the early stages of the disease, the treatments become less effective with time. There are no treatments proven to slow or halt the course of PD. However, many researchers have been trying to find ways of replacing the lost neurons. One possible way to do this would be to transplant new neurons that are grown from embryonic stem cells or neural progenitor cells. However, this type of treatment is very difficult for technical reasons.

Keyword: Parkinsons
Link ID: 9092 - Posted: 07.05.2006

Data from a survey of 43,000 U.S. adults heighten concerns that early alcohol use, independent of other risk factors, may contribute to the risk of developing future alcohol problems. Those who began drinking in their early teens were not only at greater risk of developing alcohol dependence at some point in their lives, they were also at greater risk of developing dependence more quickly and at younger ages, and of developing chronic, relapsing dependence. Among all respondents who developed alcoholism at some point, almost half (47 percent) met the diagnostic criteria for alcohol dependence (alcoholism) by age 21. The associations between early drinking and later problems held even after investigators controlled for other risk factors for dependence, adding to concerns that drinking at a young age might raise the risk of future alcohol problems rather than being an identifying feature of young people predisposed to risky behavior. The study appears in the July issue of Archives of Pediatrics & Adolescent Medicine (volume 160, pages 739-746). Elias A. Zerhouni, M.D., director of the NIH, said, “This is a very good example of how insights gained from health research can inform public policy. Converging research suggests that youthful drinking is associated with an increased risk of long-term, not just acute, health consequences.” Scientists at the Boston University School of Public Health and Youth Alcohol Prevention Center, led by Dr. Ralph Hingson*, carried out the analysis using data from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), a representative survey of the U.S. civilian noninstitutionalized population aged 18 years and older.

Keyword: Drug Abuse
Link ID: 9091 - Posted: 06.24.2010

The first gene known to control the internal clock of humans and other mammals works much differently than previously believed, according to a study by Utah and Michigan researchers. The surprising discovery means scientists must change their approach to designing new drugs to treat jet lag, insomnia, some forms of depression, sleep problems in shift workers and other circadian rhythm disorders, according to researchers at the University of Utah's Huntsman Cancer Institute and the University of Michigan, Ann Arbor. The study – which involved the so-called tau mutation that causes hamsters to have a 20-hour day instead of a 24-hour day – will be published online the week of July 3 in the journal Proceedings of the National Academy of Sciences. The researchers discovered that what was previously believed about the tau mutation – that a decrease in gene activity sped up a mammal's internal clock – was incorrect. Instead, the mutation caused an increase in gene activity to speed up the clock, making the day two to four hours shorter for affected animals. Previous work had indicated that the tau mutation occurred in a gene called casein kinase 1 epsilon (CK1) and that the mutation caused an 85 percent loss of gene activity. This, it was thought, explained why the hamster had a short day. But as it turns out, this idea was wrong.

Keyword: Biological Rhythms
Link ID: 9090 - Posted: 06.24.2010

Helen Phillips A study of the "miraculous" recovery of a man who spent 19 years in a minimally conscious state has revealed the likely cause of his regained consciousness. The findings suggest the human brain shows far greater potential for recovery and regeneration then ever suspected. It may also help doctors predict their patients’ chances of improvement. But the studies also highlight gross inadequacies in the system for diagnosing and caring for patients in vegetative or minimally conscious states. In 1984, 19-year-old Terry Wallis was thrown from his pick-up truck during an accident near his home in Massachusetts, US. He was found 24 hours later in a coma with massive brain injuries. Within a few weeks he had stabilised in a minimally conscious state, which his doctors thought would last indefinitely. It did indeed persist for 19 years. Then, in 2003, he started to speak. Over a three day period, Wallis regained the ability to move and communicate, and started getting to know his now 20 year old daughter – a difficult process considering he believed himself to be 19, and that Ronald Reagan was still president. © Copyright Reed Business Information Ltd.

Keyword: Regeneration
Link ID: 9089 - Posted: 06.24.2010

Review by Ben Lovett I began reading The Little Monster after dinner on a recent evening, intending to finish the first few chapters and then turn to other projects, but the book moves so quickly that I couldn't stop reading, and I finished it that night. Robert Jergen is an engaging writer and, as an autobiographer should, he knows his subject very well. When he recounts anecdotes from his childhood revealing the extent of the impairment caused by his ADHD symptoms, and when he writes about how even today, as a university professor, his symptoms get him into trouble, his book makes for fascinating reading. However, readers should be warned that it is not always a reliable source of scientific information about ADHD. Jergen begins with an introductory chapter, "The Power of ADHD," in which he describes general features of the disorder, including the three classes of symptoms (inattention, hyperactivity, and impulsivity). Many of his points about the difficulty of diagnosing ADHD and the high incidence of misdiagnosis will be useful for readers. Unfortunately, he also claims in this chapter that "people with ADHD tend to be very smart or even cognitively gifted." This is a claim that he repeats elsewhere in the book, despite evidence to the contrary; although there are certainly people who have ADHD and a very high IQ, research has consistently shown that the average intelligence level is not higher in individuals with ADHD. Several following chapters focus on Jergen's childhood and adolescence. One important theme in this section is the author's transition from a generally happy child to a frustrated and upset young man. Copyright © CenterSite, LLC, 1995-2006

Keyword: ADHD
Link ID: 9088 - Posted: 06.24.2010

By Michael Shermer The human understanding when it has once adopted an opinion ... draws all things else to support and agree with it. And though there be a greater number and weight of instances to be found on the other side, yet these it either neglects and despises ... in order that by this great and pernicious predetermination the authority of its former conclusions may remain inviolate. --Francis Bacon, Novum Organum, 1620 Pace Will Rogers, I am not a member of any organized political party. I am a libertarian. As a fiscal conservative and social liberal, I have found at least something to like about each Republican or Democrat I have met. I have close friends in both camps, in which I have observed the following: no matter the issue under discussion, both sides are equally convinced that the evidence overwhelmingly supports their position. This surety is called the confirmation bias, whereby we seek and find confirmatory evidence in support of already existing beliefs and ignore or reinterpret disconfirmatory evidence. Now a functional magnetic resonance imaging (fMRI) study shows where in the brain the confirmation bias arises and how it is unconscious and driven by emotions. Psychologist Drew Westen led the study, conducted at Emory University, and the team presented the results at the 2006 annual conference of the Society for Personality and Social Psychology. © 1996-2006 Scientific American, Inc.

Keyword: Brain imaging; Emotions
Link ID: 9087 - Posted: 06.24.2010