A molecular pathway within the brain’s reward circuitry appears to contribute to alcohol abuse, according to laboratory mouse research supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH). The findings, published online today in Proceedings of the National Academy of Sciences, also provide evidence that the pathway may be a promising new target for the treatment of alcohol problems. The mammalian target of rapamycin complex 1, or mTORC1, is a group of proteins found in cells throughout the body. An important part of the cellular machinery, mTORC1 sends signals that help regulate the size and number of cells. Scientists have also found that it is involved in other cellular processes. For example, in the central nervous system, mTORC1 has been linked to processes related to learning and memory. Because problems in the cellular mechanisms that underlie learning and memory can contribute to alcohol abuse disorders, NIAAA-supported researchers at the Ernest Gallo Clinic and Research Center of the University of California, San Francisco (UCSF) hypothesized that mTORC1 might be involved in alcohol problems. In laboratory studies conducted with mice, researchers led by Dorit Ron, Ph.D., a Gallo Center principal investigator and a professor of neurology at UCSF, measured an increase in mTORC1 cellular products in the nucleus accumbens of mice that had consumed alcohol — an indication that alcohol activates the mTORC1 pathway. The nucleus accumbens is a brain region that in rodents and humans is part of the reward system that affects craving for alcohol and other addictive substances. They then showed that rapamycin, an immunosuppressant drug that blocks the mTORC1 pathway, decreased excessive alcohol consumption, binge drinking, and alcohol-seeking behavior in the rodents. Rapamycin is currently used to prevent the rejection of transplanted organs.

Keyword: Drug Abuse
Link ID: 14618 - Posted: 11.02.2010

Ben Goldacre When the BBC tells you, in a headline, that libido problems are in the brain and not in the mind, you might find yourself wondering what the difference between the two is supposed to be, and whether a science article can really be assuming – in 2010 – that its readers buy into a strange Cartesian dualism in which the self is contained by a funny little spirit entity in constant and elaborate pneumatic connection with the corporeal realm. But first let's consider the experiment they're reporting on. As far as we know (because this experiment has not yet been published, only presented at a conference), some researchers took seven women with a "normal" sex drive, and 19 women diagnosed with "hypoactive sexual desire disorder". Participants watched a series of erotic films in a scanner while an MRI machine took images of blood flow in their brains: the women with a normal sex drive had an increased flow of blood to some parts of their brain associated with emotion, while those with low libido did not. Dr Michael Diamond, one of the researchers, tells the Mail: "Being able to identify physiological changes, to me provides significant evidence that it's a true disorder as opposed to a societal construct". In the Metro, he goes further: "Researcher Dr Michael Diamond said the findings offer 'significant evidence' that persistent low sex drive – known as hypoactive sexual desire disorder (HSDD) – is a genuine physiological disorder and not made up." © Guardian News and Media Limited 2010

Keyword: Brain imaging; Sexual Behavior
Link ID: 14617 - Posted: 11.02.2010

by Nathan Collins Could a fetus lying in the womb be planning its future? The question comes from the discovery that brain areas thought to be involved in introspection and other aspects of consciousness are fully formed in newborn babies. Resting state networks (RSNs), sometimes called the "dark energy of the brain", are patterns of low-frequency brain activity that are constantly active, even when a person is asleep. Activity in one RSN, the default mode network, drops when someone is engaged in a task, and it may be involved in introspective activities like envisioning the future – what some would call a facet of consciousness. Previous studies suggest that this network only fully develops during childhood, but David Edwards and colleagues at Imperial College London have now shown it is fully formed at birth. The finding came as the team investigated the relationship between RSNs and cognitive functions. They scanned the brains of 70 babies born up to three months early, whose development served as a proxy for fetal development. While rates of progression varied, RSNs for vision, touch, movement and decision-making were largely complete by 40 weeks, as was the default mode network. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain; Attention
Link ID: 14616 - Posted: 11.02.2010

By APRIL DEMBOSKY SACRAMENTO — In the three years since her son Diego was given a diagnosis of autism at age 2, Carmen Aguilar has made countless contributions to research on this perplexing disorder. She has donated all manner of biological samples and agreed to keep journals of everything she’s eaten, inhaled or rubbed on her skin. Researchers attended the birth of her second son, Emilio, looking on as she pushed, leaving with Tupperware containers full of tissue samples, the placenta and the baby’s first stool. Now the family is in yet another study, part of an effort by a network of scientists across North America to look for signs of autism as early as 6 months. (Now, the condition cannot be diagnosed reliably before age 2.) And here at the MIND Institute at the University of California Davis Medical Center, researchers are watching babies like Emilio in a pioneering effort to determine whether they can benefit from specific treatments. So when Emilio did show signs of autism risk at his 6-month evaluation — not making eye contact, not smiling at people, not babbling, showing unusual interest in objects — his parents eagerly accepted an offer to enroll him in a treatment program called Infant Start. The treatment is based on a daily therapy, the Early Start Denver Model, that is based on games and pretend play. It has been shown in randomized trials to significantly improve I.Q., language and social skills in toddlers with autism, and researchers say it has even greater potential if it can be started earlier. Copyright 2010 The New York Times Company

Keyword: Autism
Link ID: 14615 - Posted: 11.02.2010

By PAM BELLUCK About half of adolescents who recovered from major depression became depressed again within five years, regardless of what treatment or therapy they received to get over their initial depression, a new study shows. The study, published Monday in Archives of General Psychiatry, also found that girls were more likely to have another major depression, which surprised researchers because, as adults, women have not been considered more likely to have a recurrence than men. In the study, nearly 200 adolescents, 12 to 17, received 12 weeks of fluoxetine (Prozac), cognitive behavioral therapy, both, or a placebo pill. (Those not receiving cognitive therapy met with a psychiatrist for basic support.) Placebo-takers who did not improve after 12 weeks could choose any of the other treatments. Researchers had previously found that those receiving the Prozac-and-cognitive-therapy combination recovered faster from the first depression. So they expected those youths to be less prone to another depression. But that did not happen. After 36 weeks, improvement for everyone was similar, researchers said, and by two years most completely recovered. But by five years, 47 percent suffered another major depression, no matter what treatment had helped them recover. Copyright 2010 The New York Times Company

Keyword: Depression; Development of the Brain
Link ID: 14614 - Posted: 11.02.2010

People who take regular exercise during their free time are less likely to have symptoms of depression and anxiety, a study of 40,000 Norwegians has found. But physical activity which is part and parcel of the working day does not have the same effect, it suggests. Writing in the British Journal of Psychiatry, the researchers said it was probably because there was not the same level of social interaction. The charity Mind said that exercise and interaction aids our mental health. Higher levels of social interaction during leisure time were found to be part of the reason for the link. Researchers from the Institute of Psychiatry at King's College London teamed up with academics from the Norwegian Institute of Public Health and the University of Bergen in Norway to conduct the study. Participants were asked how often, and to what degree, they undertook physical activity in their leisure time and during the course of their work. Researchers also measured participants' depression and anxiety using the Hospital Anxiety and Depression Scale. BBC © MMX

Keyword: Depression
Link ID: 14613 - Posted: 11.01.2010

Alcohol is more harmful than heroin or crack, according to a study published in medical journal the Lancet. The report is co-authored by Professor David Nutt, the former UK chief drugs adviser who was sacked by the government in October 2009. It ranks 20 drugs on 16 measures of harm to users and to wider society. Tobacco and cocaine are judged to be equally harmful, while ecstasy and LSD are among the least damaging. Prof Nutt refused to leave the drugs debate when he was sacked from his official post by the former Labour Home Secretary, Alan Johnson. He went on to form the Independent Scientific Committee on Drugs, a body which aims to investigate the drug issue without any political interference. One of its other members is Dr Les King, another former government adviser who quit over Prof Nutt's treatment. Members of the group, joined by two other experts, scored each drug for harms including mental and physical damage, addiction, crime and costs to the economy and communities. BBC © MMX

Keyword: Drug Abuse
Link ID: 14612 - Posted: 11.01.2010

By SINDYA N. BHANOO The ancestors of humans and other primates like apes and monkeys may have originated in Asia, not Africa, a new study in the journal Nature reports. There has long been debate about the matter, but a recent discovery of anthropoid fossils including two previously unidentified species and one known species provides new clues. The fossils are about 38 million years old and were uncovered in a rock formation in southern Libya. The anthropoids were small, rodent-size creatures that looked similar to larger, modern-day primates, but weighed just 4 to 17 ounces. “At least one of these anthropoids appears to be clearly related to the older Asian form described in Myanmar,” said Jean-Jacques Jaeger, a paleontologist at the University of Poitiers in France and the study’s lead author. “This indicates that there was migration from Asia.” But there is another possibility: that the anthropoids originated in Africa and migrated to Asia, and that they have even older ancestors in Africa that have not yet been discovered. Copyright 2010 The New York Times Company

Keyword: Evolution
Link ID: 14611 - Posted: 11.01.2010

by Liz Day Dating advice, guys: Looking "masculine" may not get you anywhere with the ladies. Skin tone is what really makes a difference. Or so say researchers from University of Bristol and Brunel University, who published in a recent issue of online science journal PLoS ONE. They found that color information is more influential than shape information, upending prior thought on masculinity's link to attractiveness. Previous research studies had suggested that female animals prefer males with exaggerated male traits, such as large antlers and eye-catching peacock tails. Souped-up levels of testosterone are thought to contribute to the very masculine features, while also stressing the immune system. Thus, only high quality males can "afford" exposure to immune stress. Succinctly put, males with masculine shaped faces would appear to be more attractive, healthier partners for mating. Instead, this study found that skin color trumped masculine facial features. To clarify, skin color was measured in tones of lightness, redness and yellowness, and did not involve race or ethnicity. The authors believe that color matters because it fluctuates and is condition-dependent. Thus, skin color could better signal the health of a male partner at that moment, instead of an evolutionary facial structure that has been inherited over generations. © 2010 Discovery Communications, LLC

Keyword: Sexual Behavior; Evolution
Link ID: 14610 - Posted: 11.01.2010

By Wynne Parry, A group of scientists has genetically altered mice so they could "smell" light. That is their neurons responded to light in the same way they would to an odor. This allowed them to study the brain's response without having to deal with the complications associated with smelling. The approach the scientists used to help the mice "smell" the light is called optogenetics. The method uses light to control actions within other specific cells and is broadly applicable. The noses of mice (and humans) are chock-full of sensory neurons that respond to scent molecules that waft by. That odor information gets sent to the olfactory bulb, a part of the brain above the nasal cavities, where the sensory neurons meet up with relay neurons. These two types of neurons then meet within structures called glomeruli. "If you look at two cells receiving input from the same glomerulus, are they just passing it on [in] the same way, or is there something more to it?" said study researcher Venkatesh Murthy from Harvard University, who collaborated with others at Harvard, Cold Spring Harbor Laboratory and in India. A mouse has about 200,000 relay cells, with between 60 and 100 connected to each glomerulus, or hub. Identifying pairs of relay cells that connect to the same glomerulus is difficult, because when a rodent catches a whiff of something, multiple glomeruli go into action, according to Graeme Lowe, a neuroscientist at the independent Monell Chemical Senses Center who was not involved in the research. © The Christian Science Monitor

Keyword: Chemical Senses (Smell & Taste); Vision
Link ID: 14609 - Posted: 11.01.2010

A new stroke prevention clinic in Ottawa is helping patients treated for mini-strokes from developing the full-blown version, doctors report. A transient ischemic attack, or TIA, is a mild stroke that causes stroke symptoms such as sudden numbness of the face, arm or leg. The symptoms last for less than 24 hours and then resolve on their own without disabling neurological effects, but it is a marker for early risk of stroke. At the Ottawa Hospital Stroke Clinic, patients with TIA symptoms are quickly assessed in the emergency department (ED) and referred to the stroke clinic for brain imaging, medication adjustment, counselling about stroke risk factors and surgery in some cases. Dr. Mukul Sharma, deputy director of the Canadian Stroke Network, and his co-authors found that 3.2 per cent of people who experienced TIA at the stroke prevention clinic developed a full-blown stroke within 90 days, compared with about 10 per cent at other centres. "The beauty of this is that we added very few staff," said Sharma, lead author of the study in the November issue of the journal Stroke, and director of The Ottawa Hospital Stroke Clinic. A booking clerk was one of the few staff that was added as part of the program. "It really is that ability to juggle bookings and the acuity of the visit that I think make this process work. I've likened it to getting an orchestra playing the same tune." © CBC 2010

Keyword: Stroke
Link ID: 14608 - Posted: 10.30.2010

By MATTHEW PERRONE WASHINGTON -- Federal health regulators have decided not to approve an experimental diet pill called Qnexa, which had been touted by many experts as the most promising weight-loss drug in more than a decade. The drug's maker, Vivus Inc., said in a statement Thursday that the Food and Drug Administration declined to approve the drug in its present form. The agency asked for more study results and additional information on its possible health risks, including major cardiovascular events and risks for women of childbearing potential. The FDA did not ask for any new clinical studies, but more may be required if the agency's concerns aren't addressed, Vivus said. The company plans to respond to the FDA in about six weeks. "We remain confident in the efficacy and safety profile of Qnexa demonstrated in the clinical development program and look forward to continue working with the FDA towards the approval for the treatment of obesity," Vivus CEO Leland Wilson said in a statement. Vivus, based in Mountain View, Calif., is one of three small drugmakers racing to win approval for their weight-loss drugs. Many analysts picked Qnexa as the most promising contender because of the high level of weight loss reported in company studies: On average, patients lost more than 10 percent total body mass. That compared to weight loss of under 5 percent with drugs currently on the market, like Roche's Xenical. © 2010 The Associated Press

Keyword: Obesity
Link ID: 14607 - Posted: 10.30.2010

By Christof Koch If you have seen the recent Holly­wood blockbuster Inception, a movie that does to dreaming what The Matrix did for virtual reality, you may have been holding your breath as Ariadne, an architecture student, folded the streets of Paris over herself like a blanket. This stunning sequence, an homage to M. C. Escher, is testimony to the bizarre nature of dreams. Watching it made the neuroscientist in me reflect on what dreams are and how they relate to the brain. The first question is easy to answer. Dreams are vivid, sensorimotor hallucinations with a narrative structure. We experience them consciously—seeing, hearing and touching within environments that appear completely real (though curiously, we do not smell in our dreams). Nor are we mere passive observers: we speak, fight, love and run. Dream consciousness is not the same as wakeful consciousness. We are for the most part unable to introspect—to wonder about our uncanny ability to fly or to meet somebody long dead. Only rarely do we control our dreams; rather things happen, and we go along for the ride. Everyone dreams, including dogs, cats and other mammals. But sleep lab data reveal that people consistently underreport how often and how much. The reason is that dreams are ephemeral. Memory for dreams is very limited and largely restricted to the period before awakening. The only way to remember a dream is to immediately recall it on waking and then write it down or describe it to another person. Only then does its content become encoded in memory. © 2010 Scientific American,

Keyword: Sleep; Attention
Link ID: 14606 - Posted: 10.30.2010

By Laura Sanders The brain uses two different checks to guard against sloppy copy, a new study finds. By using a doctored word processor to sneak errors into typed words and surreptitiously fix typists’ real errors, researchers teased apart the various ways people catch their own mistakes. The study, published in the Oct. 29 Science, highlights the complexity of performance monitoring. Psychologist Gordon Logan and his colleague Matthew Crump of Vanderbilt University in Nashville recruited skilled typists — people who typed more than 40 words a minute using all of their fingers. These subjects were able to type a paragraph about the merits of border collies with over 90 percent accuracy. As the typists pecked away, researchers introduced common typing errors into about 6 percent of the words that appeared on a screen (changing sweat to swaet, swerat or swet, for instance). The program also corrected about 45 percent of the typists’ true errors. In questionnaires after the typing test, subjects by and large took the blame for the introduced errors and took credit for the researchers’ corrections. No matter what he actually typed, when the typist saw that the word on the screen matched the word he had intended to type, he assessed his own performance as accurate. © Society for Science & the Public 2000 - 2010

Keyword: Attention
Link ID: 14605 - Posted: 10.30.2010

Humans are not the only species to prefer to use their right hand -- chimpanzees also share the trait, according to a new study by Spanish scientists. The researchers reached their findings, published in the latest edition of the American Journal of Primatology, after observing 114 chimpanzees from two primate rescue centers, one in Spain and the other in Zambia. The primates were provided with food hidden inside tubes and the scientists monitored them to see which hand they used to get at it, either their fingers or with the help of tools. "The chimpanzees showed a preferential use of the right hand to get the food from the tube," the Catalan Institute of Human Palaeoecology and Social Evolution, which coordinated the study, said in a statement. "This feature had traditionally been considered exclusively human and had been believed to be caused by asymmetries observed in the human brain that are related to the realization of complicated activities that require the use and coordination of both hands." The study also found that female chimpanzees, like their human counterparts, are more likely to be right-handed than males. The researchers said this suggests "that just like in our species, there are shared biological factors, genetic and hormonal, that modulate the functioning of our brain." © 2010 Discovery Communications, LLC

Keyword: Laterality
Link ID: 14604 - Posted: 10.30.2010

Melissa Dahl writes: You know that saying "the left hand doesn't know what the right is doing"? For people with a strange disorder called alien hand syndrome, that's literally true -- the neuropsychiatric condition makes them feel as if one of their hands has taken on a mind of its own. "An alien hand is an arm and hand that moves when the person to whom that arm belongs does not intend it to move," says Dr. Ken Heilman, a neurologist at the University of Florida College of Medicine in Gainesville, Fla. Heilman goes on to note that there are many neurological conditions that cause an arm to move unintentionally -- like seizures or tremors, and movement disorders such as chorea, dystonia and athetosis. Here's the difference: In each of those cases, if the arm moves, it's pretty much just flailing about purposelessly, "but with an alien hand, the movement appears to be purposeful." Creepy. Heilman recalls one patient whose hands actually fought over fashion: Her right hand took a pair of red shoes out of the closet. Her left hand -- the "alien" hand -- pulled the red shoes out of her right hand, put them back and picked up a pair of blue shoes. When the right hand went again for the red shoes, the left hand slammed the closet door on the right hand. A German neurologist and psychiatrist named Kurt Goldstein was the first to report a case of alien hand syndrome in 1908. His patient's left hand seemed to do whatever it pleased, including, at least once, an attempt to throttle its owner. It's most commonly the result of an injury to an area of the brain called the corpus callosum. © 2010 msnbc.com

Keyword: Laterality; Attention
Link ID: 14603 - Posted: 10.30.2010

By Pallab Ghosh A US researcher has said he plans to electronically record and interpret dreams. Writing in the journal Nature, researchers said they have developed a system capable of recording higher-level brain activity. "We would like to read people's dreams," says the lead scientist Dr Moran Cerf. The aim is not to interlope, but to extend our understanding of how and why people dream. For centuries, people have been fascinated by dreams and what they might mean; in ancient Egypt for example, they were thought to be messages from the gods. More recently, dream analysis has been used by psychologists as a tool to understand the unconscious mind. But the only way to interpret dreams was to ask people about the subject of their dreams after they had woken up. The eventual aim of Dr Cerf's project is to develop a system that would enable psychologists to corroborate people's recollections of their dream with an electronic visualisation of their brain activity. "There's no clear answer as to why humans dream," according to Dr Cerf. "And one of the questions we would like to answer is when do we actually create this dream?" BBC © MMX

Keyword: Sleep; Brain imaging
Link ID: 14602 - Posted: 10.28.2010

by Liz Day A recent study used functional magnetic resonance imaging to see how love affects the brain. Its calculations of love has attracted plenty of attention. For example, the time taken to "fall in love" clocks in at about one-fifth of a second, not the six months of romantic dinners and sharing secrets some might expect. Also, 12 areas of the brain work together during the love process, releasing euphoria-inducing chemicals like dopamine, oxytocin, adrenaline and vasopressin. Love's high is similar to cocaine's rush. Love influences sophisticated intellectual processes of the brain too. When a person feels in love, their mental representation, metaphors and even body image are also affected. Researchers from Syracuse University, West Virginia University and the Geneva University Psychiatric Center retrospectively reviewed pertinent neuroimaging literature. They published their findings in a recent issue of the Journal of Sexual Medicine. Overall, they found, love is really good for you. Couples who had just fallen in love had significantly higher levels of nerve growth factor, or NGF. NGF is crucial to the survival of sympathetic and sensory neurons. Some believe NGF can reduce neural degeneration. Not a bad side effect. © 2010 Discovery Communications, LLC

Keyword: Sexual Behavior; Attention
Link ID: 14601 - Posted: 10.28.2010

by Catherine de Lange It's a familiar feeling. After a large meal you feel full, but a glimpse of a slice of gooey, rich chocolate cake is enough to get you salivating again. Could it be possible to prevent our brains from responding so strongly to the sight of tantalising treats? The answer is yes, according to new research which suggests that some anti-obesity drugs work by dulling this brain response to the sight of appetising, high-calorie food. Paul Fletcher from the University of Cambridge and colleagues wanted to understand how drugs that help people lose weight affect the brain. To find out, they gave 24 obese people either the anti-obesity drug Sibutramine or a placebo for two weeks and then scanned their brains while showing them pictures of high- or low-calorie foods, such as chocolate cake or broccoli. Not only did volunteers taking the drug eat less and lose weight during the two weeks of the study, their hypothalamus and amygdala – areas of the brain involved in reward – also responded more weakly to the sight of high-calorie foods than those given the placebo. "This is the first evidence that an anti-obesity drug changes brain function," says Ed Bullmore, who is also at the University of Cambridge and also worked on the study. More importantly, says Bullmore, it shows how these brain changes are correlated with a change in eating behaviour, and ultimately weight loss. © Copyright Reed Business Information Ltd.

Keyword: Obesity; Drug Abuse
Link ID: 14600 - Posted: 10.28.2010

by Adrian M Owen You might think it's obvious that one person is smarter than another. But there are few more controversial areas of science than the study of intelligence and, in reality, there's not even agreement among researchers about what this word actually means. Unlike weight and height, which are unambiguous, there is no absolute measure of intelligence, just as there are no absolute measures of honesty or physical fitness. Nonetheless, over the decades, legions of scientists have devised tests that can show that one person is smarter than another just as surely as Olympic events can shed light on how much you can lift or how far you can jump. Now my team at the UK Medical Research Council's Cognition and Brain Sciences Unit in Cambridge has come up with the ultimate test of intelligence. Like many researchers before us, we began by looking for the smallest number of tests that could cover the broadest range of cognitive skills that are believed to contribute to intelligence, from memory to planning. But we went one step further. Thanks to recent work with brain scanners, we could make sure that the tests involved as much of the brain as possible – from the outer layers, responsible for higher thought, to deeper-lying structures such as the hippocampus, which is involved in memory. Here's a longer explanation of the theory and evidence that we used when devising the tests. © Copyright Reed Business Information Ltd.

Keyword: Intelligence; Attention
Link ID: 14599 - Posted: 10.28.2010