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By Adrian Cho Whether they're from humans, whales, or elephants, the brains of many mammals are covered with elaborate folds. Now, a new study shows that the degree of this folding follows a simple mathematical relationship—called a scaling law—that also explains the crumpling of paper. That observation suggests that the myriad forms of mammalian brains arise not from subtle developmental processes that vary from species to species, but rather from the same simple physical process. In biology, it rare to find a mathematical relationship that so tightly fits all the data, say Georg Striedter, a neuroscientist at the University of California, Irvine. "They've captured something," he says. Still, Striedter argues that the scaling law describes a pattern among fully developed brains and doesn't explain how the folding in a developing brain happens. The folding in the mammalian brain serves to increase the total area of the cortex, the outer layer of gray matter where the neurons reside. Not all mammals have folded cortices. For example, mice and rats have smooth-surfaced brains and are "lissencephalic." In contrast, primates, whales, dogs, and cats have folded brains and are "gyrencephalic." For decades, scientists have struggled to relate the amount of folding in a species' brain to some other characteristic. For example, although animals with tiny brains tend to have smooth ones, there is no clean relationship between the amount of folding—measured by the ratio of the total area of the cortex to the exposed outer surface of the brain—and brain mass. Make a plot of folding versus brain mass for various species and the data points fall all over and not on a unified curve. Similarly, there is no clean relationship between the amount of folding and the number of neurons, the total area of the cortex, or the thickness of the cortex. © 2015 American Association for the Advancement of Science

Keyword: Development of the Brain; Evolution
Link ID: 21133 - Posted: 07.04.2015

By BARRY MEIER and DANIELLE IVORY In a small brick building across the street from a Taco Bell in Marrero, La., patients enter a clear plastic capsule and breathe pure oxygen. The procedure, known as hyperbaric oxygen therapy, uses a pressurized chamber to help scuba divers overcome the bends and to aid people sickened by toxic gases. But Dr. Paul G. Harch, who operates the clinic there on the outskirts of New Orleans, offers it as a concussion treatment. One patient, Rashada Parks, said that she had struggled with neck pain, mood swings and concentration problems ever since she fell and hit her head more than three years ago. Narcotic painkillers hadn’t helped her, nor had antidepressants. But after 40 hourlong treatments, or dives, in a hyperbaric chamber, her symptoms have subsided. “I have hope now,” Ms. Parks said. “It’s amazing.” Three studies run at a taxpayer cost of about $70 million have all come to a far different conclusion. They found that the benefits of hyperbaric oxygen reported by patients like Ms. Parks may have resulted from a placebolike effect, not the therapy’s supposed ability to repair and regenerate brain cells. But undeterred, advocates of the treatment recently persuaded lawmakers to spend even more public money investigating whether the three studies were flawed. A growing industry has developed around concussions, with entrepreneurs, academic institutions and doctors scrambling to find ways to detect, prevent and treat head injuries. An estimated 1.7 million Americans are treated every year after suffering concussions from falls, car accidents, sports injuries and other causes. While the vast majority quickly recover with rest, a small percentage of patients experience lingering effects a year or longer afterward. Along with memory issues, symptoms can include headaches, dizziness and vision and balance problems. © 2015 The New York Times Company

Keyword: Brain Injury/Concussion
Link ID: 21132 - Posted: 07.04.2015

By Kelly Servick How many times would you give your neighbor an electric shock to earn a few extra bucks? Your answer could be more malleable than you think. A new study finds that two common drugs—an antidepressant and a treatment for Parkinson’s disease—can influence moral decisions, a discovery that could help unravel specific mechanisms behind aggression and eventually help researchers design treatments for antisocial behavior. Previous research has linked two neurotransmitters, the brain’s signaling molecules, to our willingness to inflict harm. Serotonin appears to help keep us civil; it’s reduced in the brains of violent offenders, for example. Dopamine, meanwhile, has been shown to prompt aggression in animals, and it’s elevated in a certain part of the brain in people with psychopathic behavior. But measuring how these neurotransmitters contribute to moral decision-making is hard to do in the lab. Many studies rely on theoretical questions like the so-called trolley dilemma, which asks a person whether they would redirect an oncoming train to kill someone if it would save the lives of several others in its path. A person’s answer might not always reflect how they would behave in real life, however. So neuroscientist Molly Crockett of the University of Oxford in the United Kingdom and her colleagues developed a lab test with real consequences. They asked subjects to make a series of decisions about how many moderately painful electric shocks to deliver to themselves or to others. Half the questions gave volunteers a chance to earn money by inflicting self-harm. (For example: “Would you rather endure seven shocks to earn $10 or 10 shocks to earn $15?”) The other half offered the same type of decision, except that someone else stood to be shocked. At the end of the experiment, one of these choices was randomly selected and carried out: The decision-maker got paid, and either they or another person—waiting in a different room—got a series of painful zings on the wrist. Any answer could be the one with real consequences, so “people have to sort of put their money where their mouth is,” Crockett says. © 2015 American Association for the Advancement of Science

Keyword: Emotions
Link ID: 21131 - Posted: 07.04.2015

Spider-like cells inside the brain, spinal cord and eye hunt for invaders, capturing and then devouring them. These cells, called microglia, often play a beneficial role by helping to clear trash and protect the central nervous system against infection. But a new study by researchers at the National Eye Institute (NEI) shows that they also accelerate damage wrought by blinding eye disorders, such as retinitis pigmentosa. NEI is part of the National Institutes of Health. “These findings are important because they suggest that microglia may provide a target for entirely new therapeutic strategies aimed at halting blinding eye diseases of the retina,” said NEI Director, Paul A. Sieving, M.D. “New targets create untapped opportunities for preventing disease-related damage to the eye, and preserving vision for as long as possible.” The findings were published in the journal EMBO Molecular Medicine. Retinitis pigmentosa, an inherited disorder that affects roughly 1 in 4,000 people, damages the retina, the light-sensitive tissue at the back of the eye. Research has shown links between retinitis pigmentosa and several mutations in genes for photoreceptors, the cells in the retina that convert light into electrical signals that are sent to the brain via the optic nerve. In the early stages of the disease, rod photoreceptors, which enable us to see in low light, are lost, causing night blindness. As the disease progresses, cone photoreceptors, which are needed for sharp vision and seeing colors, can also die off, eventually leading to complete blindness.

Keyword: Vision; Glia
Link ID: 21130 - Posted: 07.04.2015

By SINDYA N. BHANOO It may be possible to diagnose autism by giving children a sniff test, a new study suggests. Most people instinctively take a big whiff when they encounter a pleasant smell and limit their breathing when they encounter a foul smell. Children with autism spectrum disorder don’t make this natural adjustment, said Liron Rozenkrantz, a neuroscientist at the Weizmann Institute of Science in Israel and one of the researchers involved with the study. She and her colleagues report their findings in the journal Current Biology. They presented 18 children who had an autism diagnosis and 18 typically developing children with pleasant and unpleasant odors and measured their sniff responses. The pleasant smells were rose and soap, and the unpleasant smells were sour milk and rotten fish. Typically developing children adjusted their sniffing almost immediately — within about 305 milliseconds. Children with autism did not respond as rapidly. As they were exposed to the smells, the children were watching a cartoon or playing a video game. “It’s a semi-automated response,” Ms. Rozenkrantz said. “It does not require the subject’s attention.” Using the sniff test alone, the researchers, who had not been told which children had autism, were able to correctly identify those with autism 81 percent of the time. They also found that the farther removed an autistic child’s sniff response was from the average for typically developing children, the more severe the child’s social impairments were. © 2015 The New York Times Company

Keyword: Autism; Chemical Senses (Smell & Taste)
Link ID: 21129 - Posted: 07.04.2015

By Victoria Gill Science reporter, BBC News Cat v mouse: it is probably the most famous predator-prey pairing, enshrined in idioms and a well-known cartoon. And cats, it turns out, even have chemical warfare in their anti-mouse arsenal - contained in their urine. Researchers found that when very young mice were exposed to a chemical in cat urine, they were less likely to avoid the scent of cats later in life. The findings were presented at the Society for Experimental Biology's annual meeting in Prague. The researchers, from the AN Severtov Institute of Ecology and Evolution in Moscow, had previously found that the compound - aptly named felinine - causes pregnant mice to abort. Dr Vera Voznessenskaya explained that mice have a physiological response to this cat-specific compound. Chemical-sensing mouse neurons in the mouse's brain pick up the scent, triggering a reaction which includes an increase in the levels of stress hormones. "It's something that has existed in cats and mice for thousands of years," said Dr Voznessenskaya. This new study revealed that baby mice exposed to the compound during a "critical period" in their development would, as adults, react quite differently to their arch enemy's smell. The team exposed one-month-old mice to the chemical over two weeks. When they were tested later for their reaction, they were much less likely to flee the same scent. The interaction between cats and mice has a long history "Their physical sensitivity [to the chemical] was actually actually much higher," Dr Voznessenskaya explained. "More of their receptors detect the compound and they produce higher levels of stress hormone." Despite this though, mice raised around the unmistakable scent of cat pee are less inclined to show signs of fear, or to flee when they sniff it out. © 2015 BBC.

Keyword: Chemical Senses (Smell & Taste); Hormones & Behavior
Link ID: 21128 - Posted: 07.04.2015

by Sarah Zielinski Seabirds called shearwaters manage to navigate across long stretches of open water to islands where the birds breed. It’s not been clear how the birds do this, but there have been some clues. When scientists magnetically disturbed Cory’s shearwaters, the birds still managed to find their way. But when deprived of their sense of smell, the shearwaters had trouble homing in on their final destination. Smell wouldn’t seem to be all that useful out over the ocean, especially with winds and other atmospheric disturbances playing havoc on any scents wafting through the air. But now researchers say they have more evidence that shearwaters are using olfactory cues to navigate. Andrew Reynolds of Rothamsted Research in Harpenden, England, and colleagues make their case June 30 in the Proceedings of the Royal Society B. Messing with Cory’s shearwaters or other seabirds, like researchers did in earlier studies, wasn’t a good option, the researchers say, because there are conservation concerns when it comes to these species. Instead, they attached tiny GPS loggers to 210 shearwaters belonging to three species: Cory’s shearwaters, Scopoli’s shearwaters and Cape Verde shearwaters. But how would the birds’ path reveal how they were navigating? If they were using olfactory cues, the team reasoned, the birds wouldn’t take a straight path to their target. Instead, they would fly straight for a time, guided in that direction by a particular smell. When they lost that scent, their direction would change, until they picked up another scent that could guide them. And only when a bird got close would it use landmarks, other birds and the odor of the breeding colony as guides. If the birds were using some other method of navigation — or randomly searching for where to go — their paths would look much different. © Society for Science & the Public 2000 - 2015

Keyword: Chemical Senses (Smell & Taste); Animal Migration
Link ID: 21127 - Posted: 07.04.2015

By SINDYA N. BHANOO Learning can be traced back to individual neurons in the brain, according to a new study. “What we wanted to do was see if we could actually create a new association — a memory — and see if we would be able to see actual change in the neurons,” said Matias Ison, a neuroscientist at the University of Leicester in England and one of the study’s authors. He and his colleagues were able to monitor the brain activity of neurosurgical patients at UCLA Medical Center. The patients already had electrodes implanted in their medial temporal lobes for clinical reasons. The patients were first presented with images of notable people — like Jennifer Aniston, Clint Eastwood and Halle Berry. Then, they were shown images of the same people against different backdrops — like the Eiffel Tower, the Leaning Tower of Pisa and the Sydney Opera House. The same neurons that fired for the images of each of the actors also fired when patients were shown the associated landmark images. In other words, the researchers were able to watch as the patients’ neurons recorded a new memory — not just of a particular person, but of the person at a particular place. © 2015 The New York Times Company

Keyword: Learning & Memory
Link ID: 21126 - Posted: 07.02.2015

Jon Hamilton If you run into an old friend at the train station, your brain will probably form a memory of the experience. And that memory will forever link the person you saw with the place where you saw them. For the first time, researchers have been able to see that sort of link being created in people's brains, according to a study published Wednesday in the journal Neuron. The process involves neurons in one area of the brain that change their behavior as soon as someone associates a particular person with a specific place. "This type of study helps us understand the neural code that serves memory," says Itzhak Fried, an author of the paper and head of the Cognitive Neurophysiology Laboratory at UCLA. It also could help explain how diseases like Alzheimer's make it harder for people to form new memories, Fried says. The research is an extension of work that began more than a decade ago. That's when scientists discovered special neurons in the medial temporal lobe that respond only to a specific place, or a particular person, like the actress Jennifer Aniston. The experiment used a fake photo of actor Clint Eastwood and Pisa's leaning tower to test how the brain links person and place. More recently, researchers realized that some of these special neurons would respond to two people, but only if the people were connected somehow. For example, "a neuron that was responding to Jennifer Aniston was also responding to pictures of Lisa Kudrow," [another actress on the TV series Friends], says Matias Ison of the University of Leicester in the U.K. © 2015 NPR

Keyword: Learning & Memory; Attention
Link ID: 21125 - Posted: 07.02.2015

By Gretchen Vogel The 2009 H1N1 influenza pandemic left a troubling legacy in Europe: More than 1300 people who received a vaccine to prevent the flu developed narcolepsy, an incurable, debilitating condition that causes overpowering daytime sleepiness, sometimes accompanied by a sudden muscle weakness in response to strong emotions such as laughter or anger. The manufacturer, GlaxoSmithKline (GSK), has acknowledged the link, and some patients and their families have already been awarded cpmpensation. But how the vaccine might have triggered the condition has been unclear. In a paper in Science Translational Medicine (STM) this week, researchers offer a possible explanation. They show that the vaccine, called Pandemrix, triggers antibodies that can also bind to a receptor in brain cells that help regulate sleepiness. The work strongly suggests that Pandemrix, which was given to more than 30 million Europeans, triggered an autoimmune re action that led to narcolepsy in some people who are genetically at risk. “They put together quite a convincing picture and provide a plausible explanation for what has happened,” says Pasi Penttinen, who heads the influenza program at the European Centre for Disease Prevention and Control in Stockholm. “It’s really the kind of work we’ve been waiting for for 5 years.” But the results still need to be confirmed in a larger study, the authors and other narcolepsy researchers say. A 2013 paper in STM by another group, documenting a different type of vaccine-triggered autoimmune re action, was retracted after the results proved irreproducible (Science, 1 August 2014, p. 498). © 2015 American Association for the Advancement of Science

Keyword: Sleep; Neuroimmunology
Link ID: 21124 - Posted: 07.02.2015

by Andy Coghlan "I was completely revitalised," says Karen. "Suddenly, I could be sociable again. I would go to work, go home, eat dinner and feel restless." Karen (not her real name) experienced this relief from chronic fatigue syndrome while taking a drug that is usually used to treat the blood cancer lymphoma and rheumatoid arthritis (see "Karen's experience", below). She was one of 18 people with CFS who reported improvements after taking rituximab as part of a small trial in Bergen, Norway. The results could lead to new treatments for the condition, which can leave people exhausted and housebound. Finding a cause for CFS has been difficult. Four years ago, claims that a mouse virus was to blame proved to be unfounded, and some have suggested the disease is psychosomatic. The latest study implicates the immune system, at least in some cases. Rituximab wipes out most of the body's B-cells, which are the white blood cells that make antibodies. Øystein Fluge and Olav Mella of the Haukeland University Hospital in Bergen noticed its effect on CFS symptoms in 2004, when they used the drug to treat lymphoma in a person who happened to also have CFS. Several months later, the person's CFS symptoms had disappeared. A small, one-year trial in 2011 found that two-thirds of those who received rituximab experienced relief, compared with none of the control group. The latest study, involving 29 people with CFS, shows that repeated rituximab infusions can keep symptoms at bay for years. © Copyright Reed Business Information Ltd

Keyword: Depression; Neuroimmunology
Link ID: 21123 - Posted: 07.02.2015

Nancy Shute Powerful antipsychotic medications are being used to treat children and teenagers with ADHD, aggression and behavior problems, a study finds, even though safer treatments are available and should be used first. "There's been concern that these medications have been overused, particularly in young children," says Mark Olfson, a professor of psychiatry at Columbia University who led the study. It was published Wednesday in JAMA Psychiatry. "Guidelines and clinical wisdom suggest that you really should be using a high degree of caution and only using them when other treatments have failed, as a last resort." Olfson and his colleagues looked at prescription data from about 60 percent of the retail pharmacies in the United States in 2006, 2008 and 2010. That included almost 852,000 children, teenagers and young adults. Teens were most likely to be prescribed antipsychotics, with 1.19 percent getting the drugs in 2010, compared to 0.11 percent in younger children. Boys were more likely to be given the medications. Antipsychotic medications like clozapine and olanzapine are used to treat schizophrenia, bipolar disorder and some symptoms of autism. They have not been approved by the Food and Drug Administration to treat aggression and ADHD, but are prescribed off label to reduce disruptive behavior. FDA Debates Safety Of Antipsychotic Drugs In Kids Use of antipsychotics in children has been questioned because the drugs can have serious side effects, including tremors, weight gain, increased diabetes risk and elevated cholesterol. © 2015 NPR

Keyword: Drug Abuse; Development of the Brain
Link ID: 21122 - Posted: 07.02.2015

Boys are more likely than girls to receive a prescription for antipsychotic medication regardless of age, researchers have found. Approximately 1.5 percent of boys ages 10-18 received an antipsychotic prescription in 2010, although the percentage falls by nearly half after age 19. Among antipsychotic users with mental disorder diagnoses, attention deficit hyperactivity disorder (ADHD) was the most common among youth ages 1-18, while depression was the most common diagnosis among young adults ages 19-24 receiving antipsychotics. Despite concerns over the rising use of antipsychotic drugs to treat young people, little has been known about trends and usage patterns in the United States before this latest research, which was funded by the National Institute of Mental Health (NIMH), part of the National Institutes of Health. Mark OlfsonExternal Web Site Policy, M.D., M.P.H., of the Department of Psychiatry, College of Physicians and Surgeons and Columbia University and New York State Psychiatric Institute, New York City, and colleagues Marissa King, Ph.D., Yale, New Haven, Connecticut, and Michael Schoenbaum, Ph.D., NIMH, report their findings on July 1 in JAMA Psychiatry. “No prior study has had the data to look at age patterns in antipsychotic use among children the way we do here,” said co-author Michael Schoenbaum, Ph.D., senior advisor for mental health services, epidemiology and economics at NIMH. “What’s especially important is the finding that around 1.5 percent of boys aged 10-18 are on antipsychotics, and then this rate abruptly falls by half, as adolescents become young adults.” “Antipsychotics should be prescribed with care,” says Schoenbaum. “They can adversely affect both physical and neurological function and some of their adverse effects can persist even after the medication is stopped.”

Keyword: Development of the Brain; Drug Abuse
Link ID: 21121 - Posted: 07.02.2015

by Michael Le Page It's good to be mixed-up. People whose parents are distantly related are, on average, taller, smarter and better educated than those whose parents are close relatives. Based on what we know about plants and animals, biologists have long suspected that people of mixed parentage have a genetic advantage. Now an extensive study may have confirmed the hunch. "It does imply that people who come from very different ancestry would be a bit taller and a bit more cognitively able," says team member Jim Wilson of the University of Edinburgh, UK. It has long been known that children are more likely to suffer from genetic diseases if their parents are close relatives, because they may inherit the same harmful gene variants from their mother and father. To probe the wider implications, Wilson and his colleagues analysed genome and life history data from 110 genome studies involving 350,000 people from Africa, Asia, Europe and North America. They were surprised to find no evidence of a link between having closely related parents and most of the traits they looked at, such as cholesterol levels, blood pressure and rates of diabetes. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 21120 - Posted: 07.02.2015

By Ariel Sabar In televised remarks from the East Room of the White House on April 2, 2013, President Obama unveiled a scientific mission as grand as the Apollo program. The goal wasn’t outer space, but a frontier every bit as bewitching: the human brain. Obama challenged the nation’s “most imaginative and effective researchers” to map in real time the flickerings of all 100 billion nerve cells in the brain of a living person, a voyage deep into the neural cosmos never attempted at so fine a scale. A panoramic view of electric pulses pinballing across the brain could lead to major new understandings of how we think, remember and learn, and how ills from autism to Alzheimer’s rewire our mental circuitry. “We have a chance to improve the lives of not just millions,” the president said, “but billions of people on this planet.” The next month, six miles from the White House, a Harvard professor named Florian Engert grabbed a mic and, in front of the nation’s top neuroscientists, declared Obama’s effort essentially futile. “We have those data now,” said Engert, who, in a room full of professorial blazers and cardigans, was wearing a muscle shirt that afforded ample views of his bulging biceps. “We discovered they’re actually not all that useful.” (“I think whole-brain imaging is just a bunch of bull----,” is how he put it to me later.) To the other researchers, he must have sounded like a traitor. Engert, who is 48, was basically the first person on the planet to observe a brain in the wall-to-wall way Obama envisioned. He and his colleagues had done it with a sci-fi-worthy experiment that recorded every blip of brain activity in a transparent baby zebra­fish, a landmark feat published just a year earlier in the marquee scientific journal Nature. For Engert to suggest that the president’s brain quest was bunk was a bit like John Glenn returning from orbit and telling JFK not to bother with a lunar landing.

Keyword: Brain imaging
Link ID: 21119 - Posted: 07.02.2015

By Erika Beras Marijuana is the drug of choice for people who drink alcohol. And people who use both are twice as likely to do so at the same time than to indulge in just one or the other. That’s according to a study in the journal Alcoholism: Clinical and Experimental Research. [Meenakshi S. Subbaraman and William C. Kerr, Simultaneous Versus Concurrent Use of Alcohol and Cannabis in the National Alcohol Survey The data came from self-reported answers that more than 8,600 people provided to what’s called the National Alcohol Surveys, done by phone in 2005 and 2010. People who used pot and alcohol were about twice as likely to drive drunk than those who just drank. And they doubled their chances of what are referred to as negative social consequences, such as arrests, fights and job problems. Meanwhile, another new study finds that if you’re chronically stoned, you’re more likely to remember things differently from how they happened, or not at all. Researchers showed a series of words to people who do not use marijuana and to regular pot users who had not partaken in a month. A few minutes later, all participants were shown the same list of words along with other words. The volunteers were then asked to identify only the original words. The pot smokers thought more of the new words were in the original list than did the nonusers. And brain scans revealed that the regular pot users showed less activity in brain regions associated with memory and cognitive resources than did the nonusers. The study is in the journal Molecular Psychiatry. [J. Riba et al, Telling true from false: cannabis users show increased susceptibility to false memories] © 2015 Scientific American

Keyword: Drug Abuse; Learning & Memory
Link ID: 21118 - Posted: 07.02.2015

by Lisa Grossman Marriage for all, no gay gene required. For same-sex couples in the US, 26 June was a landmark date: the Supreme Court legalised marriage between two men or two women in all 50 states. "[Same-sex couples] ask for equal dignity in the eyes of the law," wrote Associate Justice Anthony Kennedy in the decision. "The Constitution grants them that right." But one thing the decision didn't do was declare sexual orientation a "suspect class" under the law, which would have given it the same protection as race. One of the criteria for this classification is that the trait must be immutable – an argument that the gay rights movement has internalised under the banner of "we're born this way". But although there is some evidence that sexual orientation has a genetic component, most scientists agree that it's not that simple. "There's significant consensus in the scientific community that there's enough different interacting causes for sexual orientation that two different individuals can be gay for different combinations of reasons," says sexuality researcher Lisa Diamond at the University of Utah. "I think all the evidence suggests that we're born with an underlying capacity and then that capacity interacts with a whole bunch of other influences," she says – whether they be prenatal, genetic or environmental. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior
Link ID: 21117 - Posted: 07.01.2015

By Dina Fine Maron The game is a contemporary of the original Nintendo but it still appeals to today’s teens and lab monkeys alike—which is a boon for neuroscientists. It offers no lifelike graphics. Nor does it boast a screen. Primate players—whether human or not—are simply required to pull levers and replicate patterns of flashing lights. Monkeys get a banana-flavored treat as a reward for good performance whereas kids get nickels. But the game's creators are not really in it for fun. It was created by toxicologists at the U.S. Food and Drug Administration in the 1980s to study how chronic exposure to marijuana smoke affects the brain. Players with trouble responding quickly and correctly to the game’s commands may have problems with short-term memory, attention or other cognitive issues. The game has since been adapted to address a different question: whether anesthetics used to knock pediatric patients unconscious during surgery and diagnostic tests could affect a youngster's long-term neural development and cognition. Despite 20 years’ worth of experiments in young rodents and monkeys, there have been few definitive answers. To date, numerous studies suggest that being put under with anesthesia early in life seems somehow related to future cognitive problems. But whether this association is causal or merely coincidence is unclear. Researchers do know that the young human brain is exceptionally sensitive. When kids are exposed to certain harmful chemicals in their formative years, that experience can fundamentally alter the brain’s architecture by misdirecting the physical connections between neurons or causing cell deaths. But unraveling whether anesthetics may fuel such long-term damage in humans remains a challenge. © 2015 Scientific American

Keyword: Development of the Brain; Sleep
Link ID: 21116 - Posted: 07.01.2015

by Colin Barras Men often lose their sex drive with age – and so, it seems do male Drosophila. Tsai-Feng Fu at the National Chi Nan University in Taiwan and his colleagues suspected that low levels of dopamine in the flies were to blame. Almost 300 neurones in the fruit-fly brain use dopamine. Comparing those linked to sexual function in elderly 40-day-old male flies and sprightly 10-day-old flies, Fu found the older neurones carried 10 times less dopamine. Boosting levels lengthened the time the older flies spent trying to mate. There are obviously big differences between a man's brain and that of a male Drosophila, but Fu says that the new results could provide a useful starting point for in-depth studies that may have clinical implications. For instance, that research might eventually identify ways to fine-tune dopamine levels in humans, perhaps to reverse age-related declines in sexual drive, or even to suppress an overactive libido. We already have therapies for treating male sexual dysfunction – notably the drug viagra. But probing the link between dopamine and sexual dysfunction is still important. For instance, dopamine-replacement therapy is one of the most effective treatments for Parkinson's disease – but the therapy can lead to harmful compulsive sexual behaviour. But Wendi Neckameyer at the Saint Louis University School of Medicine in Missouri isn't sure we should talk about potential implications for men just yet – it's enough to say that the researchers "have begun to tease out an incredibly complex neural circuit", she says. © Copyright Reed Business Information Ltd

Keyword: Sexual Behavior
Link ID: 21115 - Posted: 07.01.2015

Hannah Devlin Science correspondent Two licensed drugs have been shown to halt brain degeneration in mice, raising the prospect of a rapid acceleration in the search for a medicine to beat Alzheimer’s disease. The results, presented on Tuesday at the Alzheimer’s Society annual research conference in Manchester, have been hailed as “hugely promising” because they involve medicines that are already known to be safe and well-tolerated in people – potentially cutting years from the timeline for drugs to reach patients. Speaking ahead of her presentation, Giovanna Mallucci, professor of clinical neuroscience at the University of Cambridge, said: “It’s really exciting. They’re licensed drugs. This means you’d do a straightforward basic clinical trial on a small group of patients because these are not new compounds, they’re known drugs.” The scientists have chosen not to name the two drugs, which are currently used for conditions unrelated to dementia, to avoid the possibility of patients seeking to use them ahead of any clinical trial to prove their efficacy. The findings build on a landmark study two years ago, showing that brain cell death could be halted in mice by switching off a faulty signal in the brain that stops new proteins being produced. However, the breakthrough relied on a compound that had severe physical side-effects including weight loss and diabetes, making it unsuitable for use in humans. The two drugs were identified after Mallucci’s team screened hundreds of licensed compounds in search for something safe that had the same protective effects on the brain. Clare Walton, research manager at the Alzheimer’s Society, said: “The new results are hugely promising because the drugs are already given to people and we know they’re safe.” © 2015 Guardian News and Media Limited

Keyword: Alzheimers
Link ID: 21114 - Posted: 07.01.2015