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By CARL ZIMMER Your body is home to about 100 trillion bacteria and other microbes, collectively known as your microbiome. Naturalists first became aware of our invisible lodgers in the 1600s, but it wasn’t until the past few years that we’ve become really familiar with them. This recent research has given the microbiome a cuddly kind of fame. We’ve come to appreciate how beneficial our microbes are — breaking down our food, fighting off infections and nurturing our immune system. It’s a lovely, invisible garden we should be tending for our own well-being. But in the journal Bioessays, a team of scientists has raised a creepier possibility. Perhaps our menagerie of germs is also influencing our behavior in order to advance its own evolutionary success — giving us cravings for certain foods, for example. “One of the ways we started thinking about this was in a crime-novel perspective,” said Carlo C. Maley, an evolutionary biologist at the University of California, San Francisco, and a co-author of the new paper. “What are the means, motives and opportunity for the microbes to manipulate us? They have all three.” The idea that a simple organism could control a complex animal may sound like science fiction. In fact, there are many well-documented examples of parasites controlling their hosts. Some species of fungi, for example, infiltrate the brains of ants and coax them to climb plants and clamp onto the underside of leaves. The fungi then sprout out of the ants and send spores showering onto uninfected ants below. How parasites control their hosts remains mysterious. But it looks as if they release molecules that directly or indirectly can influence their brains. © 2014 The New York Times Company

Keyword: Obesity; Aggression
Link ID: 19981 - Posted: 08.20.2014

by Bethany Brookshire When a laboratory mouse and a house mouse come nose to nose for the first time, each one is encountering something it has never seen before. They are both Mus musculus. But the wild mouse is facing a larger, fatter, calmer and less aggressive version of itself that’s the result of brother-to-sister inbreeding for generations, resulting in mice that are almost completely genetically identical. Laboratory mice are incredibly valuable tools for research into diseases from Alzheimer’s to Zellweger syndrome. Scientists have a deep understanding of lab mouse DNA, and can use that knowledge to study how specific genes may control certain behaviors and underlie disease. But with all the inbreeding comes some traits that, while desirable in a lab mouse, may not reflect the behavior of an animal in the wild. So for some questions, and some behaviors, scientists might need something a bit wilder. A new study takes lab mice back to their roots and along the way uncovers a new gene function. Lea Chalfin and colleagues at the Weizmann Institute of Science in Rohovot, Israel, bred laboratory mice with wild mice for 10 generations. The result was a mouse with wild mouse genes and wild mouse behavior — with a few important lab mouse genes mixed in. The technique allows scientists to place specific mutations in a wild mouse. The results have interesting implications for studying the mouse species, and might provide some new ways to study human disease as well. Chalfin and her colleagues were especially interested in behaviors linked to female aggression. © Society for Science & the Public 2000 - 2013

Keyword: Aggression; Aggression
Link ID: 19980 - Posted: 08.20.2014

By James Gallagher Health editor, BBC News website Stimulating the part of the brain which controls movement may improve recovery after a stroke, research suggests. Studies showed firing beams of light into the brains of mice led to the animals moving further and faster than those without the therapy. The research, published in Proceedings of the National Academy of Science, could help explain how the brain recovers and lead to new treatments. The Stroke Association said the findings were interesting. Strokes can affect memory, movement and the ability to communicate. Brain cells die when their supply of oxygen and sugars is cut off by a blood clot. Stroke care is focused on rapid treatment to minimise the damage, but some recovery is possible in the following months as the brain rewires itself. The team at Stanford University School of Medicine investigated whether brain stimulation aided recovery in animal experiments. They used a technique called optogenetics to stimulate just the neurons in the motor cortex - the part of the brain responsible for voluntary movements - following a stroke. After seven days of stimulation, mice were able to walk further down a rotating rod than mice which had not had brain stimulation. After 10 days they were also moving faster. The researchers believe the stimulation is affecting how the wiring of the brain changes after a stroke. They detected higher levels of chemicals linked to the formation of new connections between brain cells. Lead researcher Prof Gary Steinberg said it was a struggle to give people drugs to protect brain cells in time as the "time window is very short". BBC © 2014

Keyword: Stroke
Link ID: 19979 - Posted: 08.20.2014

|By Matthew H. Schneps “There are three types of mathematicians, those who can count and those who can’t.” Bad joke? You bet. But what makes this amusing is that the joke is triggered by our perception of a paradox, a breakdown in mathematical logic that activates regions of the brain located in the right prefrontal cortex. These regions are sensitive to the perception of causality and alert us to situations that are suspect or fishy — possible sources of danger where a situation just doesn’t seem to add up. Many of the famous etchings by the artist M.C. Escher activate a similar response because they depict scenes that violate causality. His famous “Waterfall” shows a water wheel powered by water pouring down from a wooden flume. The water turns the wheel, and is redirected uphill back to the mouth of the flume, where it can once again pour over the wheel, in an endless cycle. The drawing shows us a situation that violates pretty much every law of physics on the books, and our brain perceives this logical oddity as amusing — a visual joke. The trick that makes Escher’s drawings intriguing is a geometric construction psychologists refer to as an “impossible figure,” a line-form suggesting a three-dimensional object that could never exist in our experience. Psychologists, including a team led by Catya von Károlyi of the University of Wisconsin-Eau Claire, have used such figures to study human cognition. When the team asked people to pick out impossible figures from similarly drawn illustrations that did not violate causality, they were surprised to discover that some people were faster at this than others. And most surprising of all, among those who were the fastest were those with dyslexia. © 2014 Scientific American

Keyword: Dyslexia; Aggression
Link ID: 19978 - Posted: 08.20.2014

By James Gallagher Health editor, BBC News website Breastfeeding can halve the risk of post-natal depression, according to a large study of 14,000 new mothers. However, there is a large increase in the risk of depression in women planning to breastfeed who are then unable to do so. The study, published in the journal Maternal and Child Health, called for more support for women unable to breastfeed. A parenting charity said mental health was a "huge issue" for many mothers. The health benefits of breastfeeding to the baby are clear-cut and the World Health Organization recommends feeding a child nothing but breast milk for the first six months. However, researchers at the University of Cambridge said the impact on the mother was not as clearly understood. 'Highest risk' One in 10 women will develop depression after the birth of their child. The researchers analysed data from 13,998 births in the south-west of England. It showed that, out of women who were planning to breastfeed, there was a 50% reduction in the risk of post-natal depression if they started breastfeeding. But the risk of depression more than doubled among women who wanted to, but were not able to, breastfeed. Dr Maria Iacovou, one of the researchers, told the BBC: "Breastfeeding does appear to have a protective effect, but there's the other side of the coin as well. "Those who wanted to and didn't end up breastfeeding had the highest risk of all the groups." BBC © 2014

Keyword: Depression; Aggression
Link ID: 19977 - Posted: 08.20.2014

By TARA PARKER-POPE When the antidrug educator Tim Ryan talks to students, he often asks them what they know about marijuana. “It’s a plant,” is a common response. But more recently, the answer has changed. Now they reply, “It’s legal in Colorado.” These are confusing times for middle and high school students, who for most of their young lives have been lectured about the perils of substance abuse, particularly marijuana. Now it seems that the adults in their lives have done an about-face. Recreational marijuana is legal in Colorado and in Washington, and many other states have approved it for medical use. Lawmakers, the news media and even parents are debating the merits of full-scale legalization. “They are growing up in a generation where marijuana used to be bad, and maybe now it’s not bad,” said Mr. Ryan, a senior prevention specialist with FCD Educational Services, an antidrug group that works with students in the classroom. “Their parents are telling them not to do it, but they may be supporting legalization of it at the same time.” Antidrug advocates say efforts to legalize marijuana have created new challenges as they work to educate teenagers and their parents about the unique risks that alcohol, marijuana and other drugs pose to the developing teenage brain. These educators say their goal is not to vilify marijuana or take a stand on legalization; instead, they say their role is to convince young people and their parents that the use of drugs is not just a moral or legal issue, but a significant health issue. “The health risks are real,” said Steve Pasierb, the chief executive of the Partnership for Drug-Free Kids. “Every passing year, science unearths more health risks about why any form of substance use is unhealthy for young people.” © 2014 The New York Times Company

Keyword: Drug Abuse; Aggression
Link ID: 19976 - Posted: 08.19.2014

Claudia M. Gold When I hear debate over the association between SSRI’s (selective serotonin re-uptake inhibitors, a class of antidepressant medication) and suicidal behavior in children and adolescents, I am immediately brought back to a night in the early 2000's. As the covering pediatrician I was called to the emergency room to see a young man, a patient of a pediatrician in a neighboring town, who had attempted suicide by taking a nearly lethal overdose. That night, as I watched over him in the intensive care unit, I learned that he was a high achieving student and athlete who, struggling under the pressures of the college application process, had been prescribed an SSRI by his pediatrician. His parents described a transformation in his personality over the months preceding the suicide attempt that was so dramatic that I ordered a CT scan to see if he had a brain tumor. It was normal. When, in the coming years the data emerged about increasing suicidal behavior following use of SSRI's, I recognized in retrospect that his change in behavior was a result of the medication. But at the time I knew nothing of these serious side effects. At that time, coinciding with pharmaceutical industry's aggressive marketing campaign directed at the public as well as a professional audience, these drugs were becoming increasingly popular with pediatricians. As the possible serious side effects of these medications came increasingly in to awareness, the FDA issued the controversial "black box warning" that the drugs carried an increased risk of suicidal behavior. Following the black box warning, pediatricians, myself included, became reluctant to prescribe these medications. We did not have the time or experience to provide the recommended increased monitoring and close follow-up.

Keyword: Depression; Aggression
Link ID: 19975 - Posted: 08.19.2014

by Clare Wilson Figuring out how the brain works is enough to make your head spin. But now we seem to have a handle on how it gets its folded shape. The surface layer of the brain, or cortex, is also referred to as our grey matter. Mammals with larger brains have a more folded cortex, and the human brain is the most wrinkled of all, cramming as much grey matter into our skulls as possible. L. Mahadevan at Harvard University and his colleagues physically modelled how the brain develops in the embryo, using a layer of gel to stand in for the grey matter. This gel adhered to the top of a solid hemisphere of gel representing the white matter beneath. In the embryo, grey matter grows as neurons are created or others migrate to the cortex from the brain's centre. By adding a solvent to make the grey matter gel expand, the team mimicked how the cortex might grow in the developing brain. They didn't model what effect, if any, the skull would have had. Hills and valleys The team varied factors such as the stiffness of the gels and the depth of the upper layer to find a combination that led to similarly shaped wrinkles as those of the human brain, with smooth "hills" and sharply cusped "valleys". There are several theories about how the brain's folds form. These include the possibility that more neurons migrate to the hills, making them rise above the valleys, or that the valleys are pulled down by the axons – fibres that connect neurons to each other – linking highly interconnected parts of the brain together. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain
Link ID: 19974 - Posted: 08.19.2014

Sara Reardon The National Science Foundation (NSF)’s role in the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative is starting to take shape. On 18 August, the NSF awarded 36 small grants totalling US$10.8 million to projects studying everything from electrodes that measure chemical and electronic signals to artificial intelligence programs to identify brain structures. The three agencies participating in the BRAIN Initiative have taken markedly different approaches. The Defense Advanced Research Projects Agency, which received $50 million this year for the neuroscience programme, is concentrating on prosthetics and treatments for brain disorders that affect veterans, such as post-traumatic stress disorder. It has already awarded multi-million dollar grants to several teams. The National Institutes of Health, which received $40 million this year, has put together a 146-page plan to map and observe the brain over the next decade, and will announce its first round of grant recipients next month. The NSF, by contrast, has cast a wider net. The agency sent an request in March for informal, two-page project ideas. The only criterion was that the projects somehow address the properties of neural circuits. The response was overwhelming, says James Deshler, deputy director of the NSF’s Division of Biological Infrastructure. The agency had expected to fund about 12 grants, but decided to triple that number after receiving nearly 600 applications. “People started finding money in different pockets,” Deshler says. The wide-ranging list of winning projects includes mathematical models that help computers recognize different parts and patterns in the brain, physical tools such as new types of electrodes, and other tools that integrate and link neural activity to behaviour. © 2014 Nature Publishing Group

Keyword: Development of the Brain; Aggression
Link ID: 19973 - Posted: 08.19.2014

|By Karen Hopkin They say that the nose knows. But it still gets its marching orders from the brain—at least when it comes to the lungs. Got that? Nose to brain to lungs. Because a new study shows that when people with asthma think they’re smelling something noxious, their airways become inflamed—even when the odor is harmless. The finding is in the Journal of Psychosomatic Research. [Cristina Jaén and Pamela Dalton, Asthma and odors: The role of risk perception in asthma exacerbation] Asthma attacks can be triggered by pollen, dust, harsh chemicals or scents. These environmental annoyances constrict the airways in the lung, making breathing difficult. In this study, researchers wanted to see whether an individual’s assumptions have any influence over this breathtaking series of events. So they exposed 17 asthma sufferers to a benign chemical that smells like roses for 15 minutes. Nine subjects were told the fragrance was a potential irritant, the other eight that it would be therapeutic. The results were as plain as the nose on your face: subjects who expected an irritant experienced inflammation. And those who were primed to be soothed had no adverse reactions—even if they were normally bothered by perfumes. The results suggest that a rose by any other name would smell as sweet. Or be as irritating as you expect it will. © 2014 Scientific American

Keyword: Chemical Senses (Smell & Taste)
Link ID: 19972 - Posted: 08.19.2014

Helen Shen For most adults, adding small numbers requires little effort, but for some children, it can take all ten fingers and a lot of time. Research published online on 17 August in Nature Neuroscience1 suggests that changes in the hippocampus — a brain area associated with memory formation — could help to explain how children eventually pick up efficient strategies for mathematics, and why some children learn more quickly than others. Vinod Menon, a developmental cognitive neuroscientist at Stanford University in California, and his colleagues presented single-digit addition problems to 28 children aged 7–9, as well as to 20 adolescents aged 14–17 and 20 young adults. Consistent with previous psychology studies2, the children relied heavily on counting out the sums, whereas adolescents and adults tended to draw on memorized information to calculate the answers. The researchers saw this developmental change begin to unfold when they tested the same children at two time points, about one year apart. As the children aged, they began to move away from counting on fingers towards memory-based strategies, as measured by their own accounts and by decreased lip and finger movements during the task. Using functional magnetic resonance imaging (fMRI) to scan the children's brains, the team observed increased activation of the hippocampus between the first and second time point. Neural activation decreased in parts of the prefrontal and parietal cortices known to be involved in counting, suggesting that the same calculations had begun to engage different neural circuits. © 2014 Nature Publishing Group

Keyword: Development of the Brain; Aggression
Link ID: 19971 - Posted: 08.18.2014

Vaughan Bell For thousands of years, direct studies of the human brain required the dead. The main method of study was dissection, which needed, rather inconveniently for the owner, physical access to their brain. Despite occasional unfortunate cases where the living brain was exposed on the battlefield or the surgeon's table, corpses and preserved brains were the source of most of our knowledge. When brain scanning technologies were invented in the 20th century they allowed the structure and function of the brain to be shown in living humans for the first time. This was as important for neuroscientists as the invention of the telescope and the cadaver slowly faded into the background of brain research. But recently, scrutiny of the post-mortem brain has seen something of a revival, a resurrection you might say, as modern researchers have become increasingly interested in applying their new scanning technologies to the brains of the deceased. Forensic pathologists have the job of working out the cause and manner of death to present as legal evidence and have been partly responsible for this curious full circle. One of their main jobs is the autopsy, where the pathologist examines the body, inside and out, to assess its condition at the point of death. Although the traditional autopsy has many advantages, not least the microscopic examination of body tissue, there are drawbacks. One is that within some religions cutting up the dead body is seen as an infringement of human dignity and may delay burial beyond the customary period. The other is that an autopsy is a one-shot deal. If someone disagrees with the way it has been carried out or its interpretation, it is usually too late to do anything except re-examine photos or, on the rare occasions when they may have been kept, tissue samples. © 2014 Guardian News and Media Limited

Keyword: Brain imaging
Link ID: 19970 - Posted: 08.18.2014

by Andy Coghlan Pioneering studies of post-mortem brain tissues have yielded the first evidence of a potential association between Alzheimer's disease and the epigenetic alteration of gene function. The researchers stress, however, that more research is needed to find out if the changes play a causal role in the disease or occur as a result of it. We already have some evidence that the risk of developing Alzheimer's might be elevated by poor diet, lack of exercise, and inflammatory conditions such as diabetes, obesity and clogging of blood vessels with fatty deposits. The new research hints that the lifestyle changes that raise Alzheimer's risk may be taking effect through epigenetic changes. The idea is strengthened by the fact that the brain tissue samples studied in the new work came from hundreds of people, many of whom had Alzheimer's when they died, and that a number of genes identified were found by two teams working independently, one in the UK and one in the US. "The results are compelling and consistent across four cohorts of patients taken across the two studies," says Jonathan Mill at the University of Exeter, who led the UK-based team. "It's illuminated new genetic pathways affecting the disease and, given the lack of success tackling Alzheimer's so far, new leads are going to be vital." "We can now focus our efforts on understanding how these genes are associated with the disease," says Philip De Jager of the Brigham and Women's Hospital in Boston, who headed the US team. © Copyright Reed Business Information Ltd.

Keyword: Alzheimers; Aggression
Link ID: 19969 - Posted: 08.18.2014

By Victoria Gill Science reporter, BBC News Scientists in Brazil have managed to eavesdrop on underwater "turtle talk". Their recordings have revealed that, in the nesting season, river turtles appear to exchange information vocally - communicating with each other using at least six different sounds. This included chatter recorded between females and hatchlings. The researchers say this is the first record of parental care in turtles. It shows they could be vulnerable to the effects of noise pollution, they warn. The results, published recently in the Journal Herpetologica, include recordings of the strange turtle talk. They reveal that the animals may lead much more socially complex lives than previously thought. The team, including researchers from the Wildlife Conservation Society (WCS) and the National Institute of Amazonian Research carried out their study on the Rio Trombetas in the Amazon between 2009 and 2011. They used microphones and underwater hydrophones to record more than 250 individual sounds from the animals. The scientists then analysed these vocalisations and divided them into six different types, correlating each category with a specific behaviour. Dr Camila Ferrara, of the WCS Brazil programme, told BBC News: "The [exact] meanings aren't clear... but we think they're exchanging information. "We think sound helps the animals to synchronise their activities in the nesting season," she said. The noises the animals made were subtly different depending on their behaviour. For example, there was a specific sound when adults were migrating through the river, and another when they gathered in front of nesting beaches. There was a different sound again made by adults when they were waiting on the beaches for the arrival of their hatchlings. BBC © 2014

Keyword: Animal Communication; Aggression
Link ID: 19968 - Posted: 08.18.2014

|By Christie Nicholson Children who experience neglect, abuse and poverty have a tougher time as adults than do well-cared-for kids. Now there’s evidence that such stress can actually change the size of brain structures responsible for learning, memory and processing emotion. The finding is in the journal Biological Psychiatry. [Jamie L. Hanson et al, Behavioral Problems After Early Life Stress: Contributions of the Hippocampus and Amygdala] Researchers took images of the brains of 12-year-olds who had suffered either physical abuse or neglect or had grown up poor. From the images the scientists were able to measure the size of the amygdala and hippocampus—two structures involved in emotional processing and memory. And they compared the sizes of these structures with those of 12-year-old children who were raised in middle-class families and had not been abused. And they found that the stressed children had significantly smaller amygdalas and hippocampuses than did the kids from the more nurturing environments. Early stress has been associated with depression, anxiety, cancer and lack of career success later on in adulthood. This study on the sizes of brain regions may offer physiological clues to why what happens to toddlers can have such a profound impact decades later. © 2014 Scientific American

Keyword: Stress; Aggression
Link ID: 19967 - Posted: 08.18.2014

Ian Sample, science editor Scientists have prevented muscle wastage in mice with a form of muscular dystrophy by editing the faulty gene that causes the disease. The radical procedure could not be performed in humans, but researchers believe the work raises hopes for future gene-editing therapies to stop the disease from progressing in people. Duchenne muscular dystrophy is caused by mutations in a gene on the X chromosome and affects around one in 3,500 boys. Because girls have two X chromosomes they tend not to be affected, but can be carriers of the disease. The pivotal gene is used to make a protein called dystrophin which is crucial for muscle fibre strength. Without the protein, muscles in the body, including the heart and skeletal muscles, weaken and waste away. Most patients die by the age of 25 from breathing or heart problems. Researchers in the US used a powerful new gene-editing procedure called CRISPR to correct mutations in the dystrophin gene in mice that were destined to develop the disease. They extracted mouse embryos from their mothers and injected them with the CRISPR biological machinery, which found and corrected the faulty gene. After the injections, the mouse embryos were reimplanted in females and carried to term. Tests on the mice found that the therapy helped to restore levels of dystrophin, and that their skeletal muscle performed normally, even when only 17% of their cells contained corrected genes. The procedure could not be done in humans, but the proof-of-principle experiment demonstrates that correcting only a small proportion of cells could lead to a dramatic improvement for patients. © 2014 Guardian News and Media Limited

Keyword: Movement Disorders; Aggression
Link ID: 19966 - Posted: 08.16.2014

Ever wonder why it’s hard to focus after a bad night’s sleep? Using mice and flashes of light, scientists show that just a few nerve cells in the brain may control the switch between internal thoughts and external distractions. The study, partly funded by the National Institutes of Health, may be a breakthrough in understanding how a critical part of the brain, called the thalamic reticular nucleus (TRN), influences consciousness. “Now we may have a handle on how this tiny part of the brain exerts tremendous control over our thoughts and perceptions,” said Michael Halassa, M.D., Ph.D., assistant professor at New York University’s Langone Medical Center and a lead investigator of the study. “These results may be a gateway into understanding the circuitry that underlies neuropsychiatric disorders.” The TRN is a thin layer of nerve cells on the surface of the thalamus, a center located deep inside the brain that relays information from the body to the cerebral cortex. The cortex is the outer, multi-folded layer of the brain that controls numerous functions, including one’s thoughts, movements, language, emotions, memories, and visual perceptions. TRN cells are thought to act as switchboard operators that control the flow of information relayed from the thalamus to the cortex. To understand how the switches may work, Dr. Halassa and his colleagues studied the firing patterns of TRN cells in mice during sleep and arousal, two states with very different information processing needs. The results published in Cell, suggest that the TRN has many switchboard operators, each dedicated to controlling specific lines of communication. Using this information, the researchers could alter the attention span of mice.

Keyword: Sleep; Aggression
Link ID: 19965 - Posted: 08.16.2014

By Rachel Feltman At every waking moment, your brain is juggling two very different sets of information. Input from the world around you, like sights and smells, has to be processed. But so does internal information — your memories and thoughts. Right now, for example, I’m looking at a peach: It’s yellow and pink, and has a lot of fuzz. But I also know that it smells nice (a personal assessment) and I’m imagining how good it will taste, based on my previous experience with fragrant pink fruits. The brain’s ability to handle these different signals is key to cognitive function. In some disorders, particularly autism and schizophrenia, this ability is disrupted. The brain has difficulty keeping internal and external input straight. In a new study published Thursday in Cell, researchers observe the switching method in action for the first time. While the research used mice, not humans, principal investigator and NYU Langone Medical Center assistant professor Michael Halassa sees this as a huge step toward understanding and manipulating the same functions in humans. “This is one of the few moments in my life where I’d actually say yes, absolutely this is going to translate to humans,” Halassa said. “This isn’t something based on genes or molecules that are specific to one organism. The underlying principles of how the brain circuitry works are likely to be very similar in humans and mice.” That circuitry has been hypothesized for decades. Neurologists know that the cortex of the brain is responsible for higher cognitive functions, like music and language. And the thalamus, which is an egg-like structure in the center of the brain, works to direct the flow of internal and external information before it gets to the cortex.

Keyword: Autism; Aggression
Link ID: 19964 - Posted: 08.16.2014

by Bethany Brookshire The clearish lump looks like some bizarre, translucent gummy candy that might have once been piña colada flavored. But this is something you definitely don’t want to eat. That see-through blob was once a mouse. In the Aug. 14 Cell, scientists at Caltech detail the difficult series of methods required to make small animals such as mice and rats completely translucent. Scientists have been trying to clear tissue for better observation since the 1800s, and, as with all science, the new techniques build on many previous experiments done in a variety of labs. The techniques make it possible to capture images both beautiful and gross. And the procedure will teach scientists more about anatomy than ever before. If you want to render an animal transparent, you first have to overcome a solid problem: lipids. This group includes molecules essential to life, such as fats, cholesterols, waxes and steroids. Lipids form the membranes that surround our cells, the hormones that make us grow and reproduce and much, much more. But lipids have a problem. You can’t see through them. So to render an organism transparent, you need to remove the lipids. Bin Yang and colleagues in Viviana Gradinaru’s lab at Caltech used detergents to dissolve the lipids. The technique is based on CLARITY, a method that Gradinaru helped to develop in Karl Deisseroth’s lab at Stanford. Scientists there rendered a mouse brain transparent using CLARITY. Gradinaru explains that for a clear organ, dissolving lipids alone alone isn’t enough. “Without lipids the tissue would just collapse, so we need to maintain the structure of the tissue,” she says. © Society for Science & the Public 2000 - 2013

Keyword: Brain imaging
Link ID: 19963 - Posted: 08.16.2014

By Kate Yandell Researchers have accumulated detailed knowledge of the neurons that drive male fruit flies’ mating behaviors. But the neurons that prompt females to respond—or not—to male overtures have been less-studied. Three papers published today (July 2) in Neuron and Current Biology begin to change that. They identify sets of neurons in female fruit flies that help process mating signals, modulate the insects’ receptivity to male courtship, and drive mating behavior. “These three groups independently identified important neuronal groups [that] are positioned in different points in the neuronal circuitry for regulating female receptivity,” said Daisuke Yamamoto, a behavioral geneticist at Tohoku University in Japan who was not involved in any of the studies. “We’ve had access to the male circuitry for a while now, and that’s turning out to be a really interesting way to study how behavior works,” said Jennifer Bussell, whose work as a PhD student at Rockefeller University contributed to the Current Biology paper. “Having that complementary circuit in the female can only provide more fodder for interesting experiments.” Female fruit flies’ mating behaviors depend on their reproductive state. They become receptive to mating as they mature, but become less receptive to males’ advances immediately after mating. If a female fruit fly is receptive to mating, she responds to male pheromones and courtship songs by engaging in a behavior called pausing, where she stops in her tracks near males so they can mount her and she opens her vaginal plates—hard coverings that protect her reproductive tract. © 1986-2014 The Scientist

Keyword: Sexual Behavior
Link ID: 19962 - Posted: 08.16.2014