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Someday, a smart phone app that asks what you’re feeling 10 times a day may be able to tell you if you’re edging closer to depression—and recommend that you seek preventive therapy or drugs. Scientists have discovered that how quickly someone bounces back from negative feelings, over hours or days, can predict whether that person is at risk of an episode of major depressive disorder. “The holy grail of depression epidemiology is that we want to intervene early to prevent people from having depressive episodes,” says social scientist Stephen Gilman of Harvard University, who was not involved in the study. “Where this work is headed is making an advance in that direction, toward early detection and therefore early intervention.” Researchers asked more than 600 people—some healthy and some with a diagnosis of depression—to track their emotions for 5 or 6 days. Ten times a day, at random intervals, a watch would beep and the subjects would record how strongly they identified with each of four emotions: cheerful, content, sad, and anxious. Six to 8 weeks later, participants filled out a more detailed questionnaire that rated their levels of clinical depression. By the end of the follow-up period, about 13% of the subjects had experienced a shift toward being more depressed, a number consistent with what would be expected in the general population. Trends in the daily mood records, the team discovered, could predict whether a previously healthy person would make that shift toward depression. © 2013 American Association for the Advancement of Science
Link ID: 19015 - Posted: 12.10.2013
By JAMES GORMAN Sometimes the scientists who study animal behavior solve puzzles and other times they uncover new ones. The war between mockingbirds and cowbirds is a case in point. Cowbirds are brood parasites, meaning they lay their eggs in the nests of other bird species, thus unloading the messy and demanding business of chick-rearing. They also peck holes in the eggs of the host birds, destroying as many as they can. Mockingbirds are a favorite target of this plan, and it seems to make perfect sense for them to viciously attack cowbirds when they catch them in the nest. But when Ros Gloag, then a doctoral student at Oxford, and her colleagues in Argentina looked closely at the war between chalk-browed mockingbirds and shiny cowbirds, they found something unexpected, as they reported in the November issue of Animal Behaviour. They stationed small video cameras near the nests of 40 pairs of chalk-browed mockingbirds. Over two breeding seasons they recorded more than 200 attacks on intruding cowbirds. They were surprised to find that these attacks, which their videos show to be quite vicious, did not stop the cowbirds from laying eggs. The cowbirds would hunker down and let the much large mockingbirds deliver hammer blows to the head, but in matter of seconds they would lay an egg and flee. How could such a failed strategy persist in evolution? © 2013 The New York Times Company
Brian Owens Fruitflies know exactly how much alcohol will be good for their young. Larvae living on a food source with the right concentration of ethanol will grow into heavy, healthy adults and will be protected against parasites — which explains why the insects are attracted to rotting fruit or the crate of empty beer bottles in your kitchen but not to the vodka or gin. Now researchers have uncovered the neural mechanism that allows the fruitfly Drosophila melanogaster to choose the best place to lay its eggs. The work is published today in Proceedings of the National Academy of Sciences1. A team led by Ulrike Heberlein, a molecular biologist at the Howard Hughes Medical Institute’s Janelia Farm Research Campus in Ashburn, Virginia, found that clusters of neurons, working in opposition to each other, help the flies to choose the place with the most beneficial concentration of ethanol in which to lay their eggs. The neurons all release the neurotransmitter dopamine, a key player in the brain's reward circuitry. Neurons of the PAM and PPM3 clusters encourage the flies to seek out ethanol, whereas PPL1 neurons apply the brakes, preventing the flies from laying their eggs on food containing high levels of ethanol that could harm the larvae. “They can discriminate among ethanol concentrations that are very similar — 3% versus 5% — so the system evolved to have great sensitivity,” says Heberlein. Their favourite booze strength is 5%, similar to that of a typical beer. Heberlein's team also traced the neurons involved in ethanol preference to specific brain regions. Both the pro-ethanol PAM and anti-ethanol PPL1 neurons were active in the mushroom body, whereas the pro-ethanol PPM3 ones were active in the ellipsoid body. Both of these brain structures are involved in decision-making and memory, and mushroom body neurons also play a part in ethanol-reward memory. © 2013 Nature Publishing Group,
Keyword: Chemical Senses (Smell & Taste)
Link ID: 19013 - Posted: 12.10.2013
Researchers striving to understand the origins of dementia are building the case against a possible culprit: lead exposure early in life. A study spanning 23 years has now revealed that monkeys who drank a lead-rich formula as infants later developed tangles of a key brain protein, called tau, linked to Alzheimer's disease. Though neuroscientists say more work is needed to confirm the connection, the research suggests that people exposed to lead as children—as many in America used to be before it was eliminated from paint, car emissions, water, and soil—could have an increased risk of the common, late-onset form of Alzheimer’s disease. Even in small doses, lead can wreak havoc on the heart, intestines, kidneys, and nervous system. Children are especially prone to its pernicious effects, as it curbs brain development. Many studies have linked early lead exposure with lower IQs. Researchers estimate that one in 38 children in the United States still have harmful levels of the metal in their systems, but evidence linking this exposure to dementia later in life has been tenuous. A team led by toxicologist Nasser Zawia, however, has vigorously pursued the lead hypothesis. In one early study, from 2008, the group showed that plaques, insoluble globs of a protein called β-amyloid, marred the brains of five macaques that had consumed a lead-enriched formula as infants. The researchers had compared the preserved brain tissues from those macaques, sacrificed in 2003 at age 23 in a National Institutes of Health lab, with four similarly aged monkeys who had had lead-free formula. The amyloid plaques closely resembled those in the brains of adults with Alzheimer's disease that are thought to contribute to the dementia. © 2013 American Association for the Advancement of Science.
By Sandra Steingard, What does it mean that the man who killed 12 people at the Washington Naval Yard had told people that he was “hearing voices”? I have spent 30 years as a psychiatrist treating people who are psychotic. Almost every day I meet with individuals who hear voices that no one else hears, are sure the TV or radio is talking to them or have such confused thinking that it is hard to understand what they are trying to tell me. Sometimes these patients lead quiet lives. But not uncommonly these voices get them into trouble. I’ve had patients who call the police repeatedly, demanding that they stop bugging their phone. And others who stay up all night talking back at the voices. Some accuse family members of being involved in the torment. In many cases, this is a frightening experience — for the people I see and those who love them. And the labels we use — “schizophrenia,” “bipolar disorder,” “psychosis” — only crudely capture these experiences. About 60 years ago, a group of drugs was discovered that appeared to quiet the voices, improve the clarity of thought and lessen the preoccupation with delusion beliefs. Originally called major tranquilizers and later renamed antipsychotic drugs, these have been considered essential for the treatment of people with schizophrenia. Once it was clear that these drugs were helpful in the short term, questions arose over how long people should remain on them. Studies done in the 1970s and 1980s looked at people who were stabilized after being treated with antipsychotic drugs for several months and then followed them for up to two years. Some continued on the drugs, while others stopped taking them. The relapse rate was much higher in the group that stopped the medications. Based on these studies, treatment guidelines now state that people should stay on anti-psychotics indefinitely. The problem with “indefinitely” is that antipsychotic drugs have many troubling side effects. © 1996-2013 The Washington Post
Link ID: 19011 - Posted: 12.10.2013
There is more than meets the eye following even a mild traumatic brain injury. While the brain may appear to be intact, new findings reported in Nature suggest that the brain’s protective coverings may feel the brunt of the impact. Using a newly developed mouse trauma model, senior author Dorian McGavern, Ph.D., scientist at the National Institute of Neurological Disorders and Stroke (NINDS), part of the National Institutes of Health, watched specific cells mount an immune response to the injury and try to prevent more widespread damage. Notably, additional findings suggest a similar immune response may occur in patients with mild head injury. In this study, researchers also discovered that certain molecules, when applied directly to the mouse skull, can bypass the brain’s protective barriers and enter the brain. The findings suggested that, in the mouse trauma model, one of those molecules may reduce effects of brain injury. Although concussions are common, not much is known about the effects of this type of damage. As part of this study, Lawrence Latour, Ph.D., a scientist from NINDS and the Center for Neuroscience and Regenerative Medicine, examined individuals who had recently suffered a concussion but whose initial scans did not reveal any physical damage to brain tissue. After administering a commonly used dye during MRI scans, Latour and his colleagues saw it leaking into the meninges, the outer covers of the brain, in 49 percent of 142 patients with concussion. To determine what happens following this mild type of injury, researchers in Dr. McGavern’s lab developed a new model of brain trauma in mice.
Keyword: Brain Injury/Concussion
Link ID: 19010 - Posted: 12.10.2013
Many physicians and parents report that their autistic children have unusually severe gastrointestinal problems, such as chronic constipation or diarrhea. These observations have led some researchers to speculate that an ailing gut contributes to the disorder in some cases, but scientific data has been lacking. Now, a provocative study claims that a probiotic treatment for gastrointestinal issues can reduce autismlike symptoms in mice and suggests that this treatment could work for humans, too. The reported incidence of gut maladies in people with autism varies wildly between published studies—from zero to more than 80%—making it difficult to establish just how commonly the two conditions go together, says principal investigator Sarkis Mazmanian, a microbiologist at the California Institute of Technology (Caltech) in Pasadena. Overall, however, the evidence seems to point toward a connection. Last year, for example, a Centers for Disease Control and Prevention study of thousands of children with developmental disabilities found that kids with autism were twice as likely as children with other types of disorders to have frequent diarrhea or colitis, an inflammation of the large intestine. For many years, Mazmanian and his and colleagues have been studying the effects of a nontoxic strain of the bacterium Bacteroides fragilis on diseases such as Crohn's disease, which causes intestinal inflammation and allows potentially harmful substances that should pass out of the body to leak through junctions between cells that are normally tight. Although the researchers don’t understand the mechanism, the bacterium appears to restore the damaged gut, possibly by helping close these gaps. © 2013 American Association for the Advancement of Science.
Link ID: 19009 - Posted: 12.06.2013
By Dana Smith Daniel Tammet has memorized Pi to the 22,514th digit. He speaks ten different languages, including one of his own invention, and he can multiply enormous sums in his head within a matter of seconds. However, he is unable to hold down a standard 9-to-5 job, in part due to his obsessive adherence to ritual, down to the precise times he has his tea every day. Daniel is a savant. He is also autistic. And he is a synesthete. Daniel experiences numbers as having color, as well as shape and texture. This helps him perform amazing mathematical feats seemingly without effort, the answer simply materializing to him rather than having to calculate it out. In an interview he gave with The Guardian, Daniel explained, “When I multiply numbers together, I see two shapes. The image starts to change and evolve, and a third shape emerges. That’s the answer. It’s mental imagery. It’s like maths without having to think.” Clearly this man has an extraordinary brain. However, Daniel is perhaps not entirely unique, and it appears that the link between autism and synesthesia is more common than originally thought. This suggests that there is a potential common mechanism between these two conditions, which may even help to explain some of Daniel’s special savant abilities. A new study published in the journal Molecular Autism from a team of researchers at the University of Cambridge now empirically shows that there is an almost three-fold higher occurrence of synesthesia in individuals with autism (18.9%), compared with that of the general population (7.2%). This increased prevalence implies that there is indeed a significant link between autism and synesthesia. © 2013 Scientific American
Link ID: 19008 - Posted: 12.06.2013
Helen Shen Dyslexia may be caused by impaired connections between auditory and speech centres of the brain, according to a study published today in Science1. The research could help to resolve conflicting theories about the root causes of the disorder, and lead to targeted interventions. When people learn to read, their brains make connections between written symbols and components of spoken words. But people with dyslexia seem to have difficulty identifying and manipulating the speech sounds to be linked to written symbols. Researchers have long debated whether the underlying representations of these sounds are disrupted in the dyslexic brain, or whether they are intact but language-processing centres are simply unable to access them properly. A team led by Bart Boets, a clinical psychologist at the Catholic University of Leuven in Belgium, analysed brain scans and found that phonetic representations of language remain intact in adults with dyslexia, but may be less accessible than in controls because of deficits in brain connectivity. "The authors took a really inventive and thoughtful approach," says John Gabrieli, a neuroscientist at the Massachusetts Institute of Technology in Cambridge, Massachusetts. "They got a pretty clear answer." Communication channels Boets and his team used a technique called multivoxel pattern analysis to study fine-scale brain signals as people listened to a battery of linguistic fragments such as 'ba' and 'da'. To the researchers' surprise, neural activity in the primary and secondary auditory cortices of participants with dyslexia showed consistently distinct signals for different sounds. © 2013 Nature Publishing Group
by Bob Holmes Perseverance in the face of adversity is an admirable character trait – now it turns out you can conjure it up with a quick zap to a tiny spot in the brain. The discovery in two people with epilepsy was accidental but it is the first to show that simple brain stimulation can create rich, complex alterations of consciousness. Josef Parvizi, a neurologist at Stanford University in California, and his colleagues had implanted electrodes in the brains of two people with epilepsy to help identify the source of their seizures. In the course of their work, they noticed that an odd thing happened when they stimulated a region in the anterior midcingulate cortex – a part of the limbic system involved in emotion, processing, learning and memory. Both patients reported feeling a sense of foreboding, coupled with a determination to overcome whatever challenge they were about to face. During the stimulation, one patient reported feeling "worried that something bad is going to happen" but also noted that "it made me stronger". The other said he felt as if he were figuring out how to get through something. He likened it to driving your car when one of the tires bursts. You're only halfway to your destination and you have no option but to keep going forward. "You're like… am I gonna get through this?" he said (see video). He also reported a sense of urgency: "It was more of a positive thing like… push harder, push harder, push harder to try and get through this." One singular sensation In contrast, when the researchers applied a sham stimulation – going through exactly the same procedure, but with the current set to zero – neither volunteer reported feeling any specific sensations. Stimulation of other nearby regions of the brain less than 5 millimetres away also failed to produce the feelings of either foreboding or perseverance. © Copyright Reed Business Information Ltd.
By Julia Calderone As we sat in my car outside a silent movie theater in Los Angeles, my friend anxiously opened a plastic bag containing a white T-shirt she’d slept in for the past three nights. “Does it smell like me?” she asked nervously, gesturing the open end toward my face. I stuck my nose into the bag and inhaled. We were about to attend a pheromone-based speed dating party with the following rules: 1. Find a clean white T-shirt. 2. Sleep in only that shirt for three consecutive nights. 3. Bring the shirt to the party sealed in a bag. As we walked into the theater, coordinators assigned each of our bags a unique color-coded sticker (pink for female, blue for male), and tossed them into a pile. A pack of hipsters nursing PBRs sat in the wooden theater seats, slightly amused by the bizarre 70s Egyptian-themed silent porn projected onto the screen. In the courtyard, 20-somethings mingled by the outdoor bar. Did they think alcohol would make us okay with sniffing strangers’ dirty laundry? Mounds of bags sat on two long tables – beckoning our nostrils. We were instructed to sniff as many T-shirts of the sex we were attracted to, and select shirts that innately smelled the sexiest. I came across bag number 166, which shockingly smelled exactly like my grandmother’s house – a delightful mix of Christmas and chicken parmesan. The point was to trust our instincts, right? I went with it. © 2013 Scientific American
By NICHOLAS BAKALAR A high body mass and a large waist are both associated with self-reported hearing loss, a new study has found. Researchers used data from a 20-year prospective study of 68,421 women who were25 to 42 years old at the start. After controlling for age, smoking, diabetes, hypertension and other factors, they found that the higher the body mass index, the greater the risk for hearing loss. Compared with women with a B.M.I. under 25, those with an index of 25 to 29 had an 8 percent increased risk. The numbers kept going up in tandem: 11 percent for 30 to 34, 16 percent for 35 to 39 and 19 percent for those above 40. The increasing risk associated with larger waist circumference followed a similar pattern. The study, published in the December issue of The American Journal of Medicine, found that moderate physical activity — as little as four hours of walking a week — also reduced the risk for hearing loss. Researchers found no further advantage in more vigorous exercise. The lead author, Dr. Sharon G. Curhan, a clinical researcher at Brigham and Women’s Hospital in Boston, suggested that obesity might compromise blood flow to the inner ear, and that exercise might improve it, which could explain the associations. “Hearing loss may not be an inevitable part of growing older,” she said. “There may be things we can do to prevent it.” Copyright 2013 The New York Times Company
By Helen Briggs BBC News An anti-tuberculosis vaccine could prevent multiple sclerosis, early research suggests. A small-scale study by researchers at the Sapienza University of Rome has raised hopes that the disease can be warded off when early symptoms appear. More research is needed before the BCG vaccine can be trialled on MS patients. The MS Society said the chance to take a safe and effective preventative treatment after a first MS-like attack would be a huge step forward. MS is a disease affecting nerves in the brain and spinal cord, causing problems with muscle movement, balance and vision. Early signs include numbness, vision difficulties or problems with balance. About half of people with a first episode of symptoms go on to develop MS within two years, while 10% have no more problems. In the study, published in the journal Neurology, Italian researchers gave 33 people who had early signs of MS an injection of BCG vaccine. The other 40 individuals in the study were given a placebo. After five years, 30% of those who received the placebo had not developed MS, compared with 58% of those vaccinated. "These results are promising, but much more research needs to be done to learn more about the safety and long-term effects of this live vaccine," said study leader Dr Giovanni Ristori. "Doctors should not start using this vaccine to treat MS or clinically isolated syndrome." BBC © 2013
Keyword: Multiple Sclerosis
Link ID: 19003 - Posted: 12.05.2013
Philip Ball Some animals, like some people, are more aggressive than others: it is just the way they are. But research suggests that for birds at least, it is not always easy to tell which is which. Some birds are inclined to give out exaggerated signs of their aggressiveness, others to underplay it. It is rather like the menacing biker who turns out to be a pussycat, or the geek who will break a bottle over your head. But the analogy with humans goes only so far, because many birds announce their aggression about mating and territory not by appearance but through song and gesture. For example, behavioural ecologist Michael Beecher and his colleagues at the University of Washington in Seattle have observed how the song sparrow (Melospiza melodia) indicates its intention to attack a dummy bird (see video above) or a loudspeaker playing bird songs by either vocalizing distinctive ‘soft songs’ or waving its wings (see video below), both of which are perceived as threatening1. Violent tendencies Both aggressive signalling and the ensuing violent behaviour vary from one bird to another, in a way that correlates with other personality traits such as boldness2. But these attributes also vary for a single individual at different times: birds can have particularly grouchy or placid days. Nonetheless, the degree of aggression implied by the precursory signals generally reflects the actual behaviour, in what evolutionary biologists call an honest signal. But it's not always honest. Earlier this year, Beecher's team showed1 that there is some variability in aggressive signalling that does not match behaviour: a bird might act stroppy but not follow through with an attack. © 2013 Nature Publishing Group
By CARL ZIMMER Scientists have found the oldest DNA evidence yet of humans’ biological history. But instead of neatly clarifying human evolution, the finding is adding new mysteries. In a paper in the journal Nature, scientists reported Wednesday that they had retrieved ancient human DNA from a fossil dating back about 400,000 years, shattering the previous record of 100,000 years. The fossil, a thigh bone found in Spain, had previously seemed to many experts to belong to a forerunner of Neanderthals. But its DNA tells a very different story. It most closely resembles DNA from an enigmatic lineage of humans known as Denisovans. Until now, Denisovans were known only from DNA retrieved from 80,000-year-old remains in Siberia, 4,000 miles east of where the new DNA was found. The mismatch between the anatomical and genetic evidence surprised the scientists, who are now rethinking human evolution over the past few hundred thousand years. It is possible, for example, that there are many extinct human populations that scientists have yet to discover. They might have interbred, swapping DNA. Scientists hope that further studies of extremely ancient human DNA will clarify the mystery. “Right now, we’ve basically generated a big question mark,” said Matthias Meyer, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and a co-author of the new study. Hints at new hidden complexities in the human story came from a 400,000-year-old femur found in a cave in Spain called Sima de los Huesos (“the pit of bones” in Spanish). The scientific team used new methods to extract the ancient DNA from the fossil. “This would not have been possible even a year ago,” said Juan Luis Arsuaga, a paleoanthropologist at Universidad Complutense de Madrid and a co-author of the paper. © 2013 The New York Times Company
By Neuroskeptic This morning, the world woke up to the news that Scientists discover the difference between male and female brains Britain’s Independent today actually made that their front page. They went on to discuss “the hardwired difference that could explain why men are ‘better at map reading’”. The rest of the world’s media were no less excited. Well. I don’t have time to get into criticizing the media or decrying gender stereotypes, so let’s just stick to the science. The study in question, published in PNAS, is called Sex differences in the structural connectome of the human brain. The authors used diffusion tensor imaging (DTI) to estimate the integrity of the white matter tracts going in various directions at each point in the brain. In a large sample of 428 males and 521 females aged from 8 to 22, they report sex differences in the pattern of white matter connectivity. In general, the female brains were ‘more connected’ than the male, except in the cerebellum: here’s the plot for a summary measure, the Participation Coefficient. I have two issues with this: Head Motion. A perennial Neuroskeptic favorite, this one. A paper just last week showed convincingly that even modest amounts of head movement during the MRI scan causes changes in DTI. Various commentators on Twitter and elsewhere swiftly pointed out that it’s not implausible that men and women might move different amounts on average, so that might account for at least some of these results.
People with dementia who exercise improve their thinking abilities and everyday life, a body of medical research concludes. The Cochrane Collaboration carried out a systematic review of eight exercise trials involving more than 300 patients living at home or in care. Exercise did little for patients' moods, the research concluded. But it did help them carry out daily activities such as rising from a chair, and boosted their cognitive skills. Whether these benefits improve quality of life is still unclear, but the study authors say the findings are reason for optimism. Dementia affects some 800,000 people in the UK. And the number of people with the condition is steadily increasing because people are living longer. It is estimated that by 2021, the number of people with dementia in the UK will have increased to around one million. With no cure, ways to improve the lives of those living with the condition are vital. Researcher Dorothy Forbes, of the University of Alberta, and colleagues who carried out the Cochrane review, said: "Clearly, further research is needed to be able to develop best practice guidelines to enable healthcare providers to advise people with dementia living at home or in institutions. "We also need to understand what level and intensity of exercise is beneficial for someone with dementia." BBC © 2013
Link ID: 18999 - Posted: 12.05.2013
By James Gallagher Health and science reporter, BBC News The number of people living with dementia worldwide is set to treble by 2050, according to a new analysis. Alzheimer's Disease International says 44 million people live with the disease, but that figure will increase to 135 million by 2050. The figures were released ahead of the G8 dementia summit in London next week. In the UK, dementia research receives one eighth of the amount of funding that is spent on cancer, which charities say is insufficient. Alzheimer's Disease International expects increasing life expectancies to drive a surge in cases in poor and middle-income countries, particularly in South East Asia and Africa. Currently 38% of cases are in rich countries. But that balance is predicted shift significantly by 2050, with 71% of patients being in poor and middle-income countries. The report says most governments are "woefully unprepared for the dementia epidemic". Marc Wortmann, the executive director at Alzheimer Disease International, said: "It's a global epidemic and it is only getting worse - if we look into the future the numbers of elderly people will rise dramatically." Jeremy Hughes, chief executive of the UK's Alzheimer's Society, said: "Dementia is fast becoming the biggest health and social care challenge of this generation. "We must tackle dementia now, for those currently living with the condition across the world and for those millions who will develop dementia in the future. BBC © 2013
Link ID: 18998 - Posted: 12.05.2013
Ian Sample, science correspondent Scientists have drawn on nearly 1,000 brain scans to confirm what many had surely concluded long ago: that stark differences exist in the wiring of male and female brains. Maps of neural circuitry showed that on average women's brains were highly connected across the left and right hemispheres, in contrast to men's brains, where the connections were typically stronger between the front and back regions. Ragini Verma, a researcher at the University of Pennsylvania, said the greatest surprise was how much the findings supported old stereotypes, with men's brains apparently wired more for perception and co-ordinated actions, and women's for social skills and memory, making them better equipped for multitasking. "If you look at functional studies, the left of the brain is more for logical thinking, the right of the brain is for more intuitive thinking. So if there's a task that involves doing both of those things, it would seem that women are hardwired to do those better," Verma said. "Women are better at intuitive thinking. Women are better at remembering things. When you talk, women are more emotionally involved – they will listen more." She added: "I was surprised that it matched a lot of the stereotypes that we think we have in our heads. If I wanted to go to a chef or a hairstylist, they are mainly men." The findings come from one of the largest studies to look at how brains are wired in healthy males and females. The maps give scientists a more complete picture of what counts as normal for each sex at various ages. Armed with the maps, they hope to learn more about whether abnormalities in brain connectivity affect brain disorders such as schizophrenia and depression. © 2013 Guardian News and Media Limited
By PAM BELLUCK Scientists have been eager to see if oxytocin, which plays a role in emotional bonding, trust and many biological processes, can improve social behavior in people with autism. Some parents of children with autism have asked doctors to prescribe it, although it is not an approved treatment for autism, or have purchased lower-dose versions of the drug over the counter. Scientifically, the jury is out, and experts say parents should wait until more is known. Some studies suggest that oxytocin, sometimes called the “love hormone,” improves the ability to empathize and connect socially, and may decrease repetitive behaviors. Others find little or no impact, and some research suggests that it can promote clannish and competitive feelings, or exacerbate symptoms in people already oversensitive to social cues. Importantly, nobody knows if oxytocin is safe or desirable to use regularly or long term. Now, the first study of how oxytocin affects the brains of children with autism finds hints of promise — and also suggestions of what its limitations might be. On the promising side, the small study, published Monday in The Proceedings of the National Academy of Sciences, found that the hormone, given as an inhalant, generated increased activity in parts of the brain involved in social connection. This suggests not only that oxytocin can stimulate social brain areas, but also that in children with autism these brain regions are not irrevocably damaged but are plastic enough to be influenced. The limitations could include a finding that oxytocin prompted greater brain activity in children with the least severe autism. Some experts said that this could imply that oxytocin may work primarily in less-impaired people, but others said it might simply suggest that different doses are needed. © 2013 The New York Times Company