Chapter 5. Hormones and the Brain

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By Jessica Wright, Clinicians can reliably diagnose autism in some toddlers roughly two years earlier than the typical age of diagnosis, a new study suggests. The researchers assessed more than 1,200 toddlers for autism at least twice using standard diagnostic tools. They diagnosed roughly one in three with the condition by age 2; 84 percent of these toddlers retained the label at their last visit, which was at age 3 on average. The finding suggests clinicians should take autism traits in toddlers seriously, says co-lead researcher Karen Pierce, professor of neurosciences at the University of California, San Diego. “If children meet criteria and they do show signs and symptoms, don’t wait; let’s get them the help and the treatment that they need,” Pierce says. Experts are divided on whether autism can reliably be diagnosed before age 3. The American Academy of Pediatrics recommends screening for autism starting at 18 months. However, the U.S. Preventive Services Task Force—a government panel that makes recommendations about preventive medicine—has said there is insufficient evidence to recommend universal screening before 3. The new study suggests that early screening and diagnosis may benefit some proportion of children: It indicates that some toddlers are likely to have clear enough signs of autism to warrant a diagnosis before 2 years of age, says Zachary Warren, associate professor of pediatrics, psychiatry and behavioral sciences at Vanderbilt University in Nashville, Tennessee. “The study shows that well-trained, expert teams evaluating young kids with autism are able to pick up concerns at fairly young ages for some kids,” says Warren, who was not involved in the work. “It’s an interesting and creative approach to understanding screening and diagnosis.” © 2019 Scientific American

Keyword: Autism
Link ID: 26243 - Posted: 05.17.2019

By Nicholette Zeliadt, Two drugs that alter the activity of the hormone vasopressin seem to improve social communication in people with autism. The findings come from two independent clinical trials published today in Science Translational Medicine. The results are encouraging, but some experts urge caution, saying the methods used to assess the drugs were not designed for that purpose. Vasopressin is related to oxytocin, a hormone thought to govern social bonding. But vasopressin’s link to autism is far from simple: There’s evidence implicating both too little and too much of the hormone in people with the condition. Advertisement The two drugs also target vasopressin in opposite ways. One of them, balovaptan, blocks a receptor for vasopressin in the brain and dampens the hormone’s activity. The other is a nasal spray containing vasopressin. Despite their opposing modes of action, both drugs appear to boost social function in autistic people; neither has serious side effects. The findings are noteworthy because no drugs are available to treat autism’s core traits, says Eric Hollander, professor of psychiatry and behavioral sciences at Albert Einstein College of Medicine in New York, who was not involved in either study. “These two studies provide important information that the vasopressin or vasopressin and oxytocin systems are important in social communication,” he says. “Different agents affecting these systems may ultimately be helpful in terms of new treatments for autism.” © 2019 Scientific American

Keyword: Autism; Hormones & Behavior
Link ID: 26202 - Posted: 05.03.2019

By Kelly Servick Many people with autism have trouble making eye contact, reading the emotions in other faces, and sharing affection. And no drugs are approved to treat such social impairments. Now, results from a small academic clinical trial suggest boosting levels of vasopressin—a hormone active in the brain that’s known to promote bonding in many animals—can improve social deficits in children with autism. But in a confusing twist, a larger, company-sponsored trial that took the reverse approach, tamping down vasopressin’s effects, also found some improvements in adults with autism. “I’ve never seen this before,” Kevin Pelphrey, a neuroscientist who studies autism at the University of Virginia in Charlottesville, says of the conflicting results. He and others say the vasopressin-blocking approach doesn’t have much support from previous animal research. The new study showed some benefits but failed to meet the main endpoint set out by investigators. Still, he says, both studies suggest vasopressin’s signaling in the brain plays a key role in autism and “give me a lot of renewed excitement” for treating the condition. Though vasopressin seems to stimulate social bonding in animals, the hormone’s activity in the brain isn’t fully understood, and its effects vary by species and context. Blocking its activity in the brains of some rodents prevents them from forming an attraction to a mate. But in a species of asocial hamster, injecting it into a male’s brain seems to stimulate aggression. © 2019 American Association for the Advancement of Science.

Keyword: Autism; Hormones & Behavior
Link ID: 26197 - Posted: 05.02.2019

By Gina Kolata The Court of Arbitration for Sport in Zurich has ruled that women with very high testosterone levels — far above the normal range — cannot compete against other women in races from 400 meters to one mile unless they take drugs to suppress production of the hormone. The ruling prevents Caster Semenya, 28, an elite runner and Olympic champion from South Africa, from competing in those races because her testosterone levels are naturally very high. She had challenged attempts to disqualify her from racing as a woman. The science underpinning that decision is complicated, raising difficult questions about biology, fairness and gender identity. What is testosterone? Where does it come from in women? It’s a hormone, an androgen, that has a variety of effects on the body. Women and men produce testosterone, but women don’t make nearly as much In men, high levels of testosterone are made by the testes. Much lower levels are produced in the adrenal glands, which rest above the kidneys. Women also make testosterone in their adrenal glands, and in their ovaries. But testes produce much more: Testosterone levels in men are 295 to 1,150 nanograms per deciliter of blood, while the levels in the women are 12 to 61 nanograms per deciliter of blood. Testosterone “builds muscle,” said Dr. Benjamin D. Levine, who studies sex differences in athletic performance at the University of Texas Southwestern Medical Center. “It builds skeletal muscle, it builds cardiac muscle. It increases the number of red blood cells.” The effects are seen whether the hormone is naturally present or introduced with drugs. In one of the most infamous examples, women who represented East Germany at the Olympic Games in the ’70s and ’80s achieved astounding success after they were unknowingly doped with anabolic steroids including testosterone. “The science is quite clear,” said Dr. Aaron Baggish of Massachusetts General Hospital, who is an expert on testosterone’s effects. “An androgenized body has a performance advantage.” © 2019 The New York Times Company

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 26196 - Posted: 05.02.2019

By Simon Baron-Cohen At the annual meeting of the International Society for Autism Research (INSAR) in Montreal, Canada, this week, one topic likely to be widely debated is the concept of neurodiversity. It is dividing the autism community, but it doesn’t have to. The term “neurodiversity” gained popular currency in recent years but was first used by Judy Singer, an Australian social scientist, herself autistic, and first appeared in print in the Atlantic in 1998. Neurodiversity is related to the more familiar concept of biodiversity, and both are respectful ways of thinking about our planet and our communities. The notion of neurodiversity is very compatible with the civil rights plea for minorities to be accorded dignity and acceptance, and not to be pathologized. And whilst the neurodiversity movement acknowledges that parents or autistic people may choose to try different interventions for specific symptoms that may be causing suffering, it challenges the default assumption that autism itself is a disease or disorder that needs to be eradicated, prevented, treated or cured. Many autistic people—especially those who have intact language and no learning difficulties such that they can self-advocate—have adopted the neurodiversity framework, coining the term “neurotypical” to describe the majority brain and seeing autism as an example of diversity in the set of all possible diverse brains, none of which is “normal” and all of which are simply different. © 2019 Scientific American

Keyword: Autism
Link ID: 26185 - Posted: 04.30.2019

Jessica Wright Sequencing can identify mutations linked to autism even before a child’s birth—especially in cases where doctors suspect problems, two new studies suggest. In the studies, scientists sequenced fetal DNA only when ultrasounds revealed atypical development of limbs or other organs, and they gave families only the results that seemed to explain those problems But there is a real risk that others might use the technique to test for mutations in any fetus—and to relay all the results to parents—without proper oversight, says Ronald Wapner, professor of obstetrics and gynecology at the Columbia Institute for Genomic Medicine, who led one of the studies. “Not everybody should be doing this; it should be in the hands of people that have expertise,” he says. Other types of analyses already detect mutations in a fetus: Some detect large DNA segments that are swapped between chromosomes, and others can pick up on missing or duplicated copies of DNA fragments. The new studies are among the first to scan for mutations across the fetal exome—essentially, the collection of genes in a genome. The field is fraught with ethical questions, including whether parents might choose to terminate a pregnancy based on the results. But the researchers note that most of the mutations they found pose serious health risks, which could be treated at birth or in utero. © 1986 - 2019 The Scientist

Keyword: Autism; Genes & Behavior
Link ID: 26168 - Posted: 04.24.2019

Nicola Davis Philandering men have unfaithfulness written all over their faces, according to research that suggests men and women are able to spot cheating chaps just by looking at them. Experts found men with more “masculine” faces were more likely to be thought to be unfaithful, and such men also self-reported more cheating or “poaching” of other men’s partners. However, they stressed the results were modest, and said people should be wary of deciding whether someone is a love rat based on impressions of facial features alone. The team said being suspicious of men with masculine features – such as a strong browridge, strong jaw and thinner lips – might have offered an evolutionary advantage, allowing heterosexual women to spot a flaky partner and men to recognise a potential rival who might seduce their partner or leave them raising someone else’s child. Previous research has suggested women are able to spot unfaithful men from their mugshot, with the masculinity of the man’s face a key factor in the judgment, while weaker effects have been found for men weighing up images of women. However, it was unclear whether people could also spot a philanderer of the same sex. Writing in the journal Royal Society Open Science, researchers described how they asked heterosexual white participants to judge the facial features of 189 white adults who had been photographed and taken part in previous research. Overall, 293 men and 472 women rated pictures of women, while 299 men and 452 women judged images of men, rating on a scale of one to 10 how likely they thought each person was to be unfaithful. © 2019 Guardian News & Media Limited

Keyword: Sexual Behavior; Evolution
Link ID: 26147 - Posted: 04.17.2019

By Denise Gellene Paul Greengard, an American neuroscientist whose 15-year quest to understand how brain cells communicate provided new insights into psychological diseases and earned him a Nobel Prize, and who used his entire $400,000 award to create an academic prize in memory of the mother he never knew, died on Saturday in Manhattan. He was 93. His death was confirmed by Rockefeller University, where he had worked since 1983. Dr. Greengard received the 2000 Nobel Prize in Physiology or Medicine with Dr. Arvid Carlsson of Sweden and Dr. Eric R. Kandel of the United States for independent discoveries related to the ways brain cells relay messages about movement, memory and mental states. Their discoveries offered new insights into disorders linked to errors in cell communication, such as Parkinson’s disease, schizophrenia, bipolar disorder and drug addiction. Dr. Greengard’s research described how cells react to dopamine, an important chemical messenger in the brain. His work provided the underlying science for many antipsychotic drugs, which modulate the strength of chemical signals in the brain. “Our work shows the details of how dopamine produces these effects — in other words, what’s wrong in these diseases and what can be done to correct them,” Dr. Greengard said. Dr. Greengard’s research extended from the late 1960s to the mid-1980s. For much of the period, his work was ignored. A majority of biologists believed brain cells communicated through the use of electrical signals. To them, the only thing that mattered was whether a cell fired off a signal. © 2019 The New York Times Company

Keyword: Drug Abuse; Schizophrenia
Link ID: 26139 - Posted: 04.15.2019

Wency Leung A new Canadian study on how the birth control pill affects a woman’s ability to think is the latest to address a decades-old knowledge gap researchers say needs to be fixed: How oral contraceptives impact the brain. The study aims to test the working memory of around 60 young women who use oral contraceptives, says researcher Laura Gravelsins, a PhD student with the Einstein Lab on cognitive neuroscience, gender and health at the University of Toronto. Gravelsins is among a number of researchers exploring an area that has historically been overlooked. Since the introduction of the pill in the 1960s, hormonal contraceptives – which contain estrogen, progestin, or a combination of both – have become a preferred option for many women. Yet, due, in part, to past assumptions that the brain operates separately from the rest of body and a general lack of research into women’s health, scientists are only now investigating how they may influence mood and cognition. Another area that needs exploration is how sex hormones, including those naturally produced by the body, influence developing brains. At the University of British Columbia, researchers are currently recruiting 300 girls, ages 13 to 15, to study what role sex hormones may play in their emotional development. “We need more research,” says Dr. Gillian Einstein, a professor of psychology at University of Toronto and the Wilfred and Joyce Posluns Chair in Women’s Brain Health and Aging. “Women should demand more research on this.”

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 26110 - Posted: 04.03.2019

By Tiffany Hsu Amazon has removed the online listings for two books that claim to contain cures for autism, a move that follows recent efforts by several social media sites to limit the availability of anti-vaccination and other pseudoscientific material. The books, “Healing the Symptoms Known as Autism” and “Fight Autism and Win,” which had previously been listed for sale in Amazon’s marketplace, were not available on Wednesday. The company confirmed that the listings had been removed, but declined to discuss why or whether similar books would be taken down in the future. Several such books were still listed on Wednesday. In an article published this week, Wired magazine noted that Amazon is crowded with titles promoting unproven treatments for autism that include “sex, yoga, camel milk, electroconvulsive therapy and veganism.” There is no cure for autism spectrum disorder, but there are medications that can help address associated symptoms like high energy levels and depression, according to the Centers for Disease Control and Prevention. The agency has found that as many as a third of parents with an autistic child have tried treatments that most pediatricians do not recommend, and that up to 10 percent may be using potentially dangerous tactics. The books that were listed on Amazon were both written more than five years ago and have together generated more than 600 customer reviews. “Healing the Symptoms Known as Autism” recommends that autistic children drink and bathe in chlorine dioxide, a compound often referred to as “Miracle Mineral Solution.” In 2010, the Food and Drug Administration described it as “a potent bleach used for stripping textiles and industrial water treatment” that “can cause nausea, vomiting, diarrhea, and symptoms of severe dehydration.” Representative Adam Schiff, Democrat of California, wrote an open letter this month to Jeff Bezos, Amazon’s chief executive, chiding the company about the failure of its algorithms to “distinguish quality information from misinformation or misleading information.” © 2019 The New York Times Company

Keyword: Autism; Neuroimmunology
Link ID: 26033 - Posted: 03.14.2019

Laura Sanders Young nerve cells derived from people with autism are precocious, growing bigger and developing sooner than cells taken from people without autism, a new study shows. The results, described January 7 in Nature Neuroscience, hint that in some cases nerve cells veer off course early in brain development to ultimately cause the disorder. As a proxy of brain growth, researchers led by Simon Schafer of the Salk Institute in La Jolla, Calif., transformed skin cells from people with and without autism into stem cells that then developed into nerve cells in the lab. Along the way, the scientists monitored the cells’ growth and the behavior of their genes. Compared with cells derived from five people without autism, cells from eight people with autism grew bigger, with longer and more elaborate branches, the researchers found. Three-dimensional balls called organoids made of the autism-derived cells were bulkier, too. In addition to this physical development, a group of genes important for brain development switched on sooner. Trouble in the autism-derived cells, however, actually began a bit earlier, just as the cells were on the cusp of becoming nerve cells. At the neural stem cell stage, certain spots of these cells’ chromatin — tightly packed genetic material — were more open and accessible than they should have been, an unfolding that can lead to abnormally active genes. The results show that open chromatin “can have major effects on neuronal development,” says neuroscientist David Amaral of the University of California, Davis. |© Society for Science & the Public 2000 - 2018.

Keyword: Autism
Link ID: 25856 - Posted: 01.11.2019

By Jane E. Brody Dr. Gayatri Devi’s patient, a 55-year-old former headmistress, had good reason to be distraught. The woman had a yearlong history of progressive memory loss and behavioral problems and was referred to Dr. Devi, a neurologist, with a possible diagnosis of frontotemporal dementia. As Dr. Devi recounted in the journal Obstetrics & Gynecology, the woman’s once prodigious memory had seriously deteriorated and she’d become increasingly irritable. She had difficulty organizing tasks, keeping track of belongings, setting goals, making plans and seeing them through. Yet the results of medical and neurological tests and brain scans were normal. Noting that the woman had gone through menopause a year earlier, Dr. Devi traced her symptoms to the decline in estrogen stimulation of the brain that occurs in all women at menopause with varying effects. Some are more sensitive to falling estrogen levels than others. With a likely diagnosis of menopause-related cognitive impairment, the doctor prescribed hormone-replacement therapy. Within 15 months, the woman’s behavioral symptoms had disappeared and her learning ability and memory were back to normal. She was able to complete a demanding graduate program and assume a new leadership position in education. This woman’s case was admittedly extreme, but Dr. Devi told me that “60 percent of women go through menopause-related cognitive impairment” that, when serious enough to be brought to medical attention, is too often misdiagnosed as “mild cognitive impairment,” a precursor to dementia. © 2018 The New York Times Company

Keyword: Hormones & Behavior; Development of the Brain
Link ID: 25793 - Posted: 12.17.2018

By Lina Zeldovich, It was 1924 when the 12-year-old boy was brought to the Moscow clinic for an evaluation. By all accounts, he was different from his peers. Other people did not interest him much, and he preferred the company of adults to that of children his own age. He never played with toys: He had taught himself to read by age 5 and spent his days reading everything he could instead. Thin and slouching, the boy moved slowly and awkwardly. He also suffered from anxiety and frequent stomachaches. At the clinic, a gifted young doctor, Grunya Efimovna Sukhareva, saw the boy. Caring and attentive, she observed him with a keen eye, noting that he was “highly intelligent” and liked to engage in philosophical discussions. By way of a diagnosis, she described him as “an introverted type, with an autistic proclivity into himself.” ‘Autistic’ was a relatively new adjective in psychiatry at the time. About a decade earlier, Swiss psychiatrist Eugen Bleuler had coined the term to describe the social withdrawal and detachment from reality often seen in children with schizophrenia. Sukhareva’s characterization came nearly two decades before Austrian doctors Leo Kanner and Hans Asperger published what have long been considered to be the first clinical accounts of autism. At first, Sukhareva used ‘autistic’ in the same way Bleuler did—but as she started to see other children with this trait, she decided to try to characterize it more fully. Over the course of the following year, she identified five more boys with what she described as “autistic tendencies.” All five also showed a preference for their own inner world, yet each had his own peculiarities or talents. One was an extraordinarily gifted violinist but struggled socially; another had an exceptional memory for numbers but could not recognize faces; yet another had imaginary friends who lived in the fireplace. None were popular with other children, she noted, and some saw peer interaction as useless: “They are too loud,” one boy said. “They hinder my thinking.” © 2018 Scientific American

Keyword: Autism
Link ID: 25668 - Posted: 11.12.2018

Ian Sample In daylight hours there is so little melatonin in the bloodstream that it is barely detectable. But when the sun goes down, the eyes sense the failing light, and part of the hippocampus signals the pineal gland, a pea-sized lump of tissue near the centre of the brain, to ramp up production of the sleep-promoting hormone. Levels of melatonin rise sharply from 9pm, inducing feelings of sleepiness, and remain high until the following morning. Much of the research on prescribing melatonin for children with sleep problems has focused on those with disorders such as autism, ADHD and intellectual disability (ID). For good reason too: sleeping difficulties are far more common and pronounced in children with neurodevelopmental or psychiatric disorders. For them, small doses of melatonin can be safe and effective. In one recent study, researchers from Southampton University monitored the sleep patterns of 45 children with autism, ADHD, or ID, and found that a third fell asleep faster, slept longer, and woke less frequently at night on low dose (2.5-3mg) melatonin. Above 6mg per night there was little extra benefit. A poor night’s sleep can be caused by any number of factors, but there is good evidence that screen time matters, whether it is TV, computer, tablet or mobile phone. A recent review of scientific papers on the issue found that 90% linked screen time to poor sleep in schoolchildren and adolescents. Part of the problem is obvious: being online at bedtime eats into the hours left for sleep, and it hardly helps people to wind down for the night. But glowing screens can affect sleep directly by suppressing the natural production of melatonin. Using an iPad on full brightness for two hours, for example, has been shown to suppress melatonin levels. © 2018 Guardian News and Media Limited

Keyword: Biological Rhythms; Hormones & Behavior
Link ID: 25640 - Posted: 11.03.2018

by Lena Simon Four limbs. Warm blood. A love for cheese. And a hatred for infidelity. Although this may sound characteristic of the average Wisconsinite, the previous is actually also true for the California mouse. A recent University of Wisconsin news release revealed research that shows California pair-bonded mice become increasingly vocal after infidelity experiences. Experiments were designed to test how communication changes after mice have been given the opportunity to be “unfaithful” to their bonded mate. The California deer mouse, or Peromyscus californicus, is part of only 3 to 5 percent of mammal species that practice any kind of monogamy, per research from the National Science Foundation. At UW, research on the California mouse is ongoing. Josh Pultorak, a biology instructor at Madison Area Technical College and UW’s Wisconsin Institute for Discovery, led this research. He and his collaborators identified several types of sounds that the California mouse makes, all of which are ultrasonic — unable to be heard by the human ear unless slowed down to about 5 percent of their original speed. These include chirps — or “sweeps,” which are usually more peaceful sounds — and barks, which indicate aggression. Microbes in your gut could hold cure to diabetesThere are millions of microbes living in your gut. They help you digest and access nutrients your own organs would Read… The Badger Herald, 1995 - 2018

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 25637 - Posted: 11.02.2018

By Alycia Halladay Click-worthy health and science headlines are an essential currency in today’s media world. When they pertain to autism, they might include phrases like “groundbreaking trial,” “offer hope” or “game-changer.” But for people with autism and their families, these headlines and the research news stories they highlight often bring false hope, confusion—or worse. There is something about autism, a disorder that remains widely misunderstood, that seems to encourage the promulgation of news coverage about potential “breakthroughs” and unorthodox treatment approaches. A nearly constant stream of headlines touts promising new findings that supposedly help explain the origins of autism spectrum disorder (ASD), improve our understanding of its key features or reveal novel ways to treat the symptoms. This attention is a mixed blessing. It can encourage talented scientists to design research to better understand autism. It also generates support for advocacy efforts and research funding, and I have seen it motivate people to participate in research studies. However, there is a dark side to this almost insatiable interest in autism science news: it has created an environment that encourages media hype of early, preliminary findings, with headlines that are tantalizing but not always accurate. The hype machine also too often promotes mediocre or even bad science, which ultimately puts people with autism at risk. © 2018 Scientific American

Keyword: Autism
Link ID: 25635 - Posted: 11.02.2018

By George Musser, The forest is still—until, out of the corner of my eye, I notice a butterfly flutter into view. At first it is barely perceptible, but as I watch the butterfly more intently, the trees around it darken and the insect grows brighter. The more I marvel at it, the more marvelous it becomes, making it impossible for me to look away. Before long the entire forest recedes, and the butterfly explodes into a red starburst, like a fireworks display. Everything goes dark. Then, dozens of white dots swarm around me. On my left, they are just dots. On my right, they leave long trails of spaghetti-like light. The contrast makes me acutely conscious that the present is never experienced as a mathematical instant; it has some duration, and the perception of that can vary with context. The sensation evaporates as soon as I take off my headset. This immersive virtual-reality (VR) experience was a preliminary look at Beholder, an art installation at the Victoria and Albert Museum in London in September that sought to recreate how autistic people perceive the world. It is now on display at the gallery that commissioned it, Birmingham Open Media. The project’s creator, Matt Clark, has a severely autistic 15-year-old son, Oliver. “He can’t talk; his behaviors are extremely challenging,” says Clark, creative director of United Visual Artists, an art and design group based in London. Clark built Beholder so he and others could see the world through his son’s eyes. He collaborated with artists who either are on the spectrum or have family members who are. © 2018 American Association for the Advancement of Science

Keyword: Autism; Vision
Link ID: 25621 - Posted: 10.27.2018

By Elizabeth Pennisi One of biology’s enduring mysteries is how some animals—from humans to honey bees—became so social. Now, a study suggests that, in the inconspicuous sweat bee, changes to the expression of a single gene could determine which bees are solitary and which are social. The gene, which has previously been linked to autism in humans, has also been connected to social behavior in animals like mice and locusts. The new discovery puts scientists one step closer toward demonstrating a common evolutionary basis for social behavior. “People have been taking about the genetics of sociality for years,” says Bernard Crespi, an evolutionary biologist at Simon Fraser University in Vancouver, Canada, who was not involved with the work. “Finding this gene is a real watershed for the field.” Sweat bees don’t have the same massive colonies as honey bees, whose hundreds of workers care for and protect a single egg-laying queen. But the tiny, gentle bees have some interesting social arrangements: In some groups and species, workers help a reproducing queen, as honey bees do; in other groups, sweat bee females tend their own broods. This difference has led scientists to think sweat bees may hold the key to understanding how more complex insect societies began to evolve. © 2018 American Association for the Advancement of Science

Keyword: Autism; Genes & Behavior
Link ID: 25592 - Posted: 10.18.2018

Laura Sanders WASHINGTON — As the number of children diagnosed with autism spectrum disorder increases, so too has research on the complex and poorly understood disorder. With powerful genetic tools, advanced brain-imaging methods and large groups of children to study, the field is poised to make big contributions in understanding — and potentially treating — autism. Neuroscientist Kevin Pelphrey, who is formerly of George Washington University in Washington, D.C., but has recently moved to the University of Virginia in Charlottesville, studies autism’s beginnings. He described some of his findings about the link between brain development and the disorder on October 15 at a meeting of the Council for the Advancement of Science Writing. Here are some of the key points Pelphrey made on how autism may get its start in the developing brain, how the disorder is different between boys and girls, and how large, long-term studies of children with autism might yield clues about the condition. What causes autism spectrum disorder? For most cases, no one knows. There’s likely no single cause — environmental and genetic risk factors work in combination. In some children, rare mutations in key genes have been linked to the disorder. More commonly, many genetic changes, each with a small influence on overall risk, may increase a child’s likelihood of developing the disorder. With the number of autism diagnoses growing, partly due to better detection, researchers are looking at potential factors beyond genetics, such as parents’ age, premature birth and maternal obesity. When does the disorder begin? |© Society for Science & the Public 2000 - 20

Keyword: Autism
Link ID: 25584 - Posted: 10.17.2018

Ashley P. Taylor Researchers have long believed that autism spectrum disorder is caused by some sort of imbalance between excitation and inhibition in the brain. In particular, studies have suggested that something is unusual about signaling controlled by the inhibitory neurotransmitter, γ-aminobutyric acid (GABA), whether it be lower levels of GABA or the receptor it binds to. But a study published last week (October 3) in Science Translational Medicine, which zeroed in on GABA receptor levels, finds no evidence that their abundance is any different between people with autism and people without. “We were unable to identify that individuals with autism had differences in GABAA receptor binding,” says Declan Murphy, a psychiatrist who studies brain development and neuropsychiatric disorders at King’s College London, who co-led the work with the Karolinska Institute’s Jacqueline Borg. “That’s important because it had previously been reported that they do have abnormalities in GABAA receptor binding, number one, and number two, it’s important because GABAA is a target of a number of pharmaceutical companies in terms of developing new treatments,” Murphy adds. GABAA is the most common form of the neurotransmitter in human brains, and since the early 2000s, reports have been piling up that associate deficits in the production of GABA or in GABA receptors to autism. For instance, studies in postmortem brains of people who had autism spectrum disorder (ASD) and of neurotypical subjects, led by Gene Blatt, a neuroscientist at the Hussman Institute for Autism in Baltimore, had found that people who had ASD had lower levels of the enzyme that makes GABA. Blatt’s investigations also found that people with ASD had lower GABAA receptor levels in the cingulate cortex and hippocampus. And an in vivo study by another group had detected reduced GABAA levels in the brains of children with ASD. © 1986 - 2018 The Scientist.

Keyword: Autism
Link ID: 25579 - Posted: 10.16.2018