Chapter 5. Hormones and the Brain
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By Daisy Yuhas, Spectrum on March 22, 2017 In children with a deletion on chromosome 22, having autism does not boost the risk of developing schizophrenia later in life, according to a new study1. The children in the study have 22q11.2 deletion syndrome, which is linked to a 25-fold increase in the risk of developing a psychotic condition such as schizophrenia. A deletion in the region is also associated with an increased risk of autism. Some researchers have suggested that the relatively high autism prevalence in this population is the result of misdiagnoses of early signs of schizophrenia. The new findings, published 21 January in Schizophrenia Research, support an alternate theory: Autism and schizophrenia are independent outcomes of the same genetic syndrome. If there is a relationship between the two conditions, “that can only be a very small, probably negligible effect,” says lead investigator Jacob Vorstman, assistant professor of child psychiatry and genetics at the University Medical Center Utrecht in the Netherlands. The new findings could help guide clinical care, says Opal Ousley, assistant professor of psychiatry at the Emory Autism Center in Atlanta. If prenatal testing picks up the 22q11.2 deletion, for instance, clinicians could discuss the risk of both autism and schizophrenia with parents. © 2017 Scientific American
By Jill Serjeant NEW YORK (Reuters) - Long-running children's television show "Sesame Street" is welcoming a new kid to the block - a Muppet with autism called Julia. A redhead who loves to sing and remembers the words to lots of songs, Julia will debut on the show for preschoolers on April 10 after a five-year outreach effort to families and experts on autism, Sesame Workshop said on Monday. "For years, families of children with autism have asked us to address the issue," Dr. Jeanette Betancourt, senior vice president of U.S. social impact at the nonprofit Sesame Workshop, said in a statement. One in 68 American children is currently diagnosed with autism, according to the Centers for Disease Control and Prevention, an increase of some 119 percent since 2000. Autism is a developmental disorder present from early childhood, characterized by difficulty in communicating and forming relationships with other people and in using language and abstract concepts Stacey Gordon, the puppeteer who will perform the role of Julia, and Christine Ferraro who wrote her part, both have family members who are on the autism spectrum. "It's important for kids without autism to see what autism can look like," Gordon told the CBS show "60 Minutes" in a preview on Sunday. "Had my son's friends been exposed to his behaviors through something that they had seen on TV before they experienced them in the classroom, they might not have been frightened. They might not have been worried when he cried. They would have known that he plays in a different way and that that's okay," she added. © 2017 Scientific American
Link ID: 23387 - Posted: 03.22.2017
By Abby Olena Researchers have shown that a hormone secreted by bone, called lipocalin 2 (LCN2), suppresses appetite in mice. The results, published today (March 8) in Nature, suggest that LCN2 crosses the rodents’ blood-brain barrier and binds a receptor in the hypothalamus. The team also found a link between body weight and LCN2 levels in people with type 2 diabetes. The authors “have identified a protein that’s secreted from bone that has a pretty significant impact on feeding behavior,” Lora Heisler of the University of Aberdeen in Scotland, who did not participate in the work, told The Scientist. “And the fact that they found that some supporting evidence in humans is really exciting.” “We have found a new role for bone as an endocrine organ, and that is its ability to regulate appetite,” said study coauthor Stavroula Kousteni of Columbia University in New York City. Scientists had previously identified LCN2 as a protein expressed in fat cells, but Kousteni and colleagues showed that it is enriched 10-fold in osteoblasts. When they generated mice without LCN2 in their osteoblasts, levels of the circulating hormone dropped 67 percent. These mice ate more than control animals and showed increases in fat mass and body weight. When the authors injected LCN2 into wild-type or obese mice, the rodents ate less food. The treated animals showed decreases in body weight, fat mass, and weight gain. LCN2 injections also led to increases in insulin levels and glucose tolerance, the scientists showed. © 1986-2017 The Scientist
By Bahar Gholipour, Spectrum An analysis of whole-genome sequences from more than 5,000 people has unearthed 18 new candidate genes for autism. The study, the largest yet of its kind, was published this week in Nature Neuroscience. The new work identified 61 genes associated with autism, 43 of which turned up in previous studies. An independent study published last month looked at several autism genes and made a strong case for three of the new genes2. Most of the new candidates play roles in cellular processes already implicated in autism and intellectual disability. They also point to possible new treatments. “Eighty percent of them involve common biological pathways that have potential targets for future medicines,” says study investigator Ryan Yuen, research associate at the Hospital for Sick Children in Toronto, Canada. The study is the largest analysis of whole genomes from people with autism and their family members to date. Participants are enrolled in MSSNG, an effort funded by Google and the nonprofit group Autism Speaks to analyze sequences from 10,000 people. Other studies typically focus on the coding regions of the genome, called theexomes. Most of the mutations identified in the new work land in genes, but some affect noncoding regions of the genome. Understanding the role of these noncoding mutations is a “challenging task,” says Ivan Iossifov, associate professor at Cold Spring Harbor Laboratory in New York, who was not involved in the study. “The more data that’s available, the better,” he says. “This paper provides a very useful resource for the community to further study.” © 2017 Scientific American,
Nicola Davis The mystery of why sheep get horny in the winter might have been solved, according to new research. Scientists say they have uncovered the key to the mechanism by which changes in the length of the day prompt certain animals to begin breeding, trigger the growth of horns and even change the thickness of their coat. The findings, the team add, could help farmers tinker with the timing of the lambing season. “Now we know what that link is we can start to understand how it can be controlled,” said David Bates, professor of oncology at the University of Nottingham and co-author of the research. It has long been known that changes in animals’ fertility over the seasons is linked to melatonin – a hormone released at night from the pineal gland in the brain. This hormone acts on another gland, the pituitary, affecting the levels of various sex hormones it produces. With the onset of fertility in sheep linked to longer periods of melatonin production, winter is the season for ovine Casanovas. But there is a puzzle. The region of the pituitary gland that detects melatonin is separate to the region that produces sex hormones. As a result, scientists had been baffled as to how melatonin ends up affecting the onset of fertility. “No-one has been able to find what the link is,” said Bates. Now Bates and colleagues from the University of Bristol say they have the answer. Writing in the journal PNAS, the team reveal the missing link is a protein, known as vascular endothelial growth factor, which is made in the region of the pituitary gland that detects melatonin. © 2017 Guardian News and Media Limited
By Jessica Wright, Spectrum The prevalence of autism in the United States has risen steadily since researchers first began tracking it in 2000. The rise in the rate has sparked fears of an autism ‘epidemic.’ But experts say the bulk of the increase stems from a growing awareness of autism and changes to the condition’s diagnostic criteria. Here’s how researchers track autism’s prevalence and explain its apparent rise. How do clinicians diagnose autism? There is no blood test, brain scan or any other objective test that can diagnose autism—although researchers are actively trying to develop such tests. Clinicians rely on observations of a person’s behavior to diagnose the condition. In the U.S., the criteria for diagnosing autism are laid out in the “Diagnostic and Statistical Manual of Mental Disorders” (DSM). The criteria are problems with social communication and interactions, and restricted interests or repetitive behaviors. Both of these ‘core’ features must be present in early development. What is the prevalence of autism in the U.S.? The Centers for Disease Control and Prevention (CDC) estimates that 1 in 68children in the U.S. have autism. The prevalence is 1 in 42 for boys and 1 in 189 for girls. These rates yield a gender ratio of about five boys for every girl. © 2017 Scientific American,
Link ID: 23305 - Posted: 03.03.2017
By Melissa Pandika Groundbreaking research suggests that a treatment for autism may come in the form of a probiotic. Stress can send your stomach into a painful tailspin, causing cramps, spasms and grumbling. But trouble in the gut can also affect the brain. This two-way relationship may be an unlikely key to solving one of medicine’s most pressing — and perplexing — mysteries: autism. Nearly 60 years after the disorder was first identified, the number of cases has surged, and the United Nations estimates that up to 70 million people worldwide fall on the autism spectrum. Yet there is no known cause or cure. But scientists have found promising clues in the gut. Research has revealed striking differences in the trillions of bacteria — a.k.a., the microbiome — in the intestines of children with and without autism. But the gut bacteria in individuals with autism aren’t just different. Researchers at the California Institute of Technology have shown for the first time that they may actually contribute to the disorder. They reported in the journal Cell in December 2013 that an experimental probiotic therapy alleviated autism-like behaviors in mice and are already planning a clinical trial. Today autism is treated primarily through behavioral therapy. But the new study suggests that treatment may one day come in the form of a probiotic — live, beneficial bacteria like those found in yogurt. “If you block the gastrointestinal problem, you can treat the behavioral symptoms,” Paul Patterson, a professor of biology at Caltech who co-authored the study told SFARI.org. University of Colorado Boulder professor Rob Knight hailed the finding as “groundbreaking” in a commentary in Cell. © OZY 2017 Terms & Conditions
By Claudia Wallis Dinosaurs, Star Wars, train schedules, Disney princesses, maps, LEGO—subjects such as these can become all-consuming passions for children on the autism spectrum. What therapists and educators often call “circumscribed” or “restricted” interests (or, more generously, “special” interests) make up a characteristic symptom of autism spectrum disorder (ASD). The current edition of psychiatry’s Diagnostic and Statistical Manual of Mental Disorders describes them as “highly restricted, fixated interests that are abnormal in intensity or focus.” Roughly 90 percent of high-functioning kids with ASD display at least one such interest during their elementary school years, according to a 2007 survey conducted at the Yale University Child Study Center, one of the few studies to have examined the topic. For a family with an affected child, this kind of narrow preoccupation can be tedious and exhausting. Imagine a kid who will talk about nothing but the exits on the New Jersey Turnpike or the Captain Underpants book series. (Both actual examples.) Therapists and educators have traditionally tried to suppress or modulate a child’s special interest, or use it as a tool for behavior modification: Keep your hands still and stop flapping, and you will get to watch a Star Wars clip; complete your homework or no Harry Potter. But what if these obsessions themselves can be turned into pathways to growth? What if these intellectual cul-de-sacs can open up worlds? That is the idea explored in the film Life, Animated, a contender for the Academy Award for Best Documentary this Sunday night. © 2017 Scientific American
Link ID: 23277 - Posted: 02.24.2017
Jon Brock What if I told you that we can now identify babies who are going to develop autism based on a simple brain scan? This, in essence, is the seductive pitch for a study published last week in the journal Nature, and making headlines around the world. Early identification and diagnosis is one of the major goals of autism research. By definition, people with autism have difficulties with social interaction and communication. But these skills take many years to develop, even in typically developing (i.e., non-autistic) children. Potential early signs of autism are extremely difficult to pick out amidst the natural variation in behaviour and temperament that exists between all babies. A brain scan for autism would be a major step forward. But is the hype justified? Are we really on the brink of a new era in autism diagnostics? Without wishing to detract from the efforts of everyone involved in the study, it’s important to look at the results critically, both in terms of the scientific findings and their potential implications for clinical practice. The study, led by Heather Cody Hazlett at the University of North Carolina, was part of a larger research program investigating the development of babies who have an older sibling with autism. Because autism runs in families, these babies are much more likely to develop autism than babies from the general population.
Patricia Neighmond Many men over 65 with low testosterone levels say their sense of well-being, not to mention sexual function, isn't what it used to be. That's why some doctors prescribe testosterone replacement. But the effectiveness of testosterone has been controversial. Studies of the risks and benefits have been mixed, and the Food and Drug Administration beefed up its warnings about cardiac side effects of testosterone supplementation in 2015. And the findings of five studies released Tuesday aren't likely to clear up the confusion. They appear in JAMA, the journal of the American Medical Association and JAMA Internal Medicine. The studies are collectively called the Testosterone Trials (TTrials) and they compared a testosterone gel, AndroGel, against a placebo. The results are based on 788 men with below normal levels of testosterone studied at 12 sites across the country over a year. Overall, researchers saw improvements in bone density and bone strength in men who used a testosterone gel, which raised their testosterone to levels seen in younger men. In men with unexplained anemia, testosterone also improved iron levels in the blood. (A reviewer of the study raised questions about whether it was done ethically.) But in men using testosterone who had been reporting memory problems at the start of the study, there were no improvements in memory or cognition. And there were worrisome signs of an increase in the risk of cardiovascular problems. © 2017 npr
Ewen Callaway Researchers have no way to tell whether young babies may later be diagnosed with autism. But brain scans could help, a small study suggests. By scanning the brains of babies whose siblings have autism, researchers say they have been able to make reasonably accurate forecasts about which of these high-risk infants will later develop autism themselves. The findings raise the prospect of diagnosing autism spectrum disorder (ASD) months before children develop symptoms, a goal that has proved elusive. Nature looks at the new study and its implications. Why has it been so tough to diagnose autism in infants? Children typically show symptoms of ASD, such as difficulty making eye contact, after the age of 2. Researchers believe that the brain changes underlying ASD begin much earlier — possibly even in the womb. But behavioural assessments haven't been helpful in predicting who will get autism, says Joseph Piven, a psychiatrist at the University of North Carolina (UNC) in Chapel Hill, who co-led the study, published online in Nature1. “Children who end up with autism at 2 or 3, they don’t look like they have autism in the first year," he says. Certain rare mutations are linked to ASD, but the vast majority of cases cannot be pinned to a single or even a handful of genetic risk factors. Beginning in the 1990s, Piven and other researchers noticed that children with autism tended to have larger brains than developmentally normal children, suggesting that brain growth could be a biomarker for ASD. But Piven and colleague Heather Cody Hazlett, a psychologist at UNC-Chapel Hill, say it had not been clear when overgrowth occurred. What did their latest study look at? © 2017 Macmillan Publishers Limited,
By Jesse Singal Those who advocate for sound, evidence-based research about autism are extremely alarmed about Donald Trump, and for good reason: In addition to Trump’s ties to Andrew Wakefield, the disgraced British doctor whose debunked research helped fuel the false idea of links between childhood vaccines and autism, Robert F. Kennedy Jr., a notorious anti-vaxxer himself, told reporters back in January that Trump planned to tap him as chair of a commission on “vaccine safety.” There is no question at this point that Trump has significant connections to a pseudoscientific medical movement that spreads dangerous, disproven ideas. Today, Trump gave nervous observers yet more reason to worry. It occurred at a White House event in which Trump and Secretary of Education Betsy DeVos met with a bunch of educators. Trump seemed to fixate, for a moment, on one educator named Jane (her last name is hard to make out) after she explained that she is the principal of a special education center in Virginia. The sequence starts at about 5:38 in this video: After Jane noted that many of her students have autism, Trump asked, “Have you seen a big increase in the autism, with the children?” Jane replied in the affirmative, but seemed to couch her response as being more about an increase in demand for services — she didn’t explicitly agree there’s been a big increase in the overall rate. Trump continued: “So what’s going on with autism? When you look at the tremendous increase, it’s really — it’s such an incredible — it’s really a horrible thing to watch, the tremendous amount of increase. Do you have any idea? And you’re seeing it in the school?” Jane replied — again, in a way that seems a bit noncommittal vis-à-vis Trump’s claim — that the rate of autism is something like 1-in-66 or 1-in-68 children. To which Trump responds: “Well now, it’s gotta be even lower [presumably meaning higher, rate-wise] than that, which is just amazing — well, maybe we can do something.” (Jane had the rate right, and Trump is incorrect that it has crept higher.) © 2017, New York Media LLC.
Link ID: 23233 - Posted: 02.15.2017
Having a thicker outer layer of the brain is linked to an increased likelihood of having autism. The cerebral cortex is the wrinkled outer layer of the brain that is responsible for many of our most human traits, including thought, language and consciousness. This layer is typically thicker in men than in women, and its structure has been linked to differences in personality. Now brain scans have shown that women who have a more male-like brain structure are three times more likely to have been diagnosed with autism. The study compared the brains of 98 men and women with high functioning autism with those of 98 people who don’t have autism. These findings provide new insights into the brain’s role in sex differences in autism, according to the team that did the study. Autism is thought to be two to five times more common in men than in women, and some think the condition is caused by having an “extreme male brain”. Journal reference: JAMA Psychiatry, DOI: 10.1001/jamapsychiatry.2016.3990 © Copyright Reed Business Information Ltd.
In the mood? Feeling sexy and romantic has been linked to a hormone named kisspeptin. Researchers hope the chemical may help treat people with some sexual problems. Kisspeptin occurs naturally in the body, where it stimulates the release of other signalling chemicals that have been linked to reproduction. Now a study of 29 heterosexual young men has found that injections of the hormone enhance the brain’s response to sexual and romantic pictures of couples. After injection, MRI scans showed increased activity in the regions of the brain that are usually stimulated by sexual arousal and romance. But this activity was only prompted by arousing pictures – non-sexy images did not have the same effect. “Our findings indicate that kisspeptin could play a role in stimulating some of the emotions and responses that lead to sex and reproduction,” says Waljit Dhillo, at Imperial College London. “Ultimately, we are keen to look into whether kisspeptin could be an effective treatment for psychosexual disorders.” The team now plans to study the effects of the hormone in a larger group of people, including women as well as men. Journal reference: Journal of Clinical Investigation © Copyright Reed Business Information Ltd.
By Kevin Pelphrey, In September, the Florida State University football team made a visit to a Tallahassee middle school that would become famous. At lunchtime, student-athlete Travis Rudolph noticed sixth grader Bo Paske eating alone, so he joined Bo for the meal. Bo, who has autism, often sat by himself in the lunchroom. The world took note of the athlete’s gesture after his mother’s Facebook post about it went viral. “This is one day I didn’t have to worry if my sweet boy ate lunch alone, because he sat across from someone who is a hero in many eyes,” she wrote. This story touched people because it calls to mind something universal: the sting of social exclusion. We have all known children who often eat, or play, alone. And all of us have felt left out at one time or another. But although this experience may be universal, a new generation of children is experiencing a wave of inclusiveness. Technology of various types, often thought of as an isolating influence, can actually abet people’s good intentions or help those with autism learn to fit in. One new app called Sit With Us, invented by 16-year-old Natalie Hampton, helps vulnerable children who have difficulty finding a welcoming group in the lunchroom. Its motto is inspiring: “The first step to a warmer, more inclusive community can begin with LUNCH.” Sit With Us allows students to designate themselves as ‘ambassadors’ and to signal to anyone seeking company that they’re invited to join the ambassador’s table. © 2017 Scientific American
By LISA SANDERS, M.D. “You don’t look well,” the man at the gas station told the older woman in the car. He’d known her for years, always thinking of her as a lively, robust woman. But that day she looked pale and tired. Her sharp blue eyes seemed dim. She gave a feeble smile. “I don’t feel well at all,” she told him. There’s an urgent-care clinic just up the street, he said. Could she make it there? She was nearly 45 minutes away from her home in Halifax, Nova Scotia. Stopping just up the street seemed a much better option. At the clinic, the doctor took one look at her, put a blood pressure cuff around her arm and told her assistant to call an ambulance. The rest of the day was a blur. The woman remembers being bundled onto a stretcher and one of the E.M.T.s saying her blood pressure was very low. It was an odd thing to hear, because her blood pressure was usually high enough to require three medications. She was taken to the emergency room at the Queen Elizabeth II Health Sciences Center in Halifax. She remembers being fussed over — having blood drawn, receiving intravenous fluids, feeling sticky snaps being placed on her chest that connected her to a continuous heart monitor. She had been a nurse for many years when she was younger, yet seeing herself at the center of these familiar activities was strange. A blood test indicated that there may have been damage to her heart. The doctor told her she was having a heart attack, she recalls. You’ve got the wrong patient, she thought to herself. Sure, she had a little high blood pressure, a little asthma, a little back pain. But problems with her heart? Never. The patient used a cane, but she had no difficulty getting up on the exam table — an important test of mobility. © 2017 The New York Times Company
Keyword: Hormones & Behavior
Link ID: 23101 - Posted: 01.14.2017
By Andy Coghlan Can tiny brains grown in a dish reveal the secrets of sociability? Balls of brain tissue generated from stem cells are enabling us to understand the underlying differences between people who struggle to be sociable and those who have difficulty reining themselves in. Alysson Muotri at the University of California, San Diego, and his team created the mini-brains by exposing stem cells taken from the pulp of children’s milk teeth to cocktails of growth factors that help them mature. Eventually, they can develop as many as six layers of cerebral cortex – the outer surface of the brain. This region is much more sophisticated in humans than in other animals, and houses important circuitry governing our most complex thoughts and behaviours, including socialising with others. Each mini-brain is approximately 5 millimetres across. “Though they’re not as well defined as they are in a real brain, they resemble what you find in an embryonic fetus,” says Muotri. To understand how brain development affects sociability, the team used donated cells from children with autism and Rett syndrome, both of which are associated with impaired communication skills. They also used cells from children with Williams syndrome, a condition characterised by a hyper-sociable nature. People with Williams syndrome can be unable to restrain themselves from talking to complete strangers. © Copyright Reed Business Information Ltd.
By Andy Coghlan Is the fabled “cuddle hormone” really a “warmone”? Oxytocin levels surge in troops of chimpanzees preparing for conflict with rival groups to defend or expand their territory. The finding is at odds with the prevailing image of oxytocin as something that helps strengthen bonds between parent and infant, or foster friendships. But given its capacity to strengthen loyalty, oxytocin could also be a warmonger hormone that helps chimps galvanise and cooperate against a common enemy. Catherine Crockford of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and her colleagues monitored two rival groups of chimpanzees in the Taï National Park in Ivory Coast, each containing five males and five females, for prolonged periods between October 2013 and May 2015. Thanks to trust built up between the team and the chimps, the team could safely track and video the groups – even during conflict, observing at close quarters what was happening. Crucially, the team was also able to pipette up fresh samples from soil when chimps urinated. The samples revealed that oxytocin levels surge in the mammals whenever the chimps on either side prepared for confrontation, or when either group took the risk of venturing near or into rival-held territories. These surges dwarfed the oxytocin levels seen during activities such as grooming, collaborative hunting for monkey prey or food sharing. © Copyright Reed Business Information Ltd.
By Kevin McCarthy There’s a dearth of safety data for melatonin, but there are a number of potential concerns, especially for children. “I think we just don’t know what the potential long-term effects are, particularly when you’re talking about young children,” said Dr. Judith Owens, director of the Center for Pediatric Sleep Disorders at Boston Children’s Hospital. “Parents really need to understand that there are potential risks.” The pineal gland in the brain ramps up production of the hormone melatonin in the evening, as light fades, to encourage sleep, and it turns down production in the early morning hours. Synthetic forms of the hormone are also sold as a dietary supplement; because melatonin is found in some foods, like barley, olives and walnuts, it is regulated as a nutritional supplement rather than a drug, as most other hormones are. In adults, studies have found melatonin to be effective for jet lag and some sleep disorders. It is also hugely popular as a sleep aid for children and can be useful for sleep disorders among those with attention-deficit disorders or autism, Dr. Owens said. “I rarely see a family come in with a child with insomnia who hasn’t tried melatonin,” she said. “I would say at least 75 percent of the time when they come in to see us” at the sleep clinic, “they’re either on melatonin or they’ve tried it in the past.” While short-term use of the hormone is generally considered safe, it can have side effects, including headaches, dizziness and daytime grogginess, which could pose a risk for drivers. Melatonin can also interfere with blood pressure, diabetes and blood thinning medications. © 2017 The New York Times Company
National Institutes of Health (NIH) researchers have discovered molecular mechanisms that may underlie a woman’s susceptibility to disabling irritability, sadness, and anxiety in the days leading up to her menstrual period. Such premenstrual dysphoric disorder (PMDD) affects 2 to 5 percent of women of reproductive age, whereas less severe premenstrual syndrome (PMS) is much more common. “We found dysregulated expression in a suspect gene complex which adds to evidence that PMDD is a disorder of cellular response to estrogen and progesterone,” explained Peter Schmidt, M.D. of the NIH’s National Institute of Mental Health, Behavioral Endocrinology Branch. “Learning more about the role of this gene complex holds hope for improved treatment of such prevalent reproductive endocrine-related mood disorders.” Schmidt, David Goldman, M.D., of the NIH’s National Institute on Alcohol Abuse and Alcoholism, and colleagues, report on their findings January 3, 2017 in the journal Molecular Psychiatry. “This is a big moment for women’s health, because it establishes that women with PMDD have an intrinsic difference in their molecular apparatus for response to sex hormones – not just emotional behaviors they should be able to voluntarily control,” said Goldman. By the late 1990s, the NIMH team had demonstrated (link is external) that women who regularly experience mood disorder symptoms just prior to their periods were abnormally sensitive to normal changes in sex hormones — even though their hormone levels were normal. But the cause remained a mystery.