Links for Keyword: Hormones & Behavior

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THERE was at least one downside to Farinelli's castration. The operation may have preserved the 18th-century singer's treble voice into adulthood, making him a musical legend, but it also condemned him to a skull deformity that may have affected his mind. Farinelli was exhumed in 2006 so that his skeleton could be studied. Lead investigator Maria Giovanna Belcastro of the Alma Mater Studiorum University of Bologna, Italy, was able to identify two unusual features. Like those of other castrati, Farinelli's limb bones were unusually long. And the front of his skull had grown inwards in a lumpy mass, in places twice as thick as unaffected bone (Journal of Anatomy, DOI: 10.1111/j.1469-7580.2011.01413.x). This is called hyperostosis frontalis interna (HFI). It is thought to be caused by hormonal disorders, particularly too much oestrogen, which explains why it is normally found in post-menopausal women and is rare in men. HFI was thought to be harmless, says Israel Hershkovitz of Tel Aviv University in Israel, but is now linked to behavioural disorders, headaches and neurological diseases like Alzheimer's. Though any such symptoms probably would not have affected Farinelli until late in life, Hershkovitz says. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 15607 - Posted: 07.26.2011

by Elizabeth Norton Life for those with a genetic disease called Prader-Willi syndrome, which affects an estimated one out of 15,000 people, can be challenging both for the patient and his or her family. Sufferers have an insatiable hunger that can lead to life-threatening obesity if access to food is not restricted. And worse, they have behavioral problems akin to autism. Tantrums and tears are common because these patients have difficulty understanding the motives of others and controlling their own emotions. But treatment with the brain hormone oxytocin may help bring both emotions and eating into balance, according to a new study. Several clues pointed to the potential of oxytocin, often thought of as the "trust hormone." Research conducted on the brain tissue donated after death from Prader-Willi patients showed that the hypothalamus (the body's thermostat) has abnormalities in the nerve cells that produce this hormone. Moreover, the hypothalamus releases oxytocin in response to touching, social interactions, relaxation, and trust—all the things people with Prader-Willi syndrome have trouble with. And oxytocin treatments have improved the social skills of autistic patients. Finally, the hormone is thought to contribute to feelings of fullness after eating, "satiety" in scientific parlance. To see whether oxytocin could benefit individuals with Prader-Willi syndrome, endocrinologist Maïthé Tauber of the Children's Hospital in Toulouse, France, and colleagues injected oxytocin or a placebo into the noses of 24 adult patients. The researchers monitored the patients' behavior; they also used cartoon stories to test patients' grasp of social interactions and pictures of faces to see how well they could recognize emotions. © 2010 American Association for the Advancement of Science

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 15485 - Posted: 06.25.2011

By KATHRYN HARRISON Readers who can’t identify Jean-Martin Charcot as the name of the French neurologist whose 19th-century experiments with hypnosis influenced Sigmund Freud’s theory of neurosis may yet recognize the work he conducted at the Saltpêtrière Hospital in Paris. Photographs and illustrations of Charcot’s patients, all women suffering hysteria, remain in currency today, 140 years after they were made, if more as curiosities than as clinically valuable documents. Once seen, these images — of, for example, a woman wearing little more than a tangle of bed sheets, her eyes rolled up into her head in either “ecstasy” or “delirium,” or fixed on the invisible object of her “amorous supplication” — are not easily forgotten, let alone dismissed. Poses classified as “passionate attitudes,” they have the disquieting aspect of pornography masquerading as intellectual inquiry. Charcot, as portrayed in Asti Hust­vedt’s consistently enthralling “Medical Muses,” focused intently — myopically, one could argue — on using hypnosis to induce hysteria and make “his hysterics, with their bizarre fits and spasms, into ideal medical specimens.” But the provocative behavior of those “specimens” transformed Saltpêtrière into something closer to a carnival than a teaching hospital. As much showman as physician, Charcot gave weekly two-hour lectures to a packed amphitheater, including demonstrations designed to captivate an audience accustomed to staged séances and exhibitions of mesmerism or telepathy. One of Charcot’s students described the dramatic potential of exhibiting hypnotized women: “We can cut them, prick them and burn them, and they feel nothing.” © 2011 The New York Times Company

Related chapters from BP7e: Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 15460 - Posted: 06.20.2011

FOR people worried about the feminising effect of oestrogen-like chemicals in the water there is now a modern-day equivalent of the canary in the coal mine: a genetically modified fish in a bowl. Male fish exposed to oestrogen have delayed sperm development and grow smaller testes. Some industrial chemicals, such as bisphenol A, mimic oestrogen, but little is known about how the effects of different oestrogen-like chemicals add up in water. To find out, Xueping Chen and colleagues at Vitargent, a biotechnology company in Hong Kong, have created a genetically engineered fish that glows green when it is exposed to oestrogen-like chemicals. Chen's team took the green fluorescent protein gene from jellyfish and spliced it into the genome of the medaka fish, Oryzias melastigma, next to a gene that detects oestrogen. Chemicals that have oestrogen-like activity cause the fish to express the modified gene, making them glow. When the team tested the fish at eight sites around Hong Kong, they found that some chemicals that showed weak or no oestrogenic activity, including UV filters used in sunscreen, had combined in water to amplify or create an oestrogenic effect. The work is as yet unpublished. William Price of the University of Wollongong in New South Wales, Australia, warns the approach does not detect a biological response. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 15415 - Posted: 06.11.2011

By LISA SANDERS, M.D. A fiercely independent and active 76-year-old woman spent the past decade caring for her aged mother, who died at 99. Weeks after her mother’s death, the woman collapsed at home. She was found to have bleeding from a collection of abnormal blood vessels (known as AVMs, or arteriovenous malformations) in her colon. In the months after, the patient’s red-blood-cell count returned to normal, but she never regained her old energy and strength. She told her daughters that she was weaker and more tired than she had ever been in her life. Dr. Susan Wiskowski, a family physician in Hartford, was the woman’s doctor. Until recently, the patient was in good health for her age, with only a few medical problems: high blood pressure, which was controlled with one medication; hypothyroidism, treated with Synthroid; and cataracts, which had been surgically repaired. Now, out of the blue, she was experiencing rapid weight gain, swelling and weakness in her legs, which made it hard to walk. A couple of weeks after the cardiac work-up, the patient’s behavior became erratic and strange. Despite her complaints of weakness, she veered between bursts of activity — endlessly cleaning her house, giving large dinner parties — and days of isolation and fatigue. She was sometimes elated, telling her four daughters that she’d found where heaven was located. She began to talk about giving away her possessions. One afternoon she seemed completely out of control. A neighbor called 911, and the patient was rushed by ambulance to St. Francis Hospital in Hartford. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 15297 - Posted: 05.07.2011

By Amina Zafar, CBC News The role estrogen plays in women's brains remains murky but researchers are beginning to clarify it. The first Women's Brain Health Academic Symposium in Toronto on Wednesday brought together experts from North America leading a discussion about trying to better understand the female brain. "Seventy per cent of Alzheimer's patients are women," said Lynn Posluns, founder and chair of the Women of Baycrest, which aims to raise $5 million for a research chair devoted to women's brain health. Researchers want to uncover exactly how estrogen affects different regions of the female brain.Researchers want to uncover exactly how estrogen affects different regions of the female brain. Brian Snyder/Reuters Yet most laboratory studies today are done on male rats because female rats are considered too complex, Posluns said. "I'm saying there's a real disconnect here. It is time for scientists to better understand the female brain." At the symposium, Gillian Einstein, a professor of psychology and public health at the University of Toronto, talked about her early findings exploring the role of estrogen on brain functions such as mood and memory. "I want women to be circumspect about the effect of their hormones on their mood and cognition," said Einstein. "It may or may not be PMS that makes you grumpy. It's possible that your husband really did do something crappy, and you have a reasonable response to it. [On the other hand] I also think it's important to think they may be having an effect." © CBC 2011

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 13: Memory, Learning, and Development
Link ID: 15191 - Posted: 04.07.2011

CONJURE up an image of a financial risk-taker, and you'll probably picture an aggressive Wall Street trader, testosterone surging as he closes the deal. But new research suggests that people with low levels of the male sex hormone are also likely to take financial risks. Previous studies have linked high levels of testosterone to certain risk-seeking behaviours. To investigate whether financial risk-taking follows a similar pattern, Scott Huettel at Duke University in Durham, North Carolina, measured the testosterone levels of 298 people, who then took part in trials in which they chose between a fixed known reward or a gamble between getting a payout - mostly larger than the fixed reward - or nothing. Overall, the volunteers generally preferred the known return than the gamble, even if they would have been better off, on average, by taking a chance. Surprisingly, the biggest risks were taken by people with very high or very low testosterone, compared with the average levels for their gender (Psychological Science, DOI: 10.1177/0956797611401752). Economists want to predict who is likely to be successful at playing financial markets, says Dario Mastripieri at the University of Chicago. "It's legitimate to ask if biology is going to have an effect." © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 15118 - Posted: 03.21.2011

by Wendy Zukerman Is it that time of the month? These are the words no man should ever utter. How about this for a diplomatic alternative: "Are your GABA receptors playing up?" You may be spot on. It seems that these brain cells are to blame for some women's monthly mood swings. Many women feel a little irritable before menstruating, but up to 8 per cent suffer extreme symptoms, including anxiety, depression and fatigue. Symptoms of what's called premenstrual dysphoric disorder (PMDD) begin around a week before menstruation when women are in the "late luteal phase" of their cycle and progesterone levels are at their height. Symptoms quickly subside after menstruation, once the so-called "follicular phase" has kicked in. To investigate potential mechanisms behind PMDD, Andrea Rapkin at the University of California, Los Angeles used a PET scan, which shows where glucose is being metabolised to identify activity in the brain. The idea was to analyse the brain activity of 12 women with PMDD and 12 without the condition, at various times throughout their menstrual cycle. Before each scan, the women rated the severity of any symptoms they had on a scale of one to six. Blood samples were also taken to test their hormone levels. Fluctuating hormones were not to blame: all the women experienced similar jumps in progesterone levels throughout their cycle, irrespective of whether they had PMDD or not. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 15002 - Posted: 02.15.2011

By Bruce Bower SAN ANTONIO — Oxytocin, a hormone with a rosy reputation for getting people to love, trust and generally make nice with one another, can get down and dirty, according to evidence presented on January 28 at the annual meeting of the Society for Personality and Social Psychology. This brain-altering substance apparently amplifies whatever social proclivities a person already possesses, whether positive or negative, says psychologist Jennifer Bartz of Mount Sinai School of Medicine in New York City. Previous work has shown that a nasal blast of the hormone encourages a usually trusting person to become more trusting (SN Online: 5/21/08), but now Bartz and her colleagues find that it also makes a highly suspicious person more uncooperative and hostile than ever. “Oxytocin does not simply make everyone feel more secure, trusting and prosocial,” Bartz says. These new results raise concerns about plans by some researchers to administer oxytocin to people with autism and other psychiatric conditions that include social difficulties, she adds. Her team studied 14 people diagnosed with borderline personality disorder and 13 volunteers with no psychiatric conditions. Symptoms of borderline personality disorder include severe insecurity about relationships, fears of abandonment and constant, needy reassurance-seeking from partners. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 14942 - Posted: 02.01.2011

By NICHOLAS BAKALAR A new study suggests that a widely prescribed antidepressant may provide at least some relief for women with hot flashes. Hormone replacement therapy is now the only treatment approved by the Food and Drug Administration for menopausal symptoms, but many believe its risks outweigh its benefits. This study, published Thursday in The Journal of the American Medical Association, was a randomized, double-blinded, placebo-controlled trial of escitalopram (brand name Lexapro) in which 97 menopausal women took the drug for eight weeks while a matched group took a placebo. Just over half of the women in the treatment group reported a decrease of at least 50 percent in the frequency of hot flashes; 36 percent did in the placebo group. Women taking escitalopram averaged 1.41 fewer hot flashes per day than in those on the placebo, and there were no serious side effects. And almost two-thirds of the treatment group wanted to continue the medication, compared with 42 percent of the others. The lead author, Ellen W. Freeman, a professor of obstetrics and gynecology at the University of Pennsylvania, stressed that this is an off-label use of the drug not approved by the F.D.A. Still, she said, “it provides an option, and there’s not much out there that has been shown to be effective.” © 2011 The New York Times Company

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 14914 - Posted: 01.25.2011

By NICHOLAS WADE Oxytocin has been described as the hormone of love. This tiny chemical, released from the hypothalamus region of the brain, gives rat mothers the urge to nurse their pups, keeps male prairie voles monogamous and, even more remarkable, makes people trust each other more. Yes, you knew there had to be a catch. As oxytocin comes into sharper focus, its social radius of action turns out to have definite limits. The love and trust it promotes are not toward the world in general, just toward a person’s in-group. Oxytocin turns out to be the hormone of the clan, not of universal brotherhood. Psychologists trying to specify its role have now concluded it is the agent of ethnocentrism. A principal author of the new take on oxytocin is Carsten K. W. De Dreu, a psychologist at the University of Amsterdam. Reading the growing literature on the warm and cuddly effects of oxytocin, he decided on evolutionary principles that no one who placed unbounded trust in others could survive. Thus there must be limits on oxytocin’s ability to induce trust, he assumed, and he set out to define them. In a report published last year in Science, based on experiments in which subjects distributed money, he and colleagues showed that doses of oxytocin made people more likely to favor the in-group at the expense of an out-group. With a new set of experiments in Tuesday’s issue of the Proceedings of the National Academy of Sciences, he has extended his study to ethnic attitudes, using Muslims and Germans as the out-groups for his subjects, Dutch college students. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 14855 - Posted: 01.11.2011

Ed Yong There’s a chemical that can subtly shift your childhood memories of your own mother. In some people, it paints mum in a more saintly light, making them remember her as closer and more caring. In others, the chemical has a darker influence, casting mum as a less caring and more distant parent. All of this becomes heavily ironic when you consider that the chemical in question – a hormone called oxytocin – is often billed as the “hormone of love”, and even marketed as “Liquid Trust”. As a new study shows, the reality is much more complicated. Describing oxytocin as the “hormone of love” is like describing a computer as a “writing tool” – it does other things too, some of which aren’t pleasant. Oxytocin is a versatile actor, whose resume includes all sorts of jobs in sex, reproduction, social behaviour and emotions. It can increase trust among people and make them more cooperative (this works in meerkats, too). It can increase the social skills of autistic people. It’s released during orgasm. It affects lactating breasts, contracting wombs and the behaviour of sheep mothers towards their newly born lambs. The list goes on: drug addiction, generosity, depression, empathy, learning, memory. Despite these many roles, oxytocin is often reduced to a misleading label. While “hormone of love” may be great for catchy headlines and compelling marketing slogans, they are ultimately misleading. Jennifer Bartz from the Mount Sinai School of Medicine has found that oxytocin can have completely opposite effects on the way people behave, depending on how they view their relationships to other people. © 2010, Kalmbach Publishing Co.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 14714 - Posted: 11.30.2010

By Helen Briggs Health reporter, BBC News Sex hormones taken by women after the menopause may make their brains "younger", researchers claim. A small study of post-menopausal women found those on HRT performed better in tests measuring how the left and right hand sides of the brain work together. Psychologists at Durham University say it mirrors the brain activity of younger women who naturally produce the sex hormones in their bodies. The research is published in the journal Hormones and Behavior. The study involved 62 post-menopausal women aged between 46 and 71. Of these, 36 were on hormone therapy, while the rest were in the control group. All were right-handed. They were asked to carry out fine motor coordination tasks, such as tapping buttons with different fingers using both their left and right hands. The researchers say both hands performing together equally was a sign that the two brain halves were interacting more. This was found to be more pronounced in the women on HRT. BBC © MMX

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 14709 - Posted: 11.27.2010

By Amanda Chan If you're a guy who finds it hard to talk about your feelings, the problem might lie with your testosterone levels, a recent study suggests. A psychological condition called alexithymia is found in people who have an extraordinarily difficult time conveying emotions to others and interpreting others' feelings. Past studies have shown that alexithymia and depression are closely related, and the condition has long been associated with aging. Depression, low testosterone and erectile dysfunction are all known to become more common in men as they age. Researchers from Finland wanted to see if alexithymia is a result of aging itself, or if it is actually caused by other factors that typically come with aging, like a lower sex drive. In the study, nearly 1,400 men ages 25 to 65 filled out questionnaires during a three-year period, beginning in 1998, and reported difficulties they had in expressing thoughts and emotions, symptoms of depression and general life-satisfaction levels. Out of those 1,400 men, researchers chose 116, half who had symptoms of alexithymia and half who did not, and asked them to complete a follow-up survey and report their alcohol intake, smoking status, and other information, and were also given a blood test to check their testosterone levels, said study researcher Kirsi Honkalampi, a professor at the Kuopio Psychiatric Center in Finland. MyHealthNewsDaily Copyright © 2010.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 14579 - Posted: 10.21.2010

By Craig H. Kinsley and Elizabeth A. Meyer It seems that weekly we hear about some professional athlete who sullies himself and his sport through abuse of steroids. The melodrama unfolds, careers and statistics are brought low and asterisked, and everyone bemoans another fallen competitor. Yet there are millions of cases of steroid use that occur daily with barely a second thought: Millions of women take birth control pills, blithely unaware that their effects may be subtly seeping into and modulating brain structure and activity. It is a huge experiment whose resolution will not be known for a while, but a new study in the journal Brain Research demonstrates that the effects are likely to be dramatic. It found that birth control pills have structural effects on regions of the brain that govern higher-order cognitive activities, suggesting that a woman on birth control pills may literally not be herself -- or is herself, on steroids. The human brain is a remarkable structure, not least because of its seemingly infinite capacity for change, adapting millisecond by millisecond. Indeed, a structure with tens of billions of neurons, each of which has the ability to elaborate and branch and become more complex, while changing its activity in the process, is the very definition of change. This so-called neuroplasticity is a hallmark of the nervous system. It can, however, be augmented, boosted, by artificial means, and if we are not careful, the brain may go all catawampus. Steroid hormones, which are excreted by endocrine organs such as testes and ovaries, flow in abundance throughout the bloodstream, reach target organs and structures, and exert powerful effects on them. To wit, the cock’s comb, the buck’s antlers, the lion’s mane, the blood-engorged uterus. © 2010 Scientific American,

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 13: Memory, Learning, and Development
Link ID: 14505 - Posted: 09.30.2010

Content provided by AFP High estrogen levels in women while they are ovulating may be directly responsible for sluggishness or problems concentrating, a Canadian study released Friday has found. Researchers at Concordia University's Center for Studies in Behavioral Neurobiology in Montreal linked high estrogen levels in laboratory rats to an inability to pay attention and learn. These high levels have also been shown to interfere with women's ability to pay attention, but the study, to be published in the journal Brain and Cognition, is the first to show "how this impediment can be due to a direct effect of the hormone on mature brain structures," said a statement. Both humans and rodents have similar brain physiology. "Although estrogen is known to play a significant role in learning and memory, there has been no clear consensus on its effect," said study lead author Wayne Brake. "Our findings...show conclusively that high estrogen levels inhibit the cognitive ability in female rodents." Researchers repeatedly exposed rats to a tone, with no consequences. Once they became used to it and ignored it, another stimulus was linked to the tone. © 2010 Discovery Communications, LLC.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 17: Learning and Memory
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 13: Memory, Learning, and Development
Link ID: 14501 - Posted: 09.28.2010

Tim Kiladze A chief executive officer’s patience and co-operation can make or break a corporate merger or acquisition. That’s no secret. But researchers at the University of British Columbia’s Sauder School of Business now offer a biological explanation for male CEOs’ willingness, or lack thereof, to negotiate: testosterone levels. The UBC team crunched the numbers for 350 corporate deals completed between 1997 and 2007 and determined that the aggression-causing hormone directly affects a male CEO’s tendency to bid for a company – and to walk away from an unfavourable deal. “Normally, assets should go to buyers that value [them] the most,” finance professor and lead researcher Maurice Levi said, “if decisions are based purely on the basis of rationality.” However, his team found that hormones intervene and make CEOs bid for things they don’t necessarily need, or turn down offers out-of-hand, without trying to negotiate better terms. “They might be pursuing things that give them the most dominance, but do not give them the most value,” Mr. Levi said. Notably, men with higher testosterone levels are 20 per cent more likely to walk away from a takeover offer. They are also 4 per cent more likely to make takeover bids, a small effect but still statistically significant. The Sauder study was based on a 2007 Harvard University experiment in which pairs of male participants tried to make a deal to split $40. Participants with above-average testosterone levels, tested in a laboratory, were more likely to reject a lowball offer, whereas those with below-average levels were less likely to drive a hard bargain. © Copyright 2010 CTVglobemedia Publishing Inc.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 11: Emotions, Aggression, and Stress
Link ID: 14449 - Posted: 09.14.2010

By Janet Raloff Cash register and other receipts may expose consumers to substantial amounts of bisphenol A, a hormone-mimicking chemical that has been linked with a host of potential health risks, according to a trio of recent studies. Each study offers preliminary evidence that a large number of retail outlets print sales receipts on certain types of heat-sensitive, or thermal, paper that use BPA as a color developer. Two of the new studies also showed that the BPA coating easily rubs off onto fingers. And one found evidence that BPA from receipts may penetrate skin. The pollutant, which mimics the biological activity of estrogen, has been tied to health risks from behavioral problems in children to obesity and heart ailments. In animals, exposures in the womb put moms and their offspring at risk for later metabolic diseases. Based on growing concern about possible risks from ubiquitous exposure to BPA, especially in children, the federal government recently issued warnings to parents about where their families were most likely to encounter the chemicals. Store receipts did not make the list, although there have been hints for years that thermal receipt paper could be a rich source. Chemist John Warner learned about the chemistry of thermal- and pressure-sensitive papers while working for Polaroid years ago. Manufacturers lay a powdery coating containing BPA, a dye and a solvent onto one side of a piece of paper. When heat or pressure is applied, the coating’s constituents merge to release the ink’s color, he explains. © Society for Science & the Public 2000 - 2010

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 14321 - Posted: 08.05.2010

Genetic engineers, move over: the latest scheme for creating children to a parent’s specifications requires no DNA tinkering, but merely giving mom a steroid while she’s pregnant, and presto—no chance that her daughters will be lesbians or (worse?) ‘uppity.’ Or so one might guess from the storm brewing over the prenatal use of that steroid, called dexamethasone. In February, bioethicist Alice Dreger of Northwestern University and two colleagues blew the whistle on the controversial practice of giving pregnant women dexamethasone to keep the female fetuses they are carrying from developing ambiguous genitalia. (That can happen to girls who have congenital adrenal hyperplasia (CAH), a genetic disorder in which unusually high prenatal exposure to masculinizing hormones called androgens can cause girls to develop a deep voice, facial hair, and masculine-looking genitalia.) The response Dreger got from physicians and scientists who were outraged over this unapproved use of dexamethasone caused her to dig deeper into the scientific papers of the researcher who has promoted it. The result of that digging is a discovery that is much less outrageous than the PR push, and some media coverage, would have you believe, but one that nonetheless raises important questions about gender, sexuality, and research on unknowing patients. In an essay titled “Preventing Homosexuality (and Uppity Women) in the Womb?” and posted on the bioethics forum of The Hastings Center, a think tank in Garrison, N.Y., Dreger and her colleagues pluck numerous brow-raising statements from the writings of pediatric endocrinologist Maria New of Mount Sinai Medical Center in New York, who has long promoted prenatal dexamethasone to treat CAH. But if that position is controversial (as I’ll explain below), what Dreger and her colleagues claim to have uncovered is even more so. New, they say, wants to use dexamethasone to prevent CAH girls from becoming lesbians, from rejecting motherhood, and from choosing traditionally masculine careers. © 2010 Newsweek, Inc

Related chapters from BP7e: Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases; Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 14229 - Posted: 07.06.2010

By NICHOLAS WADE The glue that binds a human society together is trust. But people who trust others too much are likely to get taken for a ride. Both trust and distrust, it now seems, are influenced by hormones that can induce people to ratchet their feeling of trust up or down. The trust side of the equation is mediated by a brain hormone known as oxytocin. A soft touch or caress will send a pulse of oxytocin into a person’s bloodstream. Swiss researchers found in 2005 that a squirt of oxytocin would make players in an investment game more willing to hand over their money to strangers. It may seem strange that there is a hormonal influence in such a delicate calculation as to whether or not to trust someone. But perhaps trust is so important to a society’s survival that natural selection has generated a hormonal basis for it. In any event, trust has a downside — one may hand over too much money to a Mr. Madoff who promises to generate steady returns in both up and down markets. There needs to be an antidote to oxytocin that makes a person keep those warm, fuzzy feelings suppressed in the appropriate circumstances. Researchers at Utrecht University in Holland now report that they have identified this antidote: it is testosterone. They gave young women a dose of the hormone in the form of a drop of liquid placed under the tongue, then asked them to judge the trustworthiness of a series of men’s faces shown in photographs. The women were significantly less inclined to trust a face when given testosterone than when they had taken a placebo, the Dutch team reported last month in The Proceedings of the National Academy of Sciences. Copyright 2010 The New York Times Company

Related chapters from BP7e: Chapter 5: Hormones and the Brain
Related chapters from MM:Chapter 8: Hormones and Sex
Link ID: 14161 - Posted: 06.24.2010