Chapter 8. Hormones and Sex

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By Elizabeth Pennisi Males resort to all sorts of desperate measures when fertile females are scarce, including banding together to guard a potential mate. Now, researchers have discovered that such bands of bottlenose dolphins may coordinate their actions with unique “popping” calls—the first evidence that animals other than humans can synchronize themselves using vocal signals. Humans often use vocal signals to coordinate actions, like marching and dancing, that reinforce unity and intimidate outside groups. The synchronized displays of other animals—like fireflies that light up at the same time—are thought to be competitive, showing off which male is the sexiest, rather than cooperative. In Shark Bay, off the coast Western Australia 800 kilometers north of Perth, groups of up to 14 male dolphins form lifelong alliances. Together, subsets of three keep close tabs on potential female mates, swimming, turning, and surfacing in unison to guard and herd them—one female at a time. Scientists watching this behavior noticed these males often emit a unique “popping” call, making series of two to 49 very short sounds, 10 per second, over and over. e dolphins popping The scientists dragged four underwater microphones behind a motorboat and recorded 172 instances in which multiple males were “popping” together (above). When the males pop alone, their timing and tempo varies. But when they pop together, they do it at the same time and at the same rate, suggesting they are using the sounds to enhance their cooperation, the team reports today in the Proceedings of the Royal Society B. This synchronized popping may be a threat, as it tends to make the female dolphin move closer to her male guards. But more importantly, the researchers say, it may help reinforce that the males need to act—and talk—as one to ensure they get their gal. © 2020 American Association for the Advancement of Science

Keyword: Sexual Behavior; Aggression
Link ID: 27156 - Posted: 04.01.2020

By Matt McGrath Environment correspondent A new study that looks at lifespan in wild mammals shows that females live substantially longer than males. The research finds that, on average, females live 18.6% longer than males from the same species. This is much larger than the well-studied difference between men and women, which is around 8%. The scientists say the differences in these other mammals are due to a combination of sex-specific traits and local environmental factors. In every human population, women live longer than men, so much so that nine out of 10 people who live to be 110 years old are female. This pattern, researchers say, has been consistent since the first accurate birth records became available in the 18th Century. While the same assumption has been held about animal species, large-scale data on mammals in the wild has been lacking, Now, an international team of researchers has examined age-specific mortality estimates for a widely diverse group of 101 species. In 60% of the analysed populations, the scientists found that females outlived the males - on average, they had a lifespan that's 18.6% longer than males. "The magnitude of lifespan and ageing across species is probably an interaction between environmental conditions and sex-specific genetic variations," said lead author Dr Jean-Francois Lemaître, from the University of Lyon, France. He gives the example of bighorn sheep for which the researchers had access to good data on different populations. Where natural resources were consistently available there was little difference in lifespan. However, in one location where winters were particularly severe, the males lived much shorter lives. © 2020 BBC.

Keyword: Sexual Behavior; Evolution
Link ID: 27137 - Posted: 03.24.2020

By Inés Gutiérrez, Rodrigo Pérez Ortega Earlier this month, Mexico’s leading university, the National Autonomous University of Mexico (UNAM), announced that renowned neuroscientist Ranulfo Romo Trujillo would leave his position after being disciplined for an unspecified offense. According to a 4 March press release from UNAM, Romo Trujillo voluntarily asked to be separated from his job at UNAM’s University City campus in Mexico City. Sources close to the case say he had been temporarily suspended because a female worker made a formal complaint of sexual harassment against him following an incident in January. But current and former UNAM students and staff say that reports of inappropriate behavior by Romo Trujillo had circulated for years before his departure. Romo Trujillo, who works at UNAM’s Institute of Cellular Physiology (IFC), did not respond to repeated requests for comment. He is arguably the most famous neuroscientist in Mexico, studying perception, working memory, and decision-making. He has more than 150 publications, including in top journals such as Science and Nature; is on the editorial board of Neuron and other journals; and is one of 11 Mexican members of the U.S. National Academy of Sciences. IFC physiologist Marcia Hiriart Urdanivia acknowledged in an email to Science that, while director of IFC from 2009 to 2017, she received multiple accounts of sexual harassment or inappropriate conduct by Romo Trujillo. Hiriart Urdanivia says she warned Romo Trujillo that “his career was endangered by such actions.” But the women involved did not choose to file official complaints, she says. As a result, “I had no authority to do anything else.” © 2020 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 27129 - Posted: 03.21.2020

By Perri Klass, M.D. When you talk about sibling issues, everyone takes it personally. Whether it’s birth order and the supposed advantages of being the oldest (or youngest, or middle), or the question of having (or being) the favorite child, people tend to respond immediately with their own sometimes very individual and emotional stories. What I want to talk about today are sibling sex ratios — having a sibling of the other sex versus growing up in all-boy or all-girl sibling configurations. The most evocative phrase I’ve seen for this is “family constellations,” which I like because it suggests that there are lots of interesting — and even beautiful — arrangements, but that differences are real. But let’s take one step further back: Are there actually parents, or parent pairs, who are more likely to conceive boys or girls? Does the five-daughter family (from “Pride and Prejudice” or “Fiddler on the Roof”) or the seven-son setup (“Seven Brides for Seven Brothers”) just reflect five (or seven) random rolls of the dice, or is there actually something going on from an evolutionary point of view? The evolutionary theory, which has been advanced to explain sex ratio, goes back to Darwin, but was fully formulated in 1930 by a British scientist named Ronald Fisher, who made the argument that if individuals vary in the sex ratio among their offspring (that is, some are more likely to produce more males or more females), the reproductive advantage in a population will always lie with the rarer sex, and thus the sex ratio will equilibrate toward 1:1. After all, Fisher argued, half of the genetic material of the next generation must come by way of those who tend to produce males, and half from those who tend to produce females. But are there such tendencies? I’ve heard people say that having boys “runs in the family,” or that their cousins are almost all girls, that’s the “family pattern.” But a very large study of 4.7 million births in Sweden published in February in the journal Proceedings of the Royal Society argues that there is no evidence of a genetic tendency toward one sex or the other, or a family tendency. © 2020 The New York Times Company

Keyword: Development of the Brain; Sexual Behavior
Link ID: 27108 - Posted: 03.10.2020

Nicola Davis From humans to black-tailed prairie dogs, female mammals often outlive males – but for birds, the reverse is true. Now researchers say they have cracked the mystery, revealing that having two copies of the same sex chromosome is associated with having a longer lifespan, suggesting the second copy offers a protective effect. “These findings are a crucial step in uncovering the underlying mechanisms affecting longevity, which could point to pathways for extending life,” the authors write. “We can only hope that more answers are found in our lifetime.” The idea that a second copy of the same sex chromosome is protective has been around for a while, supported by the observation that in mammals – where females have two of the same sex chromosomes – males tend to have shorter lifespans. In birds, males live longer on average and have two Z chromosomes, while females have one Z and one W chromosome. Scientists say they have found the trend is widespread. Writing in the journal Biology Letters, the team report that they gathered data on sex chromosomes and lifespan across 229 animal species, from insects to fish and mammals. Hermaphroditic species and those whose sex is influenced by environmental conditions – such as green turtles – were not included. The results reveal that individuals with two of the same sex chromosomes live 17.6% longer, on average, than those with either two different sex chromosomes or just one sex chromosome. The team say the findings back a theory known as the “unguarded X hypothesis”. In human cells, sex chromosome combinations are generally either XY (male) or XX (female). In females only one X chromosome is activated at random in each cell. © 2020 Guardian News & Media Limited

Keyword: Sexual Behavior; Evolution
Link ID: 27090 - Posted: 03.04.2020

Dominique Sisley Nothing is quite as shattering as a broken heart. A bad breakup has been known to trigger a range of psychological and physical symptoms, from nausea and insomnia to clinical depression. In more extreme scenarios, broken heart syndrome – when a person’s heart stops pumping blood properly after an emotional shock – can lead to death. Fortunately, recent breakthroughs suggest we may soon be able to beat it. In March, a Spanish study found propofol, a sedative used for anaesthesia, may also be able to mute the painful memories that come with heartbreak. Participants were injected with the drug immediately after recalling a distressing story and, when asked to recount it again 24 hours later, they found the memory to be less vivid. Advertisement The principal goal of the research was to relieve the symptoms of post-traumatic stress disorder (PTSD), but it seems there may be scope for the drug to be used to suppress other upsetting memories. An unexpected loss such as heartbreak can also be traumatic, and some people report similar symptoms. Dr Bryan Strange, who led the study, says: “Combining anaesthesia with evoking an emotionally charged memory impairs its subsequent recall. We will need to derive a set of criteria that identify people for whom it works well, and where the benefit justifies the risk of anaesthesia. There may well be those for whom heartbreak is so distressing that the criteria is fulfilled.” In the past year, a wave of apps such as Mend, Rx Breakup and Break-Up Boss have been released, promising guidance, advice and distracting activities to help soothe the pain of heartbreak. It is a lofty promise, but one that appears to be rooted in logic: a study in 2017 found similar brain-training style exercises could help curb embarrassing or impulsive post-breakup behaviour and strengthen self-control. © 2020 Guardian News & Media Limited

Keyword: Depression; Sexual Behavior
Link ID: 27066 - Posted: 02.24.2020

By Randi Hutter Epstein It was a staple of medical thinking dating to the 1910s that stress was the body’s alarm system, switching on only when terrible things happened, often leaving a person with an either-or choice: fight or flight. The neuroscientist Bruce S. McEwen trailblazed a new way of thinking about stress. Beginning in the 1960s, he redefined it as the body’s way of constantly monitoring daily challenges and adapting to them. Dr. McEwen, who died on Jan. 2 at 81, described three forms of stress: good stress — a response to an immediate challenge with a burst of energy that focuses the mind; transient stress — a response to daily frustrations that resolve quickly; and chronic stress — a response to a toxic, unrelenting barrage of challenges that eventually breaks down the body. It was Dr. McEwen’s research into chronic stress that proved groundbreaking. He and his research team at Rockefeller University in Manhattan discovered in 1968 that stress hormones had a profound effect on the brain. In studies using animals (five rats in the initial one), Dr. McEwen and his colleagues demonstrated that toxic stress atrophied neurons near the hippocampus, the brain’s memory and learning center, while expanding neurons near the amygdala, an area known for vigilance toward threats. Describing the burden of continuing stress, he coined the term “allostatic load” (derived from allostasis, the process by which the body seeks to regain stability, or homeostasis, in response to stressors). Their discoveries, first published in the journal Nature in 1968, ignited a new field of research, one that would reveal how stress hormones and other mediators change the brain, alter behavior and impact health, in some cases accelerating disease. At the time, only a few scientists were asserting that the brain remains malleable throughout life, challenging the dogma that the brain stops changing after adolescence. Dr. McEwen’s studies documenting how hormones alter neurons lent credence to this emerging idea. © 2020 The New York Times Company

Keyword: Stress; Hormones & Behavior
Link ID: 27031 - Posted: 02.11.2020

By Shola Lawal These are tough times for fireflies. Like a lot of other insects, they face increasing threats from habitat loss, pesticides and pollution. But they also have a problem that’s unique to luminous bugs: It’s getting harder for them to reproduce because light pollution is outshining their mating signals. Fireflies, it turns out, use their special glowing powers in courtship: Males light up to signal availability and females respond with patterned flashes to show that they’re in the mood. But bright light from billboards, streetlights and houses is interfering and blocking potential firefly couples from pairing up. The problem can reach far from big cities: Bright light gets diffused in the atmosphere and can be reflected into the wilderness. In addition to messing with mating signals, it also disrupts the feeding patterns of the females of some species that glow to attract and eat males. The finding was part of a study published Monday in the journal BioScience. The study, by researchers at Tufts University and the International Union for Conservation of Nature, warned that fireflies could eventually face extinction globally because of multiple threats, including light pollution and habitat loss and habitat degradation from insecticides and chemical pollution. Many insects are affected by habitat loss, but fireflies have it particularly bad, said Sara M. Lewis, a biology professor at Tufts and the lead researcher on the study. “Some fireflies get hit especially hard when their habitat disappears because they need special conditions to complete their life cycle,” she said. Fireflies are a type of beetle. There are more than 2,000 species of them, found mainly in wetlands. But mangrove forests and marshes around the world are increasingly vanishing to make way for cash crops like palm oil, according to the new study. © 2020 The New York Times Company

Keyword: Sexual Behavior; Biological Rhythms
Link ID: 27018 - Posted: 02.04.2020

Rhitu Chatterjee One in seven women experiences depression during or after pregnancy. The good news is that perinatal depression is treatable. Here are five things to know about perinatal depression, its symptoms and treatment options. Loveis Wise for NPR Shortly after she gave birth to her son last May, Meghan Reddick, 36, began to struggle with depression. "The second I had a chance where I wasn't holding [my son], I would go to my room and cry," says Reddick, who lives with her son and husband. "And I probably couldn't count how many hours a day I cried." Reddick is among the many women who suffer from depression during pregnancy and after childbirth. "There's this kind of myth that women couldn't possibly be depressed during pregnancy, [that] this is such a happy time," says Jennifer Payne, a psychiatrist and the director of the Women's Mood Disorders Center at Johns Hopkins University. "The reality is that a lot of women struggle with anxiety and depression during pregnancy as well as during the postpartum period." An estimated one in seven women experiences depression during or after pregnancy. Among some groups, such as teenage moms and women with a history of trauma, the rate can be even higher. Left untreated, depression during this time can have serious consequences on the health of the mother, the baby and the entire family. © 2020 npr

Keyword: Depression; Sexual Behavior
Link ID: 27005 - Posted: 01.29.2020

By Matt Richtel The number of women drinking dangerous amounts of alcohol is rising sharply in the United States. That finding was among several troubling conclusions in an analysis of death certificates published Friday by the National Institute on Alcohol Abuse and Alcoholism. The analysis looked at deaths nationwide each year from 1999 through 2017 that were reported as being caused at least partly by alcohol, including acute overdose, its chronic use, or in combination with other drugs. The death rate tied to alcohol rose 51 percent overall in that time period, taking into account population growth. Most noteworthy to researchers was that the rate of deaths among women rose much more sharply, up 85 percent. In sheer numbers, 18,072 women died from alcohol in 2017, according to death certificates, compared with 7,662 in 1999. “More women are drinking and they are drinking more,” said Patricia Powell, deputy director of the alcohol institute, which is a division of the National Institutes of Health. Still, far more men than women die from alcohol-related illnesses, the study showed. In 2017, alcohol played a role in the deaths of 72,558 men, compared to 35,914 in 1999, a 35 percent increase when population growth is factored in. Like much research of its kind, the findings do not alone offer the reasons behind the increase in alcohol deaths. In fact, the data is confounding in some respects, notably because teenage drinking overall has been dropping for years, a shift that researchers have heralded as a sign that alcohol has been successfully demonized as a serious health risk. Experts said that the new findings could partly reflect the fact that baby boomers are aging and the health effects of chronic alcohol use have become more apparent. The increase in deaths might also reflect the increase in opioid-related deaths, which in many cases can involve alcohol as well, and that would be reflected on death certificates. © 2020 The New York Times Company

Keyword: Drug Abuse; Sexual Behavior
Link ID: 26955 - Posted: 01.13.2020

Emily Makowski Bruce McEwen, a neuroendocrinologist at Rockefeller University, died January 2 after a brief illness. He was 81 years old. McEwen is best known for his research on how stress hormones can reconfigure neural connections in the brain, according to a university statement. In 1968, McEwen and his colleagues discovered that the rat hippocampus is affected by the hormone cortisol, sparking further research into how hormones can enter the brain and affect mental functioning and mood. At the time, most scientists believed that the brain was not malleable after becoming fully developed, a line of thinking that McEwen’s research findings contradicted. In 1993, he coined the term allostatic load, which describes the physiological effects of chronic stress. With his wife, Karen Bulloch, a Rockefeller professor, he studied how immune cells in the brain increase during a person’s lifespan and can contribute to neurodegenerative disease. He also researched how sex hormones affect the central nervous system. Over the course of his career, which spanned six decades, McEwen received many accolades including the Pasarow Foundation award in neuropsychiatry, the Fondation Ipsen Neuronal Plasticity and Endocrine Regulation prizes, the Scolnick Prize in Neuroscience, and the William James Lifetime Achievement Award for Basic Research. He was a member of the National Academy of Sciences, the National Academy of Medicine, and the American Society of Arts and Sciences. “Bruce was a giant in the field of neuroendocrinology,” McEwen’s colleague Leslie Vosshall, a neuroscientist at Rockefeller, says in the statement. “He was a world leader in studying the impact of stress hormones on the brain, and led by example to show that great scientists can also be humble, gentle, and generous human beings.” © 1986–2020 The Scientist

Keyword: Stress; Hormones & Behavior
Link ID: 26942 - Posted: 01.09.2020

Nell Greenfieldboyce Shepherds in Christmas Nativity scenes that were painted, carved or sculpted hundreds of years ago sometimes have throats with large, abnormal growths. These are realistic depictions of goiter, an enlargement of the thyroid gland caused by iodine deficiency. The condition was common in those days in northern Italy, where the soil and water are depleted of iodine. "Goiter is more often seen in poor people," says retired surgeon Renzo Dionigi of the University of Insubria in Varese, Italy, who notes that the working classes in this region would historically not have a varied diet that might supply this vital nutrient. "That's why, probably, the poor shepherds are depicted with goiters," he says. He and his son, an endocrine surgeon named Gianlorenzo Dionigi, have for years enjoyed studying art and looking for signs of medical conditions. In the Sacri Monti ("Sacred Mountains") of Piedmont and Lombardy, they have visited chapels and churches created in the 16th and 17th centuries. "In all the Sacri Monti that I and my son visited, we have been able to observe representations of goiters very, very often," says the elder Dionigi. In one Nativity tableau from 1694, for example, a young horn player with a large goiter plays for the Holy Family. And in one fresco over the main door of the Aosta Cathedral, a shepherd with goiter plays his bagpipe for the newborn Jesus. © 2019 npr

Keyword: Hormones & Behavior
Link ID: 26913 - Posted: 12.26.2019

Nicola Slawson When Lynn Enright had a hysteroscopy to examine the inside of the womb, her searing pain was dismissed by medical professionals. She only understood why when she started working on her book on female anatomy, Vagina: A Re-education. She was looking for research on pain and women’s health, only to be shocked by how little data she found. It wasn’t just the topic of pain that was poorly researched. The lack of evidence was a problem she encountered time and time again, which is no surprise when you look at the research gap: less than 2.5% of publicly funded research is dedicated solely to reproductive health, despite the fact that one in three women in the UK will suffer from a reproductive or gynaecological health problem. There is five times more research into erectile dysfunction, which affects 19% of men, than into premenstrual syndrome, which affects 90% of women. “Women have been woefully neglected in studies on pain. Most of our understanding of ailments comes from the perspective of men; it is overwhelmingly based on studies of men, carried out by men,” Enright says. Her book is one of several in the past year about the female body and the impact a lack of knowledge can have on diagnosis and treatment. They include Emma Barnett’s Period, Eleanor Morgan’s Hormonal, and Gabrielle Jackson’s Pain and Prejudice, which draws on her experience of being diagnosed with endometriosis, a chronically underfunded condition. Given that in the US, which produces a lot of medical research, research trials weren’t required by the National Institutes of Health to include women until 1993, the lack of knowledge is perhaps no surprise. Traditionally this was justified by the idea that women’s bodies were seen to be too complex due to fluctuating hormones, so clinical trials often excluded them. © 2019 Guardian News & Media Limited

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 26898 - Posted: 12.18.2019

By Rachel E. Gross In the 1960s, manufacturers of the new birth-control pill imagined their ideal user as feminine, maternal and forgetful. She wanted discretion. She was married. And she wanted visible proof that her monthly cycle was normal and that she wasn’t pregnant. In 2019, the user of the pill is perceived as an altogether different person. She’s unwed, probably would prefer to skip her period and is more forthright about when it’s that time of the month. As such, many birth-control brands now come in brightly colored rectangular packs that make no effort to be concealed. But one part of the equation remains: the week of placebo pills, in which hormones are abruptly withdrawn and a woman experiences what looks and feels a lot like her regular period — blood, cramps and all — but isn’t. Physicians have widely described this pseudoperiod as medically unnecessary. So why do millions still endure it? That’s largely the legacy of two men: John Rock and David Wagner. First there’s Rock, a Harvard fertility expert and a developer of the pill. There’s a longstanding myth that Rock, a Catholic, designed the pill in the 1950s with the church in mind and included a week of hormonal withdrawal — and therefore bleeding — to make his invention seem more natural. In fact, the thought never crossed his mind, the Rutgers University historian Margaret Marsh says. Instead, it was Gregory (Goody) Pincus, the other developer of the pill, who suggested that the pill be given as a 20-days-on, 5-days-off regimen. Pincus wanted to provide women in his trials with reassurance that they weren’t pregnant, and to know himself that the pill was working as a contraceptive. Rock agreed. After the F.D.A. approved the pill in 1960, however, those few days of light bleeding took on a new significance. Anticipating the church’s opposition, Rock became not just a researcher but also an advocate. In his 1963 book “The Time Has Come: A Catholic Doctor’s Proposals to End the Battle Over Birth Control,” he argued that the pill was merely a scientific extension of the church-sanctioned “rhythm method.” It “completely mimics” the body’s own hormones, he wrote, to extend the “safe period” in which a woman could have intercourse and not become pregnant. © 2019 The New York Times Company

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 26892 - Posted: 12.12.2019

By Eva Frederick Many human grandmothers love to spoil their grandchildren with attention and treats, and for good reason: Studies have shown that having a living grandmother increases a child’s chance of survival. Now, new research shows the same may be true for killer whales. By providing young animals with some freshly caught salmon now and then—or perhaps with knowledge on where to find it—grannies increase their grand-offspring’s chance of survival. The new study is the first direct evidence in nonhuman animals of the “grandmother hypothesis.” The idea posits that females of some species live long after they stop reproducing to provide extra care for their grandchildren. “It’s very cool that these long-lived cetaceans have what looks like a postfertile life stage,” says Kristen Hawkes, an anthropologist at the University of Utah in Salt Lake City who has dedicated much of her career to studying the grandmother effect; she was not involved in the new study. Women usually go through menopause between ages 45 and 55, even though they may live to age 80, 90, or older. Studies in modern-day hunter-gatherer communities as well as in populations in Finland and Canada show that older women can help increase the number of children their daughters have, and boost the survival rates of their grandchildren. Dan Franks, a computer scientist and biologist at the University of York in the United Kingdom, wanted to know whether this grandmother effect occurs in other species as well. © 2019 American Association for the Advancement of Science

Keyword: Sexual Behavior; Evolution
Link ID: 26887 - Posted: 12.10.2019

Andrew Anthony Katrina Karkazis, a senior research fellow at Yale University, is a cultural anthropologist working at the intersection of science, technology, gender studies and bioethics. With Rebecca Jordan-Young, a sociomedical scientist, she has written Testosterone: An Unauthorised Biography. It is a critique of both popular and scientific understandings of the hormone, and how they have been used to explain, or even defend, inequalities of power. You suggest that testosterone is understood as an exclusively male hormone, even though it’s also found in women. But surely no scientist believes this. No, what we’re saying is that the hormone has a century-long biography and identity that continues to be that of a male sex hormone. That language is used by authoritative sources in the US like the National Library of Medicine, but also in many media articles. It’s an argument that has to do with how the hormone is understood, which then shapes the kinds of research questions that get asked, what kinds of research get done or not done. There’s actually almost no research on the relationship between testosterone and aggression in women. That is a consequence of the framing of the hormone as having to do with men, masculinity, behaviours understood and framed as masculine. It’s the idea that because men generally have more testosterone, somehow that makes it more relevant in men. But the truth is we know very little about it. You write that testosterone’s authorised biography is about libido, aggression and masculinity. Does this mean that testosterone is not about these things? I think that it’s still very widely understood as the driver of all things masculine. When people think about testosterone, aggression is one of the first things that comes to mind. But when you look at the evidence, there’s not good evidence at all. In fact, it’s very weak regarding the relationship between endogenous testosterone [ie testosterone that originates within an organism] and aggression. So it’s an artefact of the ideology of testosterone that we continue to believe that it drives aggression, because aggression has been framed as a masculine behaviour and testosterone has been framed as a masculine hormone. © 2019 Guardian News & Media Limited

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 26883 - Posted: 12.09.2019

By Laura Sanders “Does the pill cause depression?” the news headline asked. Prompted by a recent study that described a link between taking birth control pills as a teenager and depression in adulthood, the news got some doctors hopping mad. Early research hints that there are reasons to look more closely at hormonal birth control’s side effects. But so far, the link is less than certain. “This is a premature connection,” says pediatrician Cora Breuner of Seattle Children’s Hospital. Putting too much stock in preliminary evidence may lead to fewer teenagers getting birth control and, in turn, more unwanted pregnancies among teens — a situation that can upend young lives, Breuner says. Headlines that frighten teens, their families and doctors are “yet another barrier in place for accessing a completely effective way to prevent unplanned pregnancies.” Ob-gyn and contraception researcher Katharine O’Connell White agrees. “Birth control gets all of the worry and concern,” says White, of Boston University School of Medicine. “But we know that other things are much more dangerous.” Teen pregnancy, for instance. Access to effective birth control is vital for sexually active teenagers, the doctors say. “I don’t think the evidence is there right now to say that this is a threat,” adds epidemiologist and public health researcher Sarah McKetta of Columbia University, who has studied birth control use in teens. Still, she sees value in more research on the issue. “Women deserve good medication … that’s not giving them problems.” If there are risks that come with the pill, then scientists ought to get a handle on them. © Society for Science & the Public 2000–2019

Keyword: Depression; Hormones & Behavior
Link ID: 26864 - Posted: 12.02.2019

By James Gorman TEMPE, Ariz. — Xephos is not the author of “Dog Is Love: Why and How Your Dog Loves You,” one of the latest books to plumb the nature of dogs, but she helped inspire it. And as I scratched behind her ears, it was easy to see why. First, she fixed on me with imploring doggy eyes, asking for my attention. Then, every time I stopped scratching she nudged her nose under my hand and flipped it up. I speak a little dog, but the message would have been clear even if I didn’t: Don’t stop. We were in the home office of Clive Wynne, a psychologist at Arizona State University who specializes in dog behavior. He belongs to Xephos, a mixed breed that the Wynne family found in a shelter in 2012. Dr. Wynne’s book is an extended argument about what makes dogs special — not how smart they are, but how friendly they are. Xephos’ shameless and undiscriminating affection affected both his heart and his thinking. As Xephos nose-nudged me again, Dr. Wynne was describing genetic changes that occurred at some point in dog evolution that he says explain why dogs are so sociable with members of other species. “Hey,” Dr. Wynne said to her as she tilted her head to get the maximum payoff from my efforts, “how long have you had these genes?” No one disputes the sociability of dogs. But Dr. Wynne doesn’t agree with the scientific point of view that dogs have a unique ability to understand and communicate with humans. He thinks they have a unique capacity for interspecies love, a word that he has decided to use, throwing aside decades of immersion in scientific jargon. © 2019 The New York Times Company

Keyword: Sexual Behavior; Language
Link ID: 26848 - Posted: 11.23.2019

Ruth Williams After copulation, Drosophila melanogaster females are able to create long-term memories of unpleasant events—electric shocks—that virgin females cannot, according to a study published today in Science Advances (November 20). The authors suspect the memory boost may improve the chance of survival of the female during the subsequent egg-laying period as well as guide her choice of laying sites. Whatever the reason, the enhanced memory joins a list of physiological and behavioral effects on female flies that result from sex. “It’s quite impressive and convincing [data],” says entomologist Elwyn Isaac of the University of Leeds who was not involved in the research. “They propose that the sex peptide gets into the [female’s] circulation and somehow gets across the blood brain barrier [to activate memory].” It’s “very interesting,” Isaac continues, because until now, sex peptide—a protein produced in the male reproductive system and found in ejaculate—was thought to act on sensory neurons in the female’s uterus. These neurons produce a receptor protein to which sex peptide binds and are thought to be necessary for the peptide’s many effects on females, which include ramping up ovulation, increasing egg-laying behavior, changing food preference to a high-protein diet, and causing the female to reject other males. But, the authors of the new study, “show definitely that those neurons are not required for this [long-term memory] effect,” Isaac says. Indeed, deletion of the receptor in these neurons made no difference to the flies’ long-term memory formation after sex. © 1986–2019 The Scientist

Keyword: Learning & Memory; Sexual Behavior
Link ID: 26843 - Posted: 11.22.2019

Jef Akst From a small inflatable boat in the Rangiroa atoll in French Polynesia, Pamela Carzon got her first glimpse of the “strange” trio of marine mammals she’d been told about: a bottlenose dolphin mother (Tursiops truncatus), her seven-month-old calf, and another young cetacean that was slightly smaller and looked to be not a bottlenose dolphin at all, but a melon-headed whale (Peponocephala electra). It was April 2015, and Carzon and a colleague at the Marine Mammal Study Group of French Polynesia, a nongovernmental organization dedicated to whale and dolphin conservation, were out for the NGO’s annual photo-ID survey, very much hoping to find animals that a former collaborator had seen while diving in the region the previous November. “[T]he sea was very calm, and there were many dolphins around,” Carzon, also a PhD student at the Center for Island Research and Environmental Observatory (CRIOBE) in French Polynesia and the École Pratique des Hautes Études in Paris, recalls in an email to The Scientist. “It took us maybe two minutes to spot them: the dark calf was easy to spot among the bottlenose dolphins.” The mother, dubbed ID#TP25 by the researchers, was known to tolerate divers and boats, and that April day she approached the inflatable with both calves. Carzon grabbed her underwater camera and slipped into the water. “I was able to get good underwater footage and to sex both calves,” she says. ID#TP25’s natural calf was a female; the second calf was male. “I also noticed that both were ‘gently’ pushing each other [in order] to remain under the adult female’s abdomen” in so-called infant position. Continued observation over the following months revealed that the dolphin mom was nursing the foreign calf, whose species ID remains to be confirmed with genetic testing, and otherwise treated him as one of her own. © 1986–2019 The Scientist.

Keyword: Sexual Behavior
Link ID: 26836 - Posted: 11.20.2019