By Aayushi Pratap In Rector, Pa., researchers have spotted one strange bird. This rose-breasted grosbeak has a pink breast spot and a pink “wing pit” and black feathers on its right wing — telltale shades of males. But on its left side, the songbird displays yellow and brown plumage, hues typical of females. Annie Lindsay had been out capturing and banding birds with identification tags with her colleagues at Powdermill Nature Reserve in Rector on September 24 when a teammate hailed her on her walkie-talkie to alert her of the bird’s discovery. Lindsay, who is banding program manager at Powdermill, immediately knew what she was looking at: a half-male, half-female creature known as a gynandromorph. “It was spectacular. This bird is in its nonbreeding [plumage], so in the spring when it’s in its breeding plumage, it’s going to be even more starkly male, female,” Lindsay says. The bird’s colors will become even more vibrant, and “the line between the male and female side will be even more obvious.” Gynandromorphs are found in many species of birds, insects and crustaceans such as crabs and lobsters. This bird is likely the result of an unusual event when two sperm fertilize an egg that has two nuclei instead of one. The egg can then develop male sex chromosomes on one side and female sex chromosomes on the other, ultimately leading to a bird with a testis and other male characteristics on one half of its body and an ovary and other female qualities on the other half. © Society for Science & the Public 2000–2020

Keyword: Sexual Behavior
Link ID: 27506 - Posted: 10.07.2020

By Cara Giaimo Last year, Katie Goldin was walking in her Los Angeles neighborhood when she saw, in the middle of the sidewalk, two lizards interlocked. The male, flecked like a pebble and about a foot long, had his jaws fully around the slightly smaller female’s head. “He was tenderly clasping her neck in his mouth,” said Ms. Goldin, host of a podcast called “Creature Feature.” “She seemed like she was in a trance.” Even in a world absolutely full of bizarre reproductive strategies, southern alligator lizards are up there. The pair Ms. Goldin spotted were engaged in what’s known as “mate-holding,” a part of the copulatory process in which a male grips a female’s head in his mouth for hours or even days at a time. It’s not clear why the lizards do this. But recently, two research projects have looked into the animals’ ecology and anatomy to better understand where, when and how this strange behavior happens. By approaching the same subject from these very different vantage points, scientists can inform each other’s research, and get a clearer picture of what’s really going on. Spying on lizard sex, for science After Ms. Goldin saw the happy couple, she sent pictures to the Natural History Museum of Los Angeles County. Since 2015, the museum has put out a yearly call for photos and videos of alligator lizards getting it on, which it collects through emails, social media and the platform iNaturalist. The species is the most widespread reptile in Los Angeles. But because the city is a “jigsaw puzzle of private property,” it’s difficult to do traditional wildlife surveys, said Greg Pauly, the museum’s herpetology curator. There are only a handful of published accounts of the lizard’s mating behavior in the scientific literature. © 2020 The New York Times Company

Keyword: Sexual Behavior; Aggression
Link ID: 27500 - Posted: 09.30.2020

By Lisa Grossman Clues from a chemical — Science News, October 3, 1970 An experimental drug’s effects on the sexual behavior of certain animals is arousing interest among investigators.… The drug, para-chlorophenylalanine … reduces the level of a naturally occurring neurochemical, serotonin, in the brain of rats, mice and dogs.… Little is known about how serotonin acts in the brain, and investigators quickly recognized that PCPA could be used to study this brain chemical. Update PCPA helped e­stablish serotonin’s role in regulating sexual desire, as well as sleep, appetite and mood. The chemical messenger has become key to one common class of antidepressant drugs called selective serotonin r­euptake inhibitors. Identified in 1974, SSRIs work by increasing the brain’s serotonin levels. But such drugs can hinder sexual desire. One SSRI that failed to relieve depression in humans found a second life as a treatment for sexual dysfunction. Approved by the U.S. Food and Drug Administration in 2015, this “little pink pill,” sold as Addyi, may boost sex drive in women by lowering serotonin in the brain’s reward centers. H.A. Croft. Understanding the role of serotonin in female hypoactive sexual desire disorder and treatment options. Journal of Sexual Medicine. Vol. 14, December 2017, p. 1575. Doi: 10.1016/j.jsxm.2017.10.068. © Society for Science & the Public 2000–2020.

Keyword: Depression; Sexual Behavior
Link ID: 27497 - Posted: 09.30.2020

The benefits of companionship for humans are well known, and they're not just confined to our mental health. Humans with strong social bonds with others live longer, healthier lives. Now a study looking at wild baboons in Africa has shown this is true for them as well. In particular, male baboons with non-sexual friendships with females live far longer than animals who lack these social bonds. Researchers have known for years that companionship is beneficial for the health and longevity of female baboons. But because of their social structure, male baboons are much harder to study over a long term than females. Female baboons stay with their birth troop for their entire lives, and so are easy to track and observe. Males, on the other hand, switch troops after they mature, and sometimes in adulthood as well, and so tracking them for their lifetime — which averages something like a decade and a half — can be a challenge. But a team led by Susan Alberts, a professor of biology and chair of the evolutionary anthropology department at Duke University, was able to master this problem. Friends with benefits Platonic friendship among baboons of the opposite sex is, it turns out, common. According to Alberts, male baboons will frequently form non-sexual friendship bonds with females and will protect them and their offspring from aggression within the troop and from predators. The benefits of this for the females are clear. What was less clear was the benefits of this kind of companionship for the males. The new study from Alberts and her team drew on data collected over many years from over 500 baboons at Amboseli National Park in Kenya to answer that question.. ©2020 CBC/Radio-Canada.

Keyword: Stress; Sexual Behavior
Link ID: 27492 - Posted: 09.28.2020

By Ann Gibbons Neanderthals have long been seen as uber-masculine hunks, at least compared with their lightweight human cousins, with whom they competed for food, territory, and mates. But a new study finds Homo sapiens men essentially emasculated their brawny brethren when they mated with Neanderthal women more than 100,000 years ago. Those unions caused the modern Y chromosomes to sweep through future generations of Neanderthal boys, eventually replacing the Neanderthal Y. The new finding may solve the decade-old mystery of why researchers have been unable to find a Neanderthal Y chromosome. Part of the problem was the dearth of DNA from men: Of the dozen Neanderthals whose DNA has been sequenced so far, most is from women, as the DNA in male Neanderthal fossils happened to be poorly preserved or contaminated with bacteria. “We began to wonder if there were any male Neanderthals,” jokes Janet Kelso, a computational biologist at the Max Planck Institute for Evolutionary Anthropology and senior author of the new study. But in a technical breakthrough, Max Planck graduate student Martin Petr designed a set of probes that used the DNA sequence from small chunks of modern men’s Y chromosomes to “fish out” and bind with DNA from archaic men’s Y chromosomes. The new method works because the Neanderthal and modern human chromosomes are mostly similar; the DNA probes also reel in the few basepairs that differ. The researchers probed the fragmentary Y chromosomes of three Neanderthal men from Belgium, Spain, and Russia who lived about 38,000 to 53,000 years ago, and two male Denisovans, close cousins of Neanderthals who lived in Siberia’s Denisova Cave about 46,000 to 130,000 ago. When the researchers sequenced the DNA, they got a surprise: The Neanderthal Y “looked more like modern humans’ than Denisovans’,” Kelso says. © 2020 American Association for the Advancement of Science.

Keyword: Sexual Behavior
Link ID: 27484 - Posted: 09.25.2020

Zeeya Merali Discovering the “on-and-off switch” for good parenting in male and female mouse brains has earned Catherine Dulac, a molecular biologist at Harvard University in Cambridge, Massachusetts, one of this year’s US$3-million Breakthrough prizes — the most lucrative awards in science and mathematics. Three other major prizes in biology, plus two in physics and one in mathematics, were also announced on 10 September, together with a number of smaller prizes. “Catherine Dulac has done amazing work that has really transformed the field,” says biologist Lauren O’Connell at Stanford University, California. Dulac’s team provided the first evidence that male and female mouse brains have the same neural circuitry associated with parenting, which is just triggered differently in each sex1. “It went against the dogma that for decades said that male and female brains are organized differently,” says O’Connell. Dulac says she was stunned to learn that she had won the award. “My brain froze, then I began to tear up,” she says, adding that it had been a long road to acceptance, because others had initially been sceptical of her work. In the 1990s, Dulac isolated the pheromone receptors in mice that govern sex-specific social behaviours. Virgin male mice usually attack other males and kill pups. But Dulac found that if their pheromone receptors were blocked, they would attempt to mate with both males and females, and virgin males would even care for pups. Pheromone-blind females, by contrast, would attempt to mount males. © 2020 Springer Nature Limited

Keyword: Sexual Behavior
Link ID: 27467 - Posted: 09.12.2020

By Katharine Q. Seelye Shere Hite, who startled the world in the 1970s with her groundbreaking reports on female sexuality and her conclusion that women did not need conventional sexual intercourse — or men, for that matter — to achieve sexual satisfaction, died on Wednesday at her home in London. She was 77. Her husband, Paul Sullivan, confirmed the death to The Guardian. The newspaper quoted a friend of Ms. Hite’s as saying that she had been treated for Alzheimer’s and Parkinson’s diseases. Her most famous work, “The Hite Report: A Nationwide Study of Female Sexuality” (1976), challenged societal and Freudian assumptions about how women achieved orgasm: It was not necessarily through intercourse, Ms. Hite wrote; women, she found, were quite capable of finding sexual pleasure on their own. However obvious her conclusions might seem today, they were seismic at the time and “sparked a revolution in the bedroom,” as Ms. magazine reported. For all the women who had faked orgasm during intercourse, the Hite Report helped awaken their sexual power and was seen as advancing the liberation of women that was rapidly underway. The book became an instant best seller and has been translated into a dozen languages. More than 48 million copies have been sold worldwide. What set the Hite Report apart from other studies were the questionnaires at the heart of it. More than 3,000 women were given anonymity in answering the queries, allowing them to write candidly and open-endedly — not in response to multiple-choice questions — about their experiences. “Researchers should stop telling women what they should feel sexually and start asking them what they do feel sexually,” Ms. Hite wrote. She described her questionnaires as a “giant rap session on paper.” In revelatory first-person testimonials, more than 70 percent of the respondents shattered the notion that women received sufficient stimulation during basic intercourse to reach climax. Rather, they said, they needed stimulation of the clitoris but often felt guilty and inadequate about it and were too embarrassed to tell their sexual partners. © 2020 The New York Times Company

Keyword: Sexual Behavior
Link ID: 27464 - Posted: 09.12.2020

Sean Ingle The double Olympic 800m champion Caster Semenya appears to have lost her long-running legal battle against regulations requiring women with high testosterone to take medication to compete internationally between 400m and a mile. A Swiss federal tribunal said on Tuesday that it supported a decision by the court of arbitration for sport last year that track and field’s policy for athletes with differences in sex development (DSD) was “necessary, reasonable and proportionate” to ensure fair competition in women’s sport. Charley Hull withdraws from ANA Inspiration after positive Covid-19 test Read more “Based on these findings, the Cas decision cannot be challenged,” the tribunal said. “Fairness in sport is a legitimate concern and forms a central principle of sporting competition. It is one of the pillars on which competition is based.” It now looks impossible for Semenya, the London 2012 and Rio 2016 gold medallist, to defend her title in Tokyo. She responded to the news by accusing World Athletics of being on the “wrong side of history”. “I am very disappointed by this ruling, but refuse to let World Athletics drug me or stop me from being who I am,” she said. “Excluding female athletes or endangering our health solely because of our natural abilities puts World Athletics on the wrong side of history. I will continue to fight for the human rights of female athletes, both on the track and off the track, until we can all run free the way we were born.” The South African was almost unstoppable until World Athletics implemented a new policy for DSD athletes, including Semenya, that compelled them to reduce their testosterone levels to less than 5 nmol/L if they wanted to compete in elite events between 400m and a mile. © 2020 Guardian News & Media Limited

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 27462 - Posted: 09.09.2020

A line of elephants trundles across a dusty landscape in northern Botswana, ears flapping and trunks occasionally brushing the ground. As they pass a motion-activated camera hidden in low shrubbery, photos record the presence of each elephant. What's special about this group? It's only males. Female elephants are known to form tight family groups led by experienced matriarchs. Males were long assumed to be loners, because they leave their mother's herd when they reach 10 to 20 years of age. A new study shows that teenage males aren't anti-social after all. Younger male elephants were seen tagging along behind older males as they travel from place to place. It's more evidence in an emerging body of research that shows older males — like their female counterparts — play an important role in elephants' complex society. For the study published Thursday in the journal Scientific Reports, researchers analyzed photos of 1,264 sightings of male African savannah elephants travelling toward the Boteti River in 2017 and 2018. They found that younger males seldom travelled alone and older males most often led groups of mixed ages. "Mature male elephants often take a position at the front of the line when they are leading the group" to streams or seasonal grazing grounds, said Diana Reiss, director of the Animal Behavior and Conservation Program at Hunter College, who was not involved in the new study. "In human societies, grandparents are valued because they make really important contributions — helping with childcare and passing down knowledge gained over decades," she said. "We're now learning this pattern is also true for some other long-lived mammals, including dolphins, whales and elephants." Photos of 1,264 sightings of male African savannah elephants travelling toward the Boteti River in 2017 and 2018 showed that younger males seldom travelled alone and older males most often led groups of mixed ages. (Connie Allen) ©2020 CBC/Radio-Canada

Keyword: Sexual Behavior; Aggression
Link ID: 27452 - Posted: 09.05.2020

For Armin Raznahan, publishing research on sex differences is a fraught proposition. Now chief of the section on developmental neurogenomics at the National Institutes of Health, Raznahan learned early that searching for dissimilarities between men’s and women’s brains can have unintended effects. “I got my fingers burned when I first started,” Raznahan says. As a PhD student, he published a study that examined structural differences between men’s and women’s brains and how they changed with age. “We observed a particular pattern, and we were very cautious about just describing it, as one should be, not jumping to functional interpretations,” he says. Despite his efforts, The Wall Street Journal soon published an article that cited his study in a defense of single-sex schooling, under the assumption that boys and girls must learn in distinct ways because their brain anatomy is slightly different. “That really threw me,” he says. “The experience has stayed with me.” Nevertheless, Raznahan has continued to study sex differences, in the hope that they could help us better understand neurodevelopmental disorders. He focuses on people with sex chromosome aneuploidy, or any variation other than XX (typically female) and XY (typically male). People with genetic variations (such as XXY) have an inflated risk of autism spectrum disorder, ADHD, and anxiety, among other ailments. Raznahan’s hope is that uncovering if and how men’s and women’s brains differ—for example, in the sizes of regions or the strengths of the connections among them—could help us figure out why people with aneuploidy are more likely to experience neurodevelopmental and psychiatric concerns. Solving this puzzle could be a step toward unlocking the perplexing mystery of psychiatric illness. © 2020 Condé Nast

Keyword: Sexual Behavior; Brain imaging
Link ID: 27451 - Posted: 09.05.2020

By Carolyn Wilke Female hyenas may be out for cubs’ blood — even within their own clans. New research suggests that infanticide may be part of a strategy females use to maintain their social standing. “It’s not that these events are weird one-off things … this is actually a pretty significant source of mortality,” says Eli Strauss, a behavioral ecologist at the University of Nebraska–Lincoln. Strauss and his colleagues scoured three decades of data on spotted hyena populations in Kenya to study deaths of cubs less than a year old (SN: 4/23/02). Of 99 observed deaths, 21 could be attributed to infanticide, always by female killers. Starvation and lions also took many young cubs’ lives. The infanticide observations made the team wonder why hyenas kill within their own group. It “seems sort of counterintuitive if animals benefit from living socially,” Strauss says. Though hyenas spend much of their time alone, group living allows them to defend their turf against rival hyena clans and to gang up against threatening lions, he says. Hyena mothers give birth in an isolated den. But typically within a few weeks, they move their cubs to a communal den. Such dens shelter little ones from large predators that can’t enter the sanctuary’s small access holes, says Ally Brown, an environmental biology student at Michigan State University in East Lansing. But the communal den presents other risks — all the cases of infanticide occurred in its vicinity, documented by researchers who either found the dead cubs or observed the clans from cars that serve as mobile blinds (SN: 4/23/02). © Society for Science & the Public 2000–2020.

Keyword: Aggression; Sexual Behavior
Link ID: 27436 - Posted: 08.26.2020

By Apoorva Mandavilli The coronavirus may infect anyone, young or old, but older men are up to twice as likely to become severely sick and to die as women of the same age. Why? The first study to look at immune response by sex has turned up a clue: Men produce a weaker immune response to the virus than do women, the researchers concluded. The findings, published on Wednesday in Nature, suggest that men, particularly those over age 60, may need to depend more on vaccines to protect against the infection. “Natural infection is clearly failing” to spark adequate immune responses in men, said Akiko Iwasaki, an immunologist at Yale University who led the work. The results are consistent with what’s known about sex differences following various challenges to the immune system. Women mount faster and stronger immune responses, perhaps because their bodies are rigged to fight pathogens that threaten unborn or newborn children. But over time, an immune system in a constant state of high alert can be harmful. Most autoimmune diseases — characterized by an overly strong immune response — are much more prevalent in women than in men, for example. “We are looking at two sides of the same coin,” said Dr. Marcus Altfeld, an immunologist at the Heinrich Pette Institute and at the University Medical Center Hamburg-Eppendorf in Germany. The findings underscore the need for companies pursing coronavirus vaccines to parse their data by sex and may influence decisions about dosing, Dr. Altfeld and other experts said. © 2020 The New York Times Company

Keyword: Sexual Behavior; Neuroimmunology
Link ID: 27435 - Posted: 08.26.2020

By Gillian R. Brassil and Jeré Longman A restrictive Idaho law — temporarily blocked by a federal judge Monday night — has amplified a charged debate about who should be allowed to compete in women’s sports, as transgender athletes have become increasingly accepted on the playing field while still facing strong resistance from some competitors and lawmakers. While scientific and societal views of sex and gender identity have changed significantly in recent decades, a vexing question persists regarding athletes who transition from male to female: how to balance inclusivity, competitive fairness and safety. There are no uniform guidelines — in fact the existing rules that govern sports often conflict — to determine the eligibility of transgender women and girls (policy battles have so far primarily centered on regulating women’s sports). And there is scant research on elite transgender athletes to guide sports officials as they attempt to provide equitable access to sports while reconciling any residual physiological advantages that may carry on from puberty. Dr. Eric Vilain, a geneticist specializing in sexual development who has advised the N.C.A.A. and the International Olympic Committee on policies for transgender athletes, said that sports leaders were confronted with “two almost irreconcilable positions” in setting eligibility standards — one relying on an athlete’s declared gender and the other on biological litmus tests. Politics, too, have entered the debate in a divided United States. While transgender people have broadly been more accepted across the country, the Trump administration and some states have sought to roll back protections for transgender people in health care, the military and other areas of civil rights, fueling a rise in hate crimes, according to the Human Rights Campaign. In March, Idaho became the first state to bar transgender girls and women from participating in women’s sports. © 2020 The New York Times Company

Keyword: Sexual Behavior
Link ID: 27426 - Posted: 08.20.2020

By Hannah Thomasy Some 2 percent of men in the U.S. identify as bisexual. But, for decades, some sexuality researchers have questioned whether true bisexual orientation exists in men. In 2005, J. Michael Bailey, a sexuality researcher at Northwestern University, and two colleagues showed men who identify as bisexual brief pornographic clips featuring men or women, while measuring their subjects’ self-reported arousal and change in penis circumference. The results, when compared to men who identified as straight or gay, led them to conclude that the men identifying as bisexual did not actually have “strong genital arousal to both male and female sexual stimuli.” This was in contrast to work on sexual arousal in women, which showed that they — whether identifying as straight or gay — were physically aroused by both male and female stimuli. A New York Times headline covering Bailey’s 2005 study on men declared: “Straight, Gay, or Lying? Bisexuality Revisited.” But the paper also spurred more research into the subject — some of which has now led Bailey to revise his conclusions. In a paper published last month in the Proceedings of the National Academy of Sciences (PNAS), Bailey and 12 colleagues reanalyzed data from eight previously published studies of bisexual-identified men, including the 2005 paper. The new review finds that men who reported attraction to both men and women do in fact show genital arousal towards both male and female stimuli. The data, the authors conclude, offers “robust evidence for bisexual orientation among men.” The PNAS study has drawn positive coverage and received praise from some activists, who see it as valuable confirmation for an often-marginalized sexual identity. But it has also received backlash from other scientists and many bisexual people, some of whom argue that in attempting to prove, based on genital arousal, that bisexuality exists, researchers are discounting bisexual people’s lived experiences. It has also reignited a broader debate over the ethics of human sexuality research — and about what role, if any, scientists should play in validating the experiences of queer people.

Keyword: Sexual Behavior
Link ID: 27422 - Posted: 08.18.2020

By Joshua Sokol A beast calls in the distance. Hearing a low rumble, you might imagine the source will be an unholy cross between a wild boar and a chain saw. The message is unmistakable: I’m here, I’m huge and you can either come mate with me or stay out of my way. Surprise! It’s just a cuddly little koala. Like online dating, the soundscape of the animal world is rife with exaggerations about size, which animals use to scare off rivals and attract mates. Gazelles, howler monkeys, bats and many more creatures have evolved to create calls with deep sonic frequencies that sound as if they come from a much larger animal. Now scientists have proposed this same underlying pressure to exaggerate size might be linked to an even deeper mystery. It could have spurred mammals toward developing the ability to make a wider array of possible calls, to mimic sounds after hearing them and maybe even speech, what scientists call vocal learning. “We are offering one possible way for vocal learning to have evolved,” says Maxime Garcia, a biologist at the University of Zurich in Switzerland who suggested the relationship with his colleague, Andrea Ravignani, in the journal Biology Letters this month. Their idea builds off previous studies on vocal learning in humans. Beyond just opera singers, beatboxers and Michael Winslow from the “Police Academy” movies, we all have some level of control over the frequencies of our voices. “I can tell you to lower your pitch or try to sound big, and you can soound like thissss,” said Katarzyna Pisanski at the University of Lyon in France, affecting a deep voice. © 2020 The New York Times Company

Keyword: Animal Communication; Sexual Behavior
Link ID: 27393 - Posted: 07.31.2020

Ian Sample Science editor Scientists have unravelled the mysterious mechanism behind the armpit’s ability to produce the pungent smell of body odour. Researchers at the University of York traced the source of underarm odour to a particular enzyme in a certain microbe that lives in the human armpit. To prove the enzyme was the chemical culprit, the scientists transferred it to an innocent member of the underarm microbe community and noted – to their delight – that it too began to emanate bad smells. The work paves the way for more effective deodorants and antiperspirants, the scientists believe, and suggests that humans may have inherited the mephitic microbes from our ancient primate ancestors. “We’ve discovered how the odour is produced,” said Prof Gavin Thomas, a senior microbiologist on the team. “What we really want to understand now is why.” Humans do not produce the most pungent constituents of BO directly. The offending odours, known as thioalcohols, are released as a byproduct when microbes feast on other compounds they encounter on the skin. The York team previously discovered that most microbes on the skin cannot make thioalcohols. But further tests revealed that one armpit-dwelling species, Staphylococcus hominis, was a major contributor. The bacteria produce the fetid fumes when they consume an odourless compound called Cys-Gly-3M3SH, which is released by sweat glands in the armpit. Advertisement Humans come with two types of sweat glands. Eccrine glands cover the body and open directly onto the skin. They are an essential component of the body’s cooling system. Apocrine glands, on the other hand, open into hair follicles, and are crammed into particular places: the armpits, nipples and genitals. Their role is not so clear. © 2020 Guardian News & Media Limited

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 27390 - Posted: 07.29.2020

A scientific analysis of more than 2,000 brain scans found evidence for highly reproducible sex differences in the volume of certain regions in the human brain. This pattern of sex-based differences in brain volume corresponds with patterns of sex-chromosome gene expression observed in postmortem samples from the brain’s cortex, suggesting that sex chromosomes may play a role in the development or maintenance of sex differences in brain anatomy. The study, led by researchers at the National Institute of Mental Health (NIMH), part of the National Institutes of Health, is published in Proceedings of the National Academy of Sciences. “Developing a clearer understanding of sex differences in human brain organization has great importance for how we think about well-established sex differences in cognition, behavior, and risk for psychiatric illness. We were inspired by new findings on sex differences in animal models and wanted to try to close the gap between these animal data and our models of sex differences in the human brain,” said Armin Raznahan, M.D., Ph.D., study co-author and chief of the NIMH Section on Developmental Neurogenomics. Researchers have long observed consistent sex-based differences in subcortical brain structures in mice. Some studies have suggested these anatomical differences are largely due to the effects of sex hormones, lending weight to a “gonad-centric” explanation for sex-based differences in brain development. However, more recent mouse studies have revealed consistent sex differences in cortical structures, as well, and gene-expression data suggest that sex chromosomes may play a role in shaping these anatomical sex differences. Although the mouse brain shares many similarities with the human brain, it is not clear whether these key findings in mice also apply to humans.

Keyword: Sexual Behavior; Genes & Behavior
Link ID: 27377 - Posted: 07.21.2020

Ruairi J MacKenzie Research into developing treatments for psychiatric illness is missing out vital data from female animals, producing drugs that aren’t optimized for women and contributing to the failure of clinical trials, said a panel of neuroscientists today at FENS Virtual Forum of Neuroscience. In a press conference, Professor Christina Dalla from the National and Kapodistrian University of Athens, Dr Debra Bangasser from Temple University and Professor Mohammed Milad at New York University Grossman School of Medicine spoke of the impacts of the inequitable use of female animals on their research areas. Dalla reviewed the targeting of the hypothalamic–pituitary–adrenal (HPA) axis using antidepressants. The HPA axis is a major neuroendocrine system that regulates responses to stress and many other bodily processes. Dysfunctions in the HPA axis have long thought to be a factor in the onset of depression, but drugs targeting this axis have roundly failed in clinical trials. Dalla proposed that this failure may partly be the result of pre-clinical studies using male animals, followed by clinical trials that often recruit more women than men. Bangasser and Milad respectively showed how responses to stress and fear also vary between male and female mice. The Forum, held online for the first time, has extensively addressed the representation of women in the field in its program, opening with a Mini-Conference led by the Cajal Club that celebrated the impact of women in the development of neuroscience.

Keyword: Sexual Behavior
Link ID: 27376 - Posted: 07.21.2020

by Chloe Williams A new wireless device activates a mouse’s neurons as it navigates a cage with food, hiding places and other mice, allowing researchers to study social behavior in a realistic environment1. Experiments using this setup suggest that oxytocin has distinct effects in different contexts — which may be particularly important as researchers explore the hormone’s value as a potential treatment for autism. The device makes use of optogenetics, a technique in which researchers use pulses of light to activate or silence neurons. Autism researchers have used the approach to manipulate neural circuits in mice, but traditional optogenetic devices involve a fiber-optic cable, which tethers the animal and interferes with social interactions. Other wireless devices have been able to activate neurons without a tether, but researchers have mostly used them to study social behavior involving just two mice interacting for only about 15 minutes in an otherwise empty cage — a scenario that fails to capture a full range of mouse behaviors2. The new wireless device, powered by two watch batteries, consists of a light-emitting diode attached to an optical fiber that is implanted into the brain. It has an on-off switch that allows researchers to control it remotely using a magnet placed inside the cage. Using this setup, researchers can modulate brain activity in a group of mice as they roam for days through a cage that has hiding places, platforms, a nest, food and water. The device’s designers tested it in mice engineered to express light-sensitive proteins in part of the hypothalamus. This region produces the hormone oxytocin, generally thought to reduce aggression and enhance social bonds. When delivered as a nasal spray, it improves social skills in some people with autism. © 2020 Simons Foundation

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 27369 - Posted: 07.16.2020

As we open computers to connect with each other remotely, motor neurons in our spinal cord are opening synaptic pathways to connect with our muscles physically. We rarely think about these electrical signals passing back and forth between computers or our neurons and muscles, until those signals are lost. Kennedy’s disease, a neuromuscular degenerative disease, affects 1 in 40,000 men every year. Little progress has been made in understanding its biological basis since it was identified in the 1960s, but one promising lead may be a family of proteins known as neurotrophic factors. MSU scientists Cynthia Jordan, professor in the College of Natural Science Neuroscience Program, and Katherine Halievski, former Ph.D. student in Jordan’s Lab and lead author, published a benchmark study in the Journal of Physiology describing the key role of one of these proteins in Kennedy’s disease: Brain-Derived Neurotrophic Factor (BDNF). “There were stories that neurotrophic factors could slow down neurodegenerative diseases, but where they fell short was really understanding how they slow down the disease,” Jordan explained. “Where this paper and Katherine’s work stand alone is in using classic neuroscience techniques to understand how BDNF improved neuromuscular function at the cellular level.” Motor neurons are cells that carry signals from the brain to every muscle in the body — fast twitch muscles that perform quick, high impact movements such as jumping, and slow-twitch muscles that sustain long contractions such as standing. At each step in the pathway — from the neuron, along the synaptic pathway and to the muscle — BDNF supports the process, giving both neurons and muscles what they need to connect, survive and thrive. © Michigan State University

Keyword: Movement Disorders; Hormones & Behavior
Link ID: 27320 - Posted: 06.24.2020