Tag Archives: #sex

Radar Tracking Uncovers Mystery Of Where Honeybee Drones Have Sex (Biology)

Scientists from Queen Mary University of London and Rothamsted Research have used radar technology to track male honeybees, called drones, and reveal the secrets of their mating behaviours.

The study suggests that male bees swarm together in specific aerial locations to find and attempt to mate with queens. The researchers found that drones also move between different congregation areas during a single flight.

Drones have one main purpose in life, to mate with queens in mid-air. Beekeepers and some scientists have long believed that drones gather in huge numbers of up to 10,000 in locations known as ‘drone congregation areas’. Previous research has used pheromone lures to attract drones, raising concerns that these lures could have inadvertently caused these congregations. This new study is the first ever attempt to track the flight paths of individual drones and observe them in the absence of lures.

Similar mating sites, in which large numbers of males gather, have been observed in other animals but this is the first time males have been observed to move between multiple locations, hinting at the discovery of a new type of animal mating system.

The research is published today in the journal iScience and coincides with the UN designated World Bee Day (20 May), which aims to raise awareness of the importance of pollinators, the threats they face and their contribution to sustainable development.

To track the flight paths of drones, researchers attached a small antenna-like electronic device, known as a transponder, to the back of individual honeybees. When the transponder receives a radar signal from the transmitter, it absorbs its energy and converts it into a higher frequency signal, which is then detected by the radar antenna. As the transponders signal is twice the frequency of the initial signal, it is easily identifiable and cannot be confused with reflections of the original signal from objects in the surrounding environment, such as trees of buildings.

Using this system the researchers are able to track the bee’s position relative to the radar every 3 seconds with an accuracy of around 2m. The team then used the positions of known landmarks within the outdoor experimental field site to determine the true GPS position of each bee.

The scientists found that drones alternated between periods of straight and convoluted, looping flight patterns within a single flight. On further investigation they showed that phases of looping flight were associated with four distinct aerial locations where drones congregated and these specific areas were consistent over a two year period.

The researchers propose that drone congregation areas could function like ‘leks’, mating systems in which large numbers of males gather solely in an attempt to mate. Lek systems are most well known in vertebrates, like deer and grouse, and males are typically faithful to a single lek location.

Dr Joe Woodgate, a Postdoctoral Researcher at Queen Mary and lead author of the study, said: “By using harmonic radar technology to track the bees, we found that individual flight paths show a clear change of behaviour from straight flight to looping flight. Periods of looping flight were clustered in particular locations and repeatable over two years, confirming that stable drone congregation areas, similar to ‘leks’ in other species, do exist.”

“We show that drones frequently visited more than one congregation area on a single flight. This is the first evidence for males of any species routinely moving between lek-like congregations and may represent a new form of lek-like mating system in honeybees.”

Interestingly, the study highlights similarities between the behaviour of drones within these congregation areas to swarms of midges or mosquitos. The researchers observed that when drones are making looping flight in one of these areas, the further they go from the centre, the harder they accelerate back towards it. This creates an apparent force, drawing bees toward the centre and leading to a stable, coherent swarm despite individual drones only spending a short time at each location.

The researchers still don’t understand how the drones find these congregation areas in the first place. Drones are born in Summer and their average lifespan is only around 20 days, so new generations can’t find these areas by following older drones. “Our findings suggest drones locate congregation areas as early as their second ever flight, without apparent extensive search. This implies that they must be able to get the information required to guide them to a congregation from observing the landscape close to their hive. In the future, we will look at how they accomplish this feat,” said Professor Lars Chittka, Professor of Sensory and Behavioural Ecology at Queen Mary and supervisor of the project.

The work was supported by grants from the European Research Council and Engineering and Physical Sciences Research Council (EPSRC).

Dr Joe Woodgate, the lead researcher for the study is also part of the EPSRC-funded ‘Brains on Board’ programme that aims to create robots with the navigational abilities of bees. He added: “We believe that bee-inspired robotics will play a role in improving robotics and artificial intelligence in the future. Understanding how bees select and find distant goals based on their explorations of their surroundings will be important for this.”

Research publication: ‘Harmonic radar tracking reveals that honeybee drones navigate between multiple aerial leks’ Joseph L. Woodgate, James C. Makinson, Natacha Rossi, Ka S. Lim, Andrew M. Reynolds, Christopher J. Rawlings, Lars Chittka, iScience, DOI: https://doi.org/10.1016/j.isci.2021.102499.

Provided by Queensmary University of London

Sex-specific Genetics of Autism (Medicine)

After reviewing a database of gene mutations in children with autism spectrum disorder (ASD), a team of MUSC researchers decided to study a specific gene mutation that likely caused ASD in a girl. They demonstrated that the mutation was damaging to the gene, and that female, but not male, mice lacking a working copy of the gene also showed ASD-associated symptoms. Better understanding the interplay between genetics and sex in ASD could set the stage for developing sex-specific treatments for autism.

The MUSC team was led by Christopher Cowan, Ph.D., the William E. Murray SmartState Endowed Chair in Neuroscience and chair of the Department of Neuroscience, and Ahlem Assali, Ph.D., research assistant professor in the same department. Their findings are published in Nature Neuropsychopharmacology.

One in 54 children is diagnosed with an ASD. Of the children with ASD, four boys are diagnosed for every girl. Individuals with ASD typically have deficits in communication and social interaction and exhibit restricted, repetitive patterns of behavior, activities, or interests. Many people with ASD also present with associated symptoms, such as hyperactivity, attention deficits, epilepsy and intellectual abilities that can range from severely disabled to gifted.

Coronal section of a mouse brain, with several major axonal tracts stained in green. Image courtesy of Dr. Ahlem Assali.

Cowan and Assali investigated the effect of a mutation in the gene, EPHB2, detected in a female patient with autism. EPHB2 is important for forming connections, or synapses, in the brain. The patient had a version of EPHB2 that caused the protein to be cut short. “It’s as if a sentence had a period in the middle instead of the end,” said Cowan. The shortened protein can no longer serve its function, leaving this ASD individual with less functional protein than neurotypical people.

To confirm that this gene can cause autism, Cowan and Assali created mice that had only one of two working copies of EPHB2. They found that these animals showed repetitive behaviors, hyperactivity and learning and memory problems as well as changes in brain cell function.

Cowan and Assali went a step further and divided the animals based on sex. They did this because the child with ASD and the EPHB2 mutation was a female. They found that the female mice showed much stronger behavior symptoms and brain cell dysfunction than the male mice. Understanding the interplay between genetics and biological sex could be important for understanding autism risk and eventually for developing therapeutics.

“We know that 80% to 90% of autism risk is genetic, but this is a very clear-cut case where the gene and the sex of the animal are interacting to alter neurotypical development,” said Cowan.

An excitatory neuron in the mouse cortex, with cell body and spines. Image courtesy of Dr. Ahlem Assali.

Historically, ASD has been diagnosed mostly in boys, so research on ASD has often been biased toward male subjects. The work of Cowan and Assali highlights the importance of sex-specific differences in ASD and the need to examine those differences in research studies that include both sexes. This could set the stage for developing sex-specific treatments for ASD.

“[Examining sex-specific differences in ASD] is the only way we’re going to start to change research inequalities that have happened in the past.” — Dr. Ahlem Assali

“That’s the only way we’re going to start to change research inequalities that have happened in the past,” said Assali.

In future studies, Cowan and Assali hope to explore more deeply the mechanisms of EPHB2 actions in the developing brain. They want to understand why this gene causes symptoms predominantly in girls and female animals and how hormones might affect autism risk. Their aim is to improve the understanding of the interplay between genetics and biological sex in autism, with a view to informing future personalized, sex-specific treatments for ASD.

Featured image: Dr. Christopher Cowan (left) in discussion with Dr. Ahlem Assali (right) in their laboratory. © Sarah Pack, Medical University of South Carolina

Reference: Assali, A., Cho, J.Y., Tsvetkov, E. et al. Sex-dependent role for EPHB2 in brain development and autism-associated behavior. Neuropsychopharmacol. (2021). https://doi.org/10.1038/s41386-021-00986-8

Provided by Medical University of South California

She’s Not Interested in Sex But He Thinks She Is (Psychology)

Women and men misunderstand each other’s signals of friendliness and sexual interest. But these misinterpretations are no surprise to evolutionary psychologists.

Imagine the following scenario: a woman and a man are having a conversation. She is interested in the conversation, and is friendly, smiling and warm. He interprets her behaviour as sexual interest.

Or maybe: a man is sexually attracted to a woman he has just met, and signals this in various ways. She thinks that he is just being friendly.

Recognize these situations? If so, you’re not alone.

We misunderstand each other

In a recent study at the Department of Psychology at NTNU, women reported that men often misinterpret their signals of friendliness as sexual interest. Conversely, the men in the study reported that women often misinterpret their signals of sexual interest as friendliness.

“The results are no surprise, seen from an evolutionary perspective,” researcher Mons Bendixen explains. “The fascinating thing is that our results are identical to a study done in the USA, even though Norway is one of the most gender-equal, sexually liberal countries in the world.”

In most areas of psychology, there is little to no difference between genders: mental capacity, intellectual achievements, food preferences — men and women are all more or less the same. But when it comes to reproduction and challenges related to finding a sexual partner, there are suddenly differences to be found.

Evolutionary psychology is the study of how the human mind has evolved, developed and adapted over time. One thing that evolutionary psychologists are specifically interested in is gendered sexual psychology between cultures and social groups. Seen through the lens of evolutionary psychology, we can better understand why men often wrongly assume that women who smile and laugh during conversation may want to sleep with them.

Men can’t be picky

A man’s ability to reproduce is all about seizing every opportunity. He has to spend both money and time on courtship, which still may not lead to sex. But it costs even more to not try, because then he won’t be able to reproduce.

“A man’s reproductive fitness, meaning the amount offspring he produces, is dependent on how many women he is able to make pregnant. But that’s not how it works for women,” Bendixen explains.

A woman can have sex with multiple men over a short period of time without producing any more children. So for men, it is a low-risk, potentially high-reward situation for men to have sex with women whenever the opportunity presents itself.

On the other hand, the cost is potentially great for a woman if she thinks that a man is more sexually interested than she is. A woman risks pregnancy, birth, nursing and raising the child, as well as lost oppotunities to reproduce with others. Across thousands of generations, women’s psychology has evolved to set the bar higher, which means they need much clearer signals than men before they consider sex.

“Even though these processes aren’t conscious, we can still empirically measure the results,” Bendixen says.

Similar to an American study

The recent study at NTNU included 308 heterosexual participants between the ages of 18 and 30. Fifty-nine per cent of participants were women.

The participants were all heterosexual because sexual intercourse between men and women is necessary for reproduction. Half of the women and 40 per cent of the men were in relationships. The questions were identical to questions asked in a similar American study from 2003. Here are a few examples:

Have you ever been friendly to a person of the opposite gender, and had your actions interpreted as sexual interest? If yes, how many times has this happened?

Have you ever been sexually attracted to someone and shown interest, and had the other person misinterpret your signals as friendliness? If yes, how many times has this happened?

Men misinterpret most often

The results show that both men and women find that their social signals are misinterpreted by the opposite sex. Women in the study answered that they had acted friendly towards a man about 3.5 times over the past year on average, and had this misinterpreted as sexual interest. The men in the study also reported having been misinterpreted by the opposite sex in this way, but far less often.

The results also show that men rarely misinterpret women who actually do signal sexual interest. The study also shows that this is independent of whether or not the person is in a steady relationship or not.

Bedixen points out that Norway is considered to be one of the most gender-equal countries in the world. The USA, on the other hand, where a similar study was done in 2003, is ranked as 20th on the World Economic Forum’s list for equality around the world.

“The fact that the hypothesis in evolutionary psychology is supported even when the study is in a society where gender equality is strong, weakens alternative claims that the social roles of men and women in different cultures determine their psychology in these situations,” he says.

Does not excuse sexual harassment

Researchers at the Department of Psychology are now going to use data collected from high school students to see if the results of this study are also valid for people aged 16-19, and if these miscommunications might lead to sexual harassment.

“Even though evolutionary psychology and our findings can help account for some sexually inappropriate behaviour in men, it doesn’t mean that evolutionary psychologists defend this happening. Measures can be taken to prevent sexual harassment. It will help if we just teach men that a woman who laughs at your jokes, stands close, or touches your arm at a party doesn’t mean that she’s sexually interested, even if you think she is,” Bendixen says.

Featured image: Women and men misunderstand each other all around the world, even in Norway, one of the most gender-equal, sexually liberal countries in the world. © Norwegian Science and Technology

Mons Bendixen (2014) Evidence of Systematic Bias in Sexual Over- and Underperception of Naturally Occurring Events: A Direct Replication of Haselton (2003) in a More Gender-Equal Culture. Evolutionary Psychology, 12(5), 1004-1021.

Provided by Norwegian Science and Technology

A Good Night’s Sleep Could Do Wonders for Your Sex Life (Medicine)

New study suggests that poor sleep quality, not duration, can lead to female sexual dysfunction

The importance of getting a good night’s sleep cannot be overstated. Lack of sleep can lead to a number of health problems and affect a woman’s overall quality of life. A new study suggests that insufficient quality sleep also may lead to problems in the bedroom in the form of female sexual dysfunction. Study results are published online today in Menopause, the journal of The North American Menopause Society (NAMS).

Both sleep and sexual function problems are common in women during midlife. More than 26% of midlife women experience significant sleep symptoms that meet the criteria for insomnia, and sleep problems are reported by nearly half of women during the menopause transition. Up to 43% of women report sexual problems during this same period in their lives.

Multiple studies have been conducted to determine whether there is any association between sleep and sexual function problems. However, most of the previous studies did not consistently evaluate sexual dysfunction with validated tools, nor did they define sexual dysfunction by the presence of sex problems associated with distress.

In this study involving more than 3,400 women (mean age, 53 y), researchers evaluated potential associations between sleep quality and duration and sexual function using validated tools after accounting for factors that may influence both outcomes. They concluded that poor sleep quality, but not sleep duration, was associated with greater odds of female sexual dysfunction. Good sleep quality, in contrast, was linked with sexual activity.

Understanding this association is valuable as clinicians seek to identify potential treatment options for women affected by sleep and sexual problems. Both of these common midlife issues have been determined to adversely affect a woman’s quality of life.

Results are published in the article “Associations of sleep and female sexual function: good sleep quality matters.”

“This study highlights an association between poor sleep quality and sexual dysfunction. These are two common issues for midlife women and asking about and addressing each may contribute to improved quality of life,” says Dr. Stephanie Faubion, NAMS medical director and senior author of the study.

For more information about menopause and healthy aging, visit http://www.menopause.org.

Founded in 1989, The North American Menopause Society (NAMS) is North America’s leading nonprofit organization dedicated to promoting the health and quality of life of all women during midlife and beyond through an understanding of menopause and healthy aging. Its multidisciplinary membership of 2,000 leaders in the field–including clinical and basic science experts from medicine, nursing, sociology, psychology, nutrition, anthropology, epidemiology, pharmacy, and education–makes NAMS uniquely qualified to serve as the definitive resource for health professionals and the public for accurate, unbiased information about menopause and healthy aging. To learn more about NAMS, visit http://www.menopause.org.



Provided by Menopause

Desexing Cats Before 4 Months Can Reduce the Number of Unwanted Kittens (Biology)

Big-data research led by Professor Julia Beatty, Head of the Department of Veterinary Clinical Sciences; Chair Professor of Veterinary Medicine and Infectious Diseases; and Director of the Centre for Companion Animal Health at City University of Hong Kong (CityU), has found that although more than 80% of cats in Australia were desexed, only a fraction have had surgery before reaching puberty, thus creating a “pregnancy gap”. To close this gap and prevent unwanted litters, it is recommended that the age of desexing is before four months.

This recommendation is made by global organisations including the Royal Society for the Prevention of Cruelty to Animals and the International Society for Feline Medicine as unowned domestic cats are fast becoming a global problem, driven by the cats’ phenomenal reproductive success which carries significant economic, animal welfare and biodiversity costs.

Researchers at CityU and the University of Sydney studied anonymous medical records of over 52,000 cats brought into vet clinics, including pet cats, breeding cats, cats owned by shelters, and semi-owned cats in Australia. The research has been published in Scientific Reports.

Despite a clear move towards earlier desexing, the study has found that desexing at four months or younger was carried out in only 21.5% of female cats, while 59.8% of female cats had been desexed by six months of age.

Female cats were less likely than males to be desexed (at all) or to have undergone early-age desexing, which is suboptimal for preventing unwanted litters. A female can give birth to up to three litters of up to six kittens each year.

“This creates a potential pregnancy gap between the time the female cat reaches puberty and the age at surgery,” Professor Beatty said.

Early-age desexing is important to prevent unwanted kittens heading into overburdened and under-resourced shelters or into the stray cat population, which is detrimental to their well-being and puts additional stress on wildlife already impacted by other predators, habitat loss and global warming.

“The benefits of earlier desexing for cats, aside from birth control, include shorter surgery time, a smaller incision and a quicker recovery, and reduced cancer risk,” Professor Beatty added.

Desexing cats before 4 months can close the “pregnancy gap” and reduce the number of unwanted kittens. © CityU

The Jockey Club College of Veterinary Medicine and Life Sciences at CityU works closely with The Society for the Prevention of Cruelty to Animals (Hong Kong) (SPCA) which runs the Cat Colony Care Programme and other animal birth control programmes for local cat-owners.

According to a recent analysis at SPCA clinics, 93% of cats in Hong Kong have been desexed. Although the situation in Hong Kong is a little different to Australia where more cats roam outdoors with more opportunities to breed, important comparisons can be made.

“The SPCA has been very successful in educating owners to have their pets desexed, but there is still work to do in Hong Kong. It is very important for well-meaning carers who feed ‘community cats’ to ensure that those cats are desexed early,” said Dr Jane Gray, Chief Veterinary Surgeon of SPCA.

“Ironically, providing additional food to homeless cats without desexing them can actually make the stray cat problem worse,” said Dr Fiona Woodhouse, Deputy Director of Welfare at SPCA.

“We really hope the research encourages anyone caring for a free-roaming cat in Hong Kong to arrange for that cat to be desexed, preferably before they reach four months of age. This would be a win for cat welfare and would help to reduce the number of unwanted kittens,” said Professor Beatty.

Featured image: Big-data research led by Professor Beatty finds that only a fraction of cats in Australia have had surgery before reaching puberty.

Reference: Mazeau, L., Wylie, C., Boland, L. et al. A shift towards early-age desexing of cats under veterinary care in Australia. Sci Rep 11, 811 (2021). https://www.nature.com/articles/s41598-020-79513-6 https://doi.org/10.1038/s41598-020-79513-6

Provided by CityU

Reindeer Lichens are Having More Sex Than Expected (Botany)

Genetic analysis shows that reindeer lichens reproduce sexually as opposed to asexually more often than researchers thought

In northern Canada, the forest floor is carpeted with reindeer lichens. They look like a moss made of tiny gray branches, but they’re stranger than that: they’re composite organisms, a fungus and algae living together as one. They’re a major part of reindeer diets, hence the name, and the forest depends on them to move nutrients through the ecosystem. They also, at least in parts of Quebec, are having a lot more sex than scientists expected. In a new study in the American Journal of Botany, researchers found that the reindeer lichens they examined have unexpected levels of genetic diversity, indicating that the lichens have been doing more gene-mixing with each other than the scientists would have guessed.

“We were surprised because this species of reindeer lichen had always been considered mainly a clonal species that reproduces asexually,” says Marta Alonso-García, the paper’s lead author and a postdoctoral fellow at Quebec’s Université-Laval. “It doesn’t follow the expected pattern.”

Reindeer lichens swing both ways: they can reproduce sexually via spores, or they can asexually clone themselves. When fungi reproduce sexually, they send out root-like structures toward a neighboring fungus and exchange genetic information when they touch. They then release spores, single cells containing genetic material, which travel on the wind and disperse. When they land, they start growing and produce a new baby fungus that’s genetically distinct from its parents. In asexual clonal reproduction, on the other hand, a piece of the entire lichen (fungus and alga), called the thallus, is pinched off and regrows into a whole organism that’s genetically identical to its parent.

The two reproductive methods have different advantages. “Sexual reproduction is very costly,” says Felix Grewe, the co-director of the Field Museum’s Grainger Bioinformatics Center and a co-author of the study. “You have to find your partner, it’s more difficult than reproducing asexually. But many organisms do it because when you have this combining and mixing of genetic traits, it enables you to weed out negative mutations long-term among other benefits.”

The researchers were examining reindeer lichens (Cladonia stellaris) to learn about their genetic patterns. “We used DNA sequences to tease apart the genetic relationships between populations of this lichen,” says Alonso-García. “We tested whether individuals from northern Quebec (Hudson Bay) were genetically different from those from the South (Parc National des Grands-Jardins, two hours from Québec City). At the same time, due to its important role in the colonization process after a fire, we evaluated lichen genetic diversity along a post-fire succession.”

Lichens can reveal a lot about how wildfires affect ecosystems. “Wildfire is the most significant disturbance in the world’s northernmost forests, and it plays a major role in determining the distribution and composition of plant communities,” says Alonso-García. “In Eastern North America, four successional vegetation stages are generally identified after a fire. During the first stage, crustose lichens and mosses colonize the burned surface. Subsequently, the soil is covered by cup and horn lichens. The landscape remains mostly uniform for around 20 years until the arrival of fruticose lichens which replace the previous vegetation. Cladonia stellaris arrives the last one, usually three or four decades after fire.” By studying genetic variations in reindeer lichens, the researchers hoped to learn how lichens recolonize an area after a fire.

Reference: Alonso‐García, M., Grewe, F., Payette, S., and Villarreal A, J. C.. 2021. Population genomics of a reindeer lichen species from North American lichen woodlands. American Journal of Botany 108( 1): 159– 171. https://doi.org/10.1002/ajb2.1601

Provided by Field Museum

Males and Females Are Programmed Differently in Terms of Sex (Biology)

The evolutionary biologist Olivia Judson wrote, ‘The battle of the sexes is an eternal war.’

Males and females not only behave differently in terms of sex, they are evolutionarily programmed to do so, according to a new study from Oxford, which found sex-specific signals affect behaviour.

Males and females not only behave differently in terms of sex, they are evolutionarily programmed to do so

The new study from Oxford’s Goodwin group from the Department of Physiology, Anatomy and Genetics says, despite sharing very similar genome and nervous system, males and females ‘differ profoundly in reproductive investments and require distinct behavioural, morphological, and physiological adaptations’.

The team argues, ‘In most animal species, the costs associated with reproduction differ between the sexes: females often benefit most from producing high-quality offspring, while males often benefit from mating with as many females as possible. As a result, males and females have evolved profoundly different adaptations to suit their own reproductive needs.’

Males and females have evolved profoundly different adaptations to suit their own reproductive needs

The question for the researchers was: how does selection act on the nervous system to produce adaptive sex-differences in behaviour within the bounds set by physical constraints, including both size and energy, and a largely shared genome?

Today’s study offers a solution to this long-standing question by uncovering a novel circuit architecture principle which allows deployment of completely different behavioural repertoires in males and females, with minimal circuit changes. 

The research team, led by Dr Tetsuya Nojima and Dr Annika Rings, found that the nervous system of vinegar flies, Drosophila melanogaster, produced differences in behaviour by delivering different information to the sexes.

In the vinegar fly, males compete for a mate through courtship displays; thus, the ability to chase other flies is adaptive to males, but of little use to females. A female’s investment is focused on the success of their offspring; thus, the ability to choose the best sites to lay eggs is adaptive to females.

When investigating the different role of only four neurons clustered in pairs in each hemisphere of the central brain of both male and female flies, the researchers found the sex differences in their neuronal connectivity reconfigures circuit logic in a sex-specific manner. In essence, males received visual inputs and females received primarily olfactory (odour) inputs. Importantly, the team demonstrated that this dimorphism leads to sex-specific behavioural roles for these neurons: visually guided courtship pursuit in males and communal egg-laying in females. 

In essence, males received visual inputs and females received primarily olfactory (odour) inputs

These small changes in connectivity between the sexes allowed for the performance of sex-specific adaptive behaviour most suited to these reproductive needs through minimal modifications of shared neuronal networks. This circuit principle may increase the evolvability of brain circuitry, as sexual circuits become less constrained by different optima in male and females.

And it works, the study says, ‘Ultimately, these circuit reconfigurations lead to the same end result—an increase in reproductive success.

‘Our findings suggest a flexible strategy used to structure the nervous system, where relatively minor modifications in neuronal networks allow each sex to react to their surroundings in a sex-appropriate manner.’

Furthermore, this is the first time a firm link between sex-specific differences in neuronal networks have been explicitly linked to behaviour.

According to Professor Stephen Goodwin, ‘Previous high-profile papers in the field have suggested that sex-specific differences in higher-order processing of sensory information could lead to sex-specific behaviours; however, those experiments remained exclusively at the level of differences in neuroanatomy and physiology without any demonstrable link to behaviour. I think we have gone further as we have linked higher-order sexually dimorphic anatomical inputs, with sex-specific physiology and sex-specific behavioural roles.’

We have linked higher-order sexually dimorphic anatomical inputs, with sex-specific physiology and sex-specific behavioural roles

Professor Stephen Goodwin

The researchers maintain ‘evolutionary forces’ have driven these adaptations, ‘Drosophila, males compete for a mate through courtship displays, while a female’s investment is focused on the success of their offspring.’

They conclude, ‘In this study, we have shown how a sex-specific switch between visual and olfactory inputs underlies adaptive sex differences in behaviour and provides insight on how similar mechanisms maybe implemented in the brains of other sexually-dimorphic species.’

Featured image: Sex differences in vinegar flies’ brains’ neural connectivity reconfigures circuit logic in a sex-specific manner. Males receive visual inputs and females’ olfactory (odour) inputs. © University of Oxford

The full paper, A sex-specific switch between visual and olfactory inputs underlies adaptive sex differences in behaviour, joint-first authored by Dr Tetsuya Nojima and Dr Annika Rings, is available to read in Current Biology.

Provided by University of Oxford

What to Do (and Not Do) After You’ve Been Cheated On? (Psychology)

Robert Weiss suggested 12 tips for betrayed partners after infidelity

Betrayed partners, after learning that they’ve been cheated on, are typically in a daze—stunned, angry, sad, and struggling to accept and assimilate the infidelity. Worse still, their thoughts and feelings are an absolute rollercoaster, changing drastically from one moment to the next. As such, they struggle to know how to properly react in the moment, how to envision and think about the future, how to decide whether to stay or go, and sometimes how to just make it through the day without completely losing it.

© Shutterstock, Brovko Serhii

If you and your relationship have been impacted by a partner’s infidelity, and this chaos, confusion, and uncertainty sounds familiar to you, the following tips—six things you should do and six things you should not do—may be helpful.

  1. DO get a full STD screening. As soon as you learn that your partner has been unfaithful (even if you think the infidelity occurred only online), you should visit a clinic or your primary care physician, explaining the situation and asking for a full STD screen.
  2. DON’T have unprotected sex with your partner. No matter what your partner tells you, you absolutely should not have unprotected sex until you and he or she have had a full (and clean) STD screen and you feel confident that he or she has been faithful to you since the screening.
  3. DO investigate your legal rights, even if you hope to heal your relationship and stay together. Wanting to stay together doesn’t mean you will. You should always find out your rights in a potential separation, including financial concerns, property concerns, and parenting issues (if you have kids together).
  4. DON’T jump into long-term decisions. Making life-changing decisions (like impulsively deciding to end your relationship and move across the country) when you are at the height of anger and pain is not a good idea. It is better to put off life-changing decisions until things have calmed down and you’ve had a chance to fully and rationally assess what is best for you. The general rule of thumb is no major changes in the first six months after discovery.
  5. DO get support for yourself. Dealing with a partner’s betrayal requires a level of emotional support that is beyond the life experience of most people. If you are wise, you will seek assistance from people who understand what you’re going through—therapistssupport groups for betrayed partners, family and friends who’ve dealt with similar betrayal.
  6. DON’T try to use sex to fix the problem. Sex is not relationship glue. Sex will not fix the problems wrought by infidelity. Sure, sexual intensity may feel good (and bonding) in the moment, but using sex to assuage emotional pain is a form of mutual denial that moves both you and your partner away from the process of healing. Generally, it is wise to hold off on sex until relationship trust is restored.
  7. DO learn everything you can about infidelity. This educational process helps you to better understand your partner and his or her betrayal and to make healthier decisions in the future.
  8. DON’T make threats you don’t intend to carry out. If you tell your partner that any further betrayal will cause you to leave, make sure you are ready to follow through on that. Otherwise, you diminish your credibility. (It’s usually best to not make threats at all. Say what you feel, but don’t make threats that you might regret later.)
  9. DO trust your feelings and observations. If you feel that you’re being lied to or that your partner is still cheating, trust your intuition. If you don’t see your partner doing what he or she needs to do to make things right, that probably means that things are not getting better.
  10. DON’T take blame for your partner’s behavior. Taking responsibility for your partner’s choice to cheat is not helpful. Nothing that you did or did not do caused the infidelity. It doesn’t matter how you’ve aged, how much weight you’ve gained or lost, or how involved you are with the kids and/or work. You are not responsible for your partner’s betrayal. That is a decision your partner made on his or her own.
  11. DO expect to join your partner in therapy if you want to work things out. It is likely that you want a full accounting of your cheating partner’s behavior. This type of disclosure best occurs in the presence of a neutral professional. If there is a therapist present to help you process the disclosure experience, you reduce the risk of further harm to both you and your relationship.
  12. DON’T stick your head in the sand. If you have an investment in your relationship, you can’t avoid the hard facts of your partner’s betrayal. Pretending the problem will go away on its own can be tempting, but it is ultimately ineffective. You need to address the issue head-on.

Copyright of this article totally belongs to Robert Weiss, (Ph.D., MSW), who is the author of Out of the Doghouse: A Step-by-Step Relationship-Saving Guide for Men Caught Cheating. This article is republished here from psychology today under common creative licenses

Why Do Males Have to Wait For ‘Round 2’? The Reason May be Different From What We Think (Medicine)

If you type into a search engine – “why do men have to wait before having sex again?” – you will very quickly come across Prolactin. This little hormone is thought to be involved in hundreds of physiological processes in the body. Among them is the male post-ejaculatory refractory period. This period begins when a male ejaculates and ends when he recovers his sexual capacity.

If you search a bit more, you’ll see that this theory has even led to the development of so called “treatments”. These promise to shorten the length of a person’s refractory period by reducing their body’s prolactin levels.

Well, here is some bad news for anyone who has bought any such merchandise. A new study in mice by scientists at the Champalimaud Centre for the Unknown in Portugal reveals that prolactin may actually not be the culprit after all. These results were published today (January 4th) in the journal Communications Biology.

The Theory

Ironically, the research project that ended up refuting the theory, never aimed to do so.

“When we started working on this project, we actually set off to explore the theory”, recalls Susana Lima, the principal investigator who led the study. “Our goal was to investigate in more detail the biological mechanisms by which prolactin might generate the refractory period.”

What is the basis of the theory? According to Lima, it emerged through several lines of evidence.

For one, some studies have shown that prolactin is released around the time of ejaculation in humans and rats. And since the refractory period starts right after ejaculation, prolactin seemed like a good candidate. Also, chronic abnormally high levels of prolactin are associated with decreased sexual drive, anorgasmia and ejaculatory dysfunction. Finally, treatment with drugs that inhibit prolactin release in situations of chronically high prolactin, reverse sexual dysfunction.

“These different results all point towards a central role for prolactin in suppressing male sexual behaviour”, says Lima. “However, a direct link between prolactin and the male post-ejaculatory refractory period was never directly demonstrated. Still, this theory has become so widespread that it now appears in textbooks as well as in the popular press.”

Why Not Prolactin?

How did the team end up discovering that the theory was wrong?

To study the role of prolactin in the male refractory period, Lima and her team performed a series of experiments in mice.

“We chose mice as our model animal because the sequence of sexual behaviour in mice is very similar to that of humans”, explains Susana Valente, the first author of the study. “Also, with mice, we can test different strains that exhibit different sexual performance, which makes the data richer. In this case we used two different strains. One that has a short refractory period, and another that has a long one, lasting several days.”

The team began by checking if prolactin levels also increase during sexual activity in male mice. “We measured the levels during the different stages of sexual behaviour using blood samples. And sure enough, they significantly increased during sexual interaction”, says Valente

Once this aspect was confirmed, the researchers moved forward to investigate the relation between prolactin and the length of the animals’ refractory period.

“Our first manipulation was to artificially increase prolactin levels before the animals became sexually aroused. We specifically made sure that the artificial levels matched those we measured during natural sexual behaviour. If prolactin was indeed the cause of the refractory period, the animals’ sexual activity should have decreased”, Valente explains.

To their surprise, this manipulation had no effect on the sexual behaviour of the mice. “Despite the elevation in prolactin levels, both strains of mice engaged in sexual behaviour normally”, she recalls.

Next, the researchers turned to see if blocking prolactin would have the opposite effect on the refractory period. In other words, if animals without prolactin would be more sexually active. Again, the answer was “No”.

“If prolactin was indeed necessary for the refectory period, males without prolactin should have regained sexual activity after ejaculation faster than controls”, Valente points out. “But they did not.”

Back To The Drawing Board

Together, Valente and Lima’s results provide strong counter evidence to the theory claiming prolactin triggers the male refractory period. Still, prolactin is undoubtedly a part of male sexual behaviour. What could be its role?

“There are many possibilities”, says Lima. “For instance, there are studies that point towards a role for prolactin in the establishment of parental behaviour. Also, it’s important to note that prolactin dynamics are quite different in male mice and men. In mice, prolactin levels rise during mating. However, in men, prolactin seems to only be released around the time of ejaculation, and only when ejaculation is achieved. So there may be some differences in its role across species.”

So what is the reason males have to wait before round two?

“Our results indicate that prolactin is very unlikely to be the cause”, says Lima. “Now we can move on and try to find out what’s really happening”, she concludes.

Reference: http://dx.doi.org/10.1038/s42003-020-01570-4

Provided by Champalimaud Center for the unknown