Adolescent impatience increases as testosterone levels rise

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Do estrogen levels affect the willingness to share?

Date:September 17, 2015

Source:Goethe-Universität Frankfurt am Main

Summary:Fluctuating hormone levels change a woman’s social behaviour over the course of the menstrual cycle. Mood swings and irritability before the period as well as a greater interest in sex during ovulation are well known. Now psychologists have discovered that the willingness to share one’s own resources with strangers also fluctuates with hormone levels. Women exhibit a higher willingness to cooperate during and shortly after menstruation — this is the result of two online studies involving over 400 German and US American women.

To qualify for the study, the participants had to have a natural menstrual cycle, in other words not be using hormone-based contraceptives, had to not be pregnant and not have entered menopause yet. The researchers compared the willingness to cooperate between women in the time during and shortly after menstruation (early follicular phase), when the levels of the hormones estrogen and progesterone are low, and a few days after ovulation (midluteal phase), when the estrogen and progesterone levels are especially high. The hormone levels were estimated based on the self-reported day in the cycle.

The researchers measured the subjects’ individual willingness to cooperate using a well-established psychological scale, the “Social Value Orientation.” To do so, they asked the women to divide fictitious money between themselves and another person who was a complete stranger to them.

“Numerous studies have shown that people who exhibit a high willingness to share in this test also donate money more often and in larger amounts in real life, take the train instead of the car to work more often and are more willing to compromise in negotiations than people with a less pronounced pro-social value orientation,” Christine Anderl, lead author of the study, explains.

The two studies showed that the women were significantly more inclined to share their own resources with a stranger during and shortly after menstruation than they were a few days after ovulation.

The greater the cycle-dependent level of the “female” sex hormone estrogen, the lower the willingness to share of the women on a purely statistical basis. “While we are firmly convinced that the variation in the willingness to share over the course of the cycle is a real and systematic effect, we still have to determine whether or not it is really caused by estrogen as the present data suggest,” Christine Anderl tells us.

“This matches the findings of other research groups, who were able to show that hormones such as oxytocin and the “male” sex hormone testosterone affect the willingness to cooperate in humans,” Prof. Sabine Windmann from the Institute for Experimental Psychology 2 at the Goethe University commented. How strongly the cycle-dependent fluctuations in the willingness to cooperate affect the day-to-day life of women and which areas of life are particularly affected by this will have to be researched in further studies.

However, the researchers have already found initial evidence which suggests that the described effects also occur when the subjects are using real money. These results are also interesting in light of hormonal contraception. Little is currently known about how synthetic hormones act on the receptors in the brain and what effect they have on the behaviour of women.


Story Source:

The above post is reprinted from materials provided by Goethe-Universität Frankfurt am Main. Note: Materials may be edited for content and length.


Journal Reference:

  1. Anderl, C., Hahn, T., Notebaert, K., Klotz, C., Rutter, B., & Windmann, S. Cooperative preferences fluctuate across the menstrual cycle. Judgment and Decision Making, Vol. 10, No. 5, September 2015, pp. 400-406

Benefits of Social Grooming in Wild Chimpanzees: Hormone Oxytocin Facilitates Cooperation

Jan. 23, 2013 — Animals which maintain cooperative relationships show gains in longevity and offspring survival. However, little is known about the cognitive or hormonal mechanisms involved in cooperation. Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have now found that cooperative relationships are facilitated by an endocrinological mechanism involving the hormone oxytocin, even when these are between non-kin.


They collected urine samples of 33 chimpanzees from Budongo Forest, Uganda, and measured their urinary oxytocin levels after single episodes of a specific cooperative behavior, mutual grooming. The result: Oxytocin levels were higher after grooming with cooperation partners compared with non-cooperation partners or after no grooming, regardless of genetic relatedness or sexual interest. This suggests that in chimpanzees oxytocin, which acts directly on neural reward and social memory systems, plays a key role maintaining social relations beyond genetic ties and in keeping track of social interactions with multiple individuals over time.

In non-human primates and other social animals strong and enduring social bonds are typically seen between genetically related individuals but also, occasionally, between non-kin, same-sex individuals. Although such relationships are typically defined by high rates of cooperative behaviors, how they are maintained over time is still unclear. In humans and other social mammals the neuropeptide hormone oxytocin plays a central role in facilitating bonding between kin and mating partners. Catherine Crockford, Roman Wittig and colleagues of the Max Planck Institute for Evolutionary Anthropology have now analyzed the role of this hormone in the social relationships between wild chimpanzees.

To this end the researchers observed social interactions – like mutual grooming – in a group of wild chimpanzees from Budongo Forest in Uganda and non-invasively collected urine samples of the 33 female and male adult group members on plastic bags or leaves. They determined the level of the hormone oxytocin before and shortly after the animals had been grooming with each other and found that oxytocin levels were especially high in chimpanzees who had been grooming with a “bond partner”,  a cooperation partner, irrespective of whether this bond partner happened to be their kin or not. On the other hand, the level of urinary oxytocin was much lower in chimpanzees who had been grooming with a “non-bond partner”, with whom they did not share a cooperative relationship, or in animals who had not been grooming at all. Furthermore, the researchers found that the animal’s sex or age, grooming duration and other factors did not have a significant influence on urinary oxytocin levels.

“Our results demonstrate that a rise in oxytocin was dependent upon the combined effects of social grooming with a bond partner”, says Catherine Crockford of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “Crucially, oxytocin levels were similarly high after grooming with non-kin and kin bond partners. This suggests that, in chimpanzees, oxytocin plays a key role in maintaining social relations beyond immediate genetic ties”.

“This is the first study that measures the levels of the hormone oxytocin on wild animals in a non-invasive way”, says Roman Wittig of the Max Planck Institute for Evolutionary Anthropology. “We have developed a tool with which cross-species comparisons that link underlying physiology and behavior can eventually be made of social mammals in their natural environment”. In future field research this tool will be used to compare single behaviors – like other cooperative  or aggressive behaviors–by measuring how they differ from each other hormonally.

 

Story Source:

The above story is reprinted from materials provided byMax-Planck-Gesellschaft.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. C. Crockford, R. M. Wittig, K. Langergraber, T. E. Ziegler, K. Zuberbuhler, T. Deschner. Urinary oxytocin and social bonding in related and unrelated wild chimpanzees.Proceedings of the Royal Society B: Biological Sciences, 2013; 280 (1755): 20122765 DOI: 10.1098/rspb.2012.2765
Max-Planck-Gesellschaft (2013, January 23). Benefits of social grooming in wild chimpanzees: Hormone oxytocin facilitates cooperation. ScienceDaily. Retrieved January 28, 2013, from http://www.sciencedaily.com/releases/2013/01/130123094251.htm

How Repeated Aggression Triggers Social Aversion in Mice

Jan. 18, 2013 — One of the mechanisms involved in the onset of stress-induced depression has been highlighted in mice by researchers from CNRS, Inserm and UPMC (1). They have determined the role of the corticosterone (stress hormone) receptor, in the long-term behavioral change triggered by chronic stress. In mice subject to repeated aggressions, this receptor participates in the development of social aversion by controlling the release of dopamine (2), a key chemical messenger. If this receptor is blocked, the animals become “resilient”: although anxious, they overcome the trauma and no longer avoid contact with their fellow creatures.


This work is published in Science on 18 January 2013.

In vertebrates, stress triggers a rapid release of glucocorticoid hormones, corticosterone in rodents and cortisol in humans. This hormone modifies the expression of numerous genes in such a way that the individual can best respond to the cause of stress. However, chronic or excessive stress can lead to depression, anxiety and social behavioral difficulties. Understanding the mechanisms involved is an important challenge in the treatment of stress-related psychiatric illnesses.

The researchers already suspected that the emergence of depressive symptoms caused by stress brought into play not only the stress hormone but also the dopamine neurons releasing this neurotransmitter, which is vital in controlling mood. To better understand this interdependence, the researchers subjected a group of mice to repeated attacks by stronger, aggressive congeners. After about ten days, the mice showed signs of anxiety and strong social aversion. In fact, when faced with a new congener, the aggressed mice preferred to avoid any contact. This social aversion is considered as a marker of depression.

The researchers repeated the experiment, but this time with various mouse strains in which the corticosterone receptor was absent in certain populations of neurons. In this way, they discovered that mice without this receptor in dopamine-sensitive neurons did not develop social aversion. Although anxious following repeated attacks, they did not however avoid contact with their fellow creatures. These rodents were thus more “resilient,” in other words more resistant to stress, than “wild” mice.

In response to an aggression, a release of dopamine is always observed. However, scientists have noticed that, in mice without the corticosterone receptor in dopamine-sensitive neurons, this release is considerably reduced. In normal mice, dopamine-sensitive neurons thus control the release of this neurotransmitter through a feedback mechanism. In order to show that this release of dopamine triggers the development of social aversion, the researchers blocked the activity of dopamine-producing neurons. As a result, interest in congeners was restored in mice subject to aggression. Dopaminergic activity is therefore crucial for the appearance of social aversion.

This study shows the important role of the stress hormone in the onset of social aversion induced by repeated traumas. More generally, it partially reveals the neurobiological mechanisms and the cascade of reactions that underlie the onset of depression. These results could lead to new therapeutic prospects for treating depression by revealing alternative targets for medicines, particularly with regard to the dopaminergic system.

(1) More precisely, this work was conducted by a team from the laboratory “Physiopathologie des Maladies du Système Nerveux Central” (CNRS/Inserm/UPMC), in collaboration with the laboratory “Neurobiologie des Processus Adaptatifs” (CNRS/UPMC)

(2) Dopamine is a neurotransmitter, in other words a substance that modulates the activity of neurons in the brain.

 

Story Source:

The above story is reprinted from materials provided byCNRS (Délégation Paris Michel-Ange).

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. J. Barik, F. Marti, C. Morel, S. P. Fernandez, C. Lanteri, G. Godeheu, J.-P. Tassin, C. Mombereau, P. Faure, F. Tronche. Chronic Stress Triggers Social Aversion via Glucocorticoid Receptor in Dopaminoceptive Neurons.Science, 2013; 339 (6117): 332 DOI:10.1126/science.1226767
CNRS (Délégation Paris Michel-Ange) (2013, January 18). How repeated aggression triggers social aversion in mice. ScienceDaily. Retrieved January 27, 2013, from http://www.sciencedaily.com/releases/2013/01/130118064727.htm

Red Wine Could Mask Testosterone Levels, Experts Warn

Jan. 7, 2013 — Red wine could give athletes and players a boost in the sports arena by increasing the amount of performance-enhancing hormone testosterone in their bodies, according to researchers from London’s Kingston University.


 

However not only could the beverage help them to trophy success, it could also allow them to beat anti-doping tests. A team led by Professor Declan Naughton, from the University’s School of Life Sciences, found that red wine might reduce the amount of testosterone excreted by the body, which could distort the findings of drug tests taken from urine samples.

Testosterone is a naturally-occurring steroid hormone present in both men and women. It can increase muscle mass, boost stamina and speed up recovery. Sportspeople, however, are prohibited from taking it, or a synthetic version of it, to try to gain a competitive edge.

Although red wine is not a banned substance away from the sports field, Professor Naughton’s team has referred its findings to the World Anti-Doping Agency because of the newly-discovered side effect of potential change to the amount of testosterone in the body.

“Previous research has shown the effect over-the-counter anti-inflammatory drugs can have on enzymes,” Professor Naughton explained. “Since many of these drugs are derived from plants, we decided to look at the effect particular foods and beverages can have on enzymes involved in testosterone excretion. We chose green tea and then red wine because both have a huge variety of natural molecules and we wanted to see if they affected the amount of testosterone excreted in urine.”

The team found that a compound in red wine, known as quercetin, partially blocked the action of an enzyme called UGT2B17, which looks for testosterone and then sends a message to the kidneys to excrete it.

Professor Naughton stressed that the research had so far been conducted in test tube experiments and had yet to be trialled on humans. “A full clinical study would be needed to determine the effects on people but, if the same results were found, it would confirm that compounds in red wine can reduce the amount of testosterone in urine and give a boost to testosterone levels,” he explained.

The effect of red wine on an individual would vary because of factors such as weight, fitness, health and diet, making it hard to estimate how much was needed to improve performance, Professor Naughton said.

Teetotallers are not exempt from the effects. In fact, the alcohol content of red wine has very little impact because non-alcoholic molecules are responsible for inhibiting testosterone excretion.

The team also found the results were the same for red wine extract in supplement form. The active compounds such as quercetin are found in many foodstuffs as well as supplements.

The findings have been published in leading international journal Nutrition. The research follows an earlier study from Professor Naughton’s team which showed that green and white tea could also inhibit testosterone excretion.

 

Story Source:

The above story is reprinted from materials provided byKingston University.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Carl Jenkinson, Andrea Petroczi, Declan P Naughton. Red wine and component flavonoids inhibit UGT2B17 in vitroNutrition Journal, 2012; 11 (1): 67 DOI:10.1186/1475-2891-11-67
Kingston University (2013, January 7). Red wine could mask testosterone levels, experts warn. ScienceDaily. Retrieved January 10, 2013, from http://www.sciencedaily.com/releases/2013/01/130107161424.htm

An Embryo That Is Neither Male nor Female: Impact of Three Unexpected Sex Determination Factors Analyzed

Jan. 3, 2013 — So, is it a girl or a boy? This is the first question parents ask at the birth of an infant. Though the answer is obvious, the mechanism of sex determination is much less so. Researchers at the University of Geneva (UNIGE) attempt to shed light on this complex process by identifying the crucial role played by insulin and IGF1 and IGF2 growth factors, a family of hormones known for its role in metabolism and growth. In the absence of these factors at the time of sex determination, embryos do not differentiate into either male or female and have no adrenal glands. The results of this study, published in the journal PLOS Genetics, allow us to better understand sexual development and will eventually improve diagnosis and genetic counseling practices for individuals with disorders of sex development.


 

In mammals, sexual development is a long process beginning at conception when the sperm’s transmission of an X or Y sex chromosome will determine the genetic sex of the embryo. The following developmental stages will translate this genetic sex into gonadal sex, that is, either ovaries or testes, which will secrete hormones that will masculinize or feminize the fetus.

The intention of the study conducted by Serge Nef, Professor at the Department of Genetic Medicine and Development at UNIGE, is to better understand the first stages of sexual development.

Growth, metabolism and reproduction

The researchers were interested in the role of a class of hormones, insulin-like growth factors (IGFs), and their receptors in cells. These factors, known to be involved in the regulation of metabolism and growth, also have a key role in the regulation of reproductive capacities of the individual, whether male or female. Reproductive function is, in fact, closely linked to metabolism and growth. This is actually quite logical: the growth of an individual cannot progress normally without adequate energy intake and there is no point in reproducing if this caloric intake is insufficient. This may explain why some women with anorexia have anovulatory cycles and may suffer from infertility. Conversely, people with morbid obesity also have significant disturbances in their fertility. Though it is now recognized that the interactions between metabolism, growth and reproductive capacity are regulated by common factors such as insulin and IGFs, Professor Nef’s study shows that these interactions are even more important than previously believed because the insulin and IGF receptors are also essential for primary sex determination in mammals.

To analyze the impact of these hormones on sex determination, Professor Nef’s group used genetically modified mice. The scientists genetically inactivated the receptors for insulin and IGFs in mouse embryos. They then discovered that in the absence of these factors, at the time of sex determination, the gonads of mutant embryos were unable to develop into testes or ovaries. As such, the embryo and its gonads remained stuck in a fully undifferentiated state for several days demonstrating the essential role of these hormones and growth factors in sexual differentiation.

In humans, cases of disorders of sex development are relatively common with about 1 newborn in every 3000 births being affected. Unfortunately, in the majority of cases, the genetic causes of such alterations remain unexplained. “This study provides a better understanding of the basic mechanisms of sexual development and is a step forward towards a better understanding of the causes of sexual ambiguities, which often remain unknown,” states Professor Nef. “The research we are conducting will provide the opportunity to refine and improve clinical diagnosis of individuals with disorders of sex development.”


Story Source:

The above story is reprinted from materials provided byUniversité de Genève, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Jean-Luc Pitetti, Pierre Calvel, Yannick Romero, Béatrice Conne, Vy Truong, Marilena D. Papaioannou, Olivier Schaad, Mylène Docquier, Pedro Luis Herrera, Dagmar Wilhelm, Serge Nef. Insulin and IGF1 Receptors Are Essential for XX and XY Gonadal Differentiation and Adrenal Development in MicePLoS Genetics, 2013 DOI:10.1371/journal.pgen.1003160
 

 

Université de Genève (2013, January 3). An embryo that is neither male nor female: Impact of three unexpected sex determination factors analyzed. ScienceDaily. Retrieved January 10, 2013, from http://www.sciencedaily.com/releases/2013/01/130103192445.htm

Gene Variant Linked to Active Personality Traits Also Linked to Human Longevity

Jan. 3, 2013 — A variant of a gene associated with active personality traits in humans seems to also be involved with living a longer life, UC Irvine and other researchers have found.

A variant of a gene associated with active personality traits in humans seems to also be involved with living a longer life, UC Irvine and other researchers have found. (Credit: © Alex Koch / Fotolia)

This derivative of a dopamine-receptor gene — called the DRD4 7R allele — appears in significantly higher rates in people more than 90 years old and is linked to lifespan increases in mouse studies.

Robert Moyzis, professor of biological chemistry at UC Irvine, and Dr. Nora Volkow, a psychiatrist who conducts research at the Brookhaven National Laboratory and also directs the National Institute on Drug Abuse, led a research effort that included data from the UC Irvine-led 90+ Study in Laguna Woods, Calif. Results appear online in The Journal of Neuroscience.

The variant gene is part of the dopamine system, which facilitates the transmission of signals among neurons and plays a major role in the brain network responsible for attention and reward-driven learning. The DRD4 7R allele blunts dopamine signaling, which enhances individuals’ reactivity to their environment.

People who carry this variant gene, Moyzis said, seem to be more motivated to pursue social, intellectual and physical activities. The variant is also linked to attention-deficit/hyperactivity disorder and addictive and risky behaviors.

“While the genetic variant may not directly influence longevity,” Moyzis said, “it is associated with personality traits that have been shown to be important for living a longer, healthier life. It’s been well documented that the more you’re involved with social and physical activities, the more likely you’ll live longer. It could be as simple as that.”

Numerous studies — including a number from the 90+ Study — have confirmed that being active is important for successful aging, and it may deter the advancement of neurodegenerative diseases, such as Alzheimer’s.

Prior molecular evolutionary research led by Moyzis and Chuansheng Chen, UC Irvine professor of psychology & social behavior, indicated that this “longevity allele” was selected for during the nomadic out-of-Africa human exodus more than 30,000 years ago.

In the new study, the UC Irvine team analyzed genetic samples from 310 participants in the 90+ Study. This “oldest-old” population had a 66 percent increase in individuals carrying the variant relative to a control group of 2,902 people between the ages of 7 and 45. The presence of the variant also was strongly correlated with higher levels of physical activity.

Next, Volkow, neuroscientist Panayotis Thanos and their colleagues at the Brookhaven National Laboratory found that mice without the variant had a 7 percent to 9.7 percent decrease in lifespan compared with those possessing the gene, even when raised in an enriched environment.

While it’s evident that the variant can contribute to longevity, Moyzis said further studies must take place to identify any immediate clinical benefits from the research. “However, it is clear that individuals with this gene variant are already more likely to be responding to the well-known medical adage to get more physical activity,” he added.

First author Deborah Grady, Maria Corrada, Valentina Ciobanu, Alexandra Moyzis, Chuansheng Chen and Dr. Claudia Kawas of UC Irvine; Diana Shustarovich and Gene-Jack Wang of Brookhaven; David Grandy of Oregon Health & Science University; Marcelo Rubinstein of Argentina’s National Scientific & Technical Research Council; and Qi Dong of Beijing Normal University also contributed to the study, which was supported by the U.S. Department of Energy, the National Institute on Aging, and the National Institute on Alcohol Abuse & Alcoholism intramural program.

 

Story Source:

The above story is reprinted from materials provided byUniversity of California – Irvine.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. D. L. Grady, P. K. Thanos, M. M. Corrada, J. C. Barnett, V. Ciobanu, D. Shustarovich, A. Napoli, A. G. Moyzis, D. Grandy, M. Rubinstein, G.-J. Wang, C. H. Kawas, C. Chen, Q. Dong, E. Wang, N. D. Volkow, R. K. Moyzis. DRD4 Genotype Predicts Longevity in Mouse and Human.Journal of Neuroscience, 2013; 33 (1): 286 DOI:10.1523/JNEUROSCI.3515-12.2013
 

 

University of California – Irvine (2013, January 3). Gene variant linked to active personality traits also linked to human longevity.ScienceDaily. Retrieved January 9, 2013, from http://www.sciencedaily.com/releases/2013/01/130103151515.htm