Previous research suggesting it's all about prolactin may be missing the mark.
- Men and other male creatures need time to recover between ejaculations, and scientists have assumed it has to do with an increase in the hormone prolactin after coitus.
- A new study finds that manipulating prolactin levels in mice makes no difference in their sexual behavior.
- The authors suspect more complex interactions may be at the heart of the wait for round two.
PERP<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTI2OTI5MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2OTkyODk5OH0.1M9fAOERqj7uhXoA0owV4diEjUUuMIZ_gxvAsfRdB3A/img.jpg?width=980" id="cd357" class="rm-shortcode" data-rm-shortcode-id="d045e3e22ba8661166825b91be5b95b4" data-rm-shortcode-name="rebelmouse-image" data-width="1440" data-height="960" />
Credit: Julian Hochgesang /Unsplash<p>From an evolutionary standpoint, as the study puts it, "The PERP is thought to allow replacement of sperm and seminal fluid, functioning as a negative feedback system where, by inhibiting too-frequent ejaculations, an adequate sperm count needed for fertilization is maintained." The length of time involved appears to be influenced by a range of factors, including age and the excitement associated with having a new sexual partner.</p><p>Prolactin itself serves a variety of functions in the human body for both sexes. Its most well-known role is to promote lactation—it's released by the female body during nursing. Estrogen triggers its production by the pituitary gland, while dopamine restrains it.</p><p>Though prolactin's other roles remain under investigation, it's also believed to be involved in behavior regulation, and in maintaining the immune, metabolic, and reproductive systems.</p>
No smoking gun<p>The authors write that "the sequence of sexual behavior in the mouse is very similar to the one observed in humans, making it an ideal system to test this hypothesis."</p><p>Therefore, for the study, Lima and her colleagues studied prolactin's role during and after sexual activity for two types of male mice—one type required several days to recover from ejaculation while the other had a relatively short PERP.</p><p>The researchers took blood from the males before they were introduced to female partners from whom they'd been kept separated. Blood was again taken after a preliminary mounting, again after a number of mounts that depended on the male's PERP—five mounts for the slow-recoverers and three for the males with the shorter turnaround time. Finally, blood was taken after ejaculation, which was fairly easy to discern since it was accompanied by what the study calls "stereotypical shivering" in the males, who also fell over afterward.</p><p>The researchers did find that the males' recovery was accompanied by higher levels of prolactin. However, during subsequent experiments in which the scientists boosted prolactin levels prior to sex—which, if the prevailing theory was correct, would have reduced their interest in copulation—no change in their sexual behavior was observed. Says Lima, "Despite the elevation in prolactin levels, both strains of mice engaged in sexual behavior normally."</p><p>Repressing prolactin levels after ejaculation also failed to reduce the males' PER interval. "If prolactin was indeed necessary for the refectory period," says Lima, "males without prolactin should have regained sexual activity after ejaculation faster than controls. But they did not."</p><p>Lima does caution that there are some differences between mice and men when it comes to prolactin dynamics, so more study is warranted.</p>
So, what is going on?<p>Lima suggests that there's likely some complex interaction between the two systems involved in ejaculation: the central brain system that manages desire and the peripheral system that handles the physical aspects of ejaculation.</p><p>At the very least, the research suggests that we don't yet know why men experience their mandatory time-out. "Our results indicate that prolactin is very unlikely to be the cause," Lima summarizes. "Now we can move on and try to find out what's really happening." </p>
Monogamy is often considered a key component of traditional marriages, but it's only half the story.
- Depending on who you ask, monogamy is either essential to a successful marriage or it is unrealistic and sets couples up for failure.
- In this video, biological anthropologist Helen Fisher, psychologist Chris Ryan, former Ashley Madison CEO Noel Biderman, and psychotherapist Esther Perel discuss the science and culture of monogamy, the role it plays in making or breaking relationships, and whether or not humans evolved to have one partner at a time.
- "The bottom line is, for millions of years, there were some reproductive payoffs not only to forming a pair bond but also to adultery," says Fisher, "leaving each one of us with a tremendous drive to fall in love and pair up, but also some susceptibility to cheating on the side."
Positive, romantic thoughts could produce positive, romantic outcomes while dating.
- Fear of rejection, self-doubt, and anxiety are just some of the obstacles humans need to overcome to make a meaningful, romantic connection with another person.
- According to a 2020 project by a group of psychologists at the University of Rochester (and the Israeli-based Interdisciplinary Center Herzliya), humans see possible romantic partners as a lot more attractive if they go into the interaction with a "sexy mindset."
- Across three separate studies, this team discovered that this sexual activation helps people initiate relationships by inducing them to project their desires onto prospective partners.
Being in a frisky mood improves your chances with potential romantic partners<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQzNzk0OC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0Mjc3MDA5NH0.lwJquRq9_gTYX5c_2sRzCBfkyWldjMqCJig_kGCL1uA/img.jpg?width=1245&coordinates=0%2C6%2C0%2C6&height=700" id="d0453" class="rm-shortcode" data-rm-shortcode-id="9a29ad6b50ff3868c867fd2d0a64b8aa" data-rm-shortcode-name="rebelmouse-image" alt="man and woman on date woman" data-width="1245" data-height="700" />
The right mood could land you the right date, according to a new study.
Credit: BlueSkyImage on Shutterstock<p><a href="https://www.eurekalert.org/pub_releases/2020-09/uor-ffm092320.php" target="_blank" rel="noopener noreferrer">According to a 2020 study</a> by a group of psychologists at the University of Rochester (and the Israeli-based Interdisciplinary Center Herzliya), humans see possible romantic partners as a lot more attractive if they go into the interaction with a "sexy mindset."</p><p><a href="https://www.sas.rochester.edu/psy/people/faculty/reis_harry/" target="_blank" rel="noopener noreferrer">Harry Reis</a>, professor of psychology and the Dean's Professor in Arts, Sciences & Engineering at Rochester, and <a href="https://www.idc.ac.il/en/pages/faculty.aspx?username=birnbag" target="_blank" rel="noopener noreferrer">Gurit Birnbaum</a>, a social psychologist and associate professor of psychology at the IDC (Interdisciplinary Center Herzliya) have dedicated decades of their lives to studying the intricate dynamics of sexual attraction and human sexual behavior. </p><p>In <a href="https://www.rochester.edu/newscenter/relationships-uncertainty-are-you-really-in-to-me-323512/" target="_blank" rel="noopener noreferrer">a previous study,</a> the pair discovered that when people feel greater certainty about a romantic partner's interest, they put more effort into seeing that person again. Additionally, this study found people will rate the possible partner as more "sexually attractive" if they knew the person was interested in seeing them again.</p><p><a href="https://www.eurekalert.org/pub_releases/2020-09/uor-ffm092320.php" target="_blank" rel="noopener noreferrer">For this project</a>, Reis and Birnbaum, along with their team, examined what would happen if a person's sexual system is activated by exposing them to brief sexual cues that induced a thought process that included the potential for sex or heightened attraction. </p><p>Across three separate studies, the team discovered that this sexual activation helps people initiate relationships by inducing them to project their desires onto prospective partners. </p><p><strong>Study one: Immediacy</strong></p><p>In the first study, 112 heterosexual participants (between the ages of 20-32) who were not in a romantic relationship were randomly paired with an unacquainted participant of the opposite sex. Participants introduced themselves to each other (speaking about their hobbies, positive traits, career plans, etc.), all while being recorded. </p><p>The team then coded the recorded interactions and searched for nonverbal expressions of immediacy (such as close proximity, frequent eye contact, smiles, etc.) that could indicate interest in starting a romantic relationship. </p><p>In the study, the team determined that the participants exposed to a sexual stimulus before the meeting (versus those exposed to a neutral stimulus) exhibited more immediacy behaviors towards their potential partners and also perceived the partners as more attractive and/or more interested in them. </p><p><strong>Study two: Interest</strong></p><p>In the second study, 150 heterosexual participants (between the ages of 19-30) who were not in a romantic relationship served as a control for the potential partner's attractiveness and reactions. All participants in study two watched the same pre-recorded video introduction of a potential partner of the opposite sex. They then introduced themselves to the partner while being filmed themselves. </p><p>The researchers found that the activation of the sexual system led to participants viewing the potential partner as more attractive as well as more interested in them. </p><p><strong>Study three: How it all ties together</strong></p><p>In the third and final study, the team investigated whether a partner's romantic interest could explain why sexual activation impacts how we view other people's romantic interest in ourselves. </p><p>In this study, 120 single heterosexual participants (between the ages of 21-31) interacted online with another participant who was actually an attractive opposite-sex member of the research team. This was a casual "get-to-know-you" kind of interaction. The participants rated their romantic interest in the other person as well as that person's attractiveness and interest in them.</p><p>Again, the team found that sexual activation increased a person's romantic interest in the other person, which, in turn, predicted that the other person would then be more interested in a romantic partnership as well. </p><p><strong>The takeaway: Positive, romantic thoughts could produce positive, romantic outcomes. </strong></p><p>The basis of this multi-study theory is simple: Having active sexual thoughts arouses romantic interest in a prospective partner and often leads to an optimistic outlook on dating. </p><p>"Sexual feelings do more than just motivate us to seek out partners. It also leads us to project our feelings onto the other person," <a href="https://www.eurekalert.org/pub_releases/2020-09/uor-ffm092320.php" target="_blank">said Reis to Eurekalert</a>. </p><p>Reis goes on to explain, "...the sexual feelings need not come from the other person; they can be aroused in any number of ways that have nothing to do with the other person."</p>
New research reveals that because of an optical illusion, we've been viewing sperm incorrectly for nearly 350 years.
Sebastian Kaulitzki/Science Photo Library via Getty Images
- Since 1677, thanks to an optical illusion caused by viewing them in 2D, science has assumed that sperm move toward an egg by lashing their tails from side to side like an eel.
- A new study that used 3D microscopy devices shows that sperm corkscrew forward like an otter.
- This research could be useful for furthering our understanding about the causes of male infertility by giving us a better idea of the mechanisms that underlie sperms' incredible journey to an egg.
Microscopes were wrong: Sperm corkscrew<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="2bba1faebd6e6d5d81670495a290f57a"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/BQ_3lxlVJ-w?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Now, a team of researchers has finally upended that assumption. A new study published in <a href="https://advances.sciencemag.org/content/6/31/eaba5168" target="_blank" rel="dofollow">Science Advances</a> shows that sperm don't slither like serpents, which is actually an optical illusion. Rather, they corkscrew forward like playful otters.</p><p>Researchers from the United Kingdom and Mexico recently used a high-speed camera and 3D microscopy devices to capture sperm's movement, and what they found will restructure what we understand about one of the most essential biological functions. Rather moving their tail from side to side like a snake, sperms' tails only lash to one side. While this would seemingly cause them to swim in circles, these cells instead rotate their bodies each time their tails lash to the side, thus propelling them in a spiral motion. </p><p>"We were not expecting to find what we found," Hermes Gadêlha, head of the Polymaths Lab at University of Bristol and lead author on the study, <a href="https://www.smithsonianmag.com/science-nature/researchers-discover-how-human-sperm-really-swim-180975453/" target="_blank" rel="noopener noreferrer dofollow">told Smithsonian Magazine</a>. "The aim of the project was 'blue sky' [or broad] research, to understand how sperm moves in three dimensions. And the result has completely changed the belief system that we have."</p><p>So, how did it take us until 2020 to modify van Leeuwenhoek's 17th century assumption? The primary reason that his sperm-model went undisputed for centuries was because researchers have continued to use 2D technology to view sperm. If you were to look at sperm under a modern microscope, you would probably make the same incorrect assumption about their movement that van Leeuwenhoek made. The depth that 3D imaging provided allowed researchers to see that the sperm's body is spinning in a rotated motion, whereas in flat picture it looks like it's simply moving its tail to each side. </p><p>Another problem that has existed for researchers, <a href="https://theconversation.com/sperm-fooled-scientists-for-350-years-they-spin-not-swim-140669" target="_blank" rel="noopener noreferrer dofollow">according to Gadêlha</a>, is that sperm's size and speed make them extremely difficult to observe closely. In fact, they can complete approximately 20 propulsions in less than a second. </p>
Broader implications about reproduction<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzU2MDk4MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MTYwMjY4OH0.3evBQkLlB53d4PpRdhEamnVMOayH1OtIQa17aBjXgJ0/img.jpg?width=1245&coordinates=0%2C26%2C0%2C26&height=700" id="11d55" class="rm-shortcode" data-rm-shortcode-id="7b3b7ddc6b121920db2c5a0938e0e1ad" data-rm-shortcode-name="rebelmouse-image" alt="rendering of sperm surrounding egg" data-width="1245" data-height="700" />
Human eggs "choose" sperm by using a chemical signal to attract certain sperm.
Getty Images<p>As this study highlights, what science reveals to us about the world is constantly in flux as our technology, cultural beliefs, and the questions we ask evolve. This discovery about sperms' true movement builds upon a slew of recent studies that are radically challenging what we know about human reproduction. For example, it was long believed that the human egg had no active role when it came to its interaction with sperm. Earlier this summer, <a href="https://phys.org/news/2020-06-human-eggs-men-sperm.html#:~:text=Human%20eggs%20use%20chemical%20signals%20to%20attract%20sperm.&text=Humans%20spend%20a%20lot%20of,eggs%20can%20%22choose%22%20sperm." target="_blank">a study found</a> that human eggs "choose" sperm by using a chemical signal to attract certain sperm. Last year, <a href="https://theconversation.com/how-mens-damaged-sperm-could-play-significant-role-in-recurrent-miscarriage-109683" target="_blank">another study</a> found that men's sperm, when damaged, can play a larger role in recurrent miscarriages than previously thought.</p><p>While these cultural dynamics are interesting, this new study on sperms' swimming techniques holds some practical implications as well. It could be useful for future research about the causes of male infertility. For example, we now have a better idea of mechanisms that underlie sperms' incredible journey to an egg and that could help scientists understand why some sperm have a more difficult time making it there to successfully procreate.</p>
You may be surprised at how your body and brain react to this type of pleasure.
- An orgasm is described as a feeling of intense pleasure that happens during sexual activity.
- By studying the brain activity of people experiencing orgasms, researchers have been able to pinpoint some of the key changes that occur.
- These changes include heightened sensitivity to areas of the brain that control how we feel pain, making us less sensitive to it.
What really happens in the brain during orgasm?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUzMjAzOS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNzk0MTg3N30.XMncIeu8myjL-bgF936p4NYAmXpCbI7dQl1AXuXBZc0/img.jpg?width=1245&coordinates=0%2C93%2C0%2C93&height=700" id="eaf6a" class="rm-shortcode" data-rm-shortcode-id="309e980e413d58c454f6fed13596917f" data-rm-shortcode-name="rebelmouse-image" alt="3D rendering of hypothalamus lighting up" data-width="1245" data-height="700" />
The hypothalamus, which plays a key role in releasing hormones like dopamine and oxytocin, is one of the regions of the brain that lights up during orgasm.
Image by SciePro on Shutterstock<p><strong>Does the "logical" part of your brain shut down? That's hotly debated.</strong></p><p><strong></strong>There may be a reason why you feel bold and uninhibited during your climax.<br></p><p>"The lateral orbitofrontal cortex becomes less active during sex. This is the part of the brain that is responsible for reason, decision making, and value judgments. The deactivation of this part of the brain is also associated with decreases in fear and anxiety," explains clinical psychologist <a href="https://www.betweenusclinic.com/about-us/" target="_blank">Daniel Sher</a>. </p><p>However, not all experts in the field agree with this widely publicized study's findings. Recent (2017) research suggests otherwise, with results that show that these areas of the brain <a href="https://pubmed.ncbi.nlm.nih.gov/28986148/" target="_blank">did not deactivate within the 10 female participants of this study</a>.</p><p><strong>Parts of your brain associated with memories, touch, and movement may light up. </strong></p><p>Research has found that the hypothalamus, thalamus, and substantia nigra may light up during orgasm. "Dirty Minds: How Our Brains Influence Love, Sex and Relationships" author <a href="http://kaytsukel.com/" target="_blank">Kayt Sukel</a> <a href="https://www.theguardian.com/science/blog/2011/nov/16/orgasm-mri-scanner" target="_blank">was interviewed</a> for her work alongside researchers who studied the effect of an orgasm on the brain while she was in an MRI machine.</p><p>The thalamus helps integrate information about touch, movement, and sexual memories/fantasies. This could explain how you call upon sexual memories and fantasies (or why your imagination is able to be more active) during sexual arousal and peak. </p><p><strong>Oxytocin builds up and is released.</strong></p><p>Oxytocin is defined as a "bonding" hormone. The forming of oxytocin during sex happens in the pituitary glands and it is then released in the hypothalamus. The <a href="https://www.healthline.com/human-body-maps/hypothalamus" target="_blank">hypothalamus</a> plays a key role in many important functions including the releasing of other hormones (like dopamine), regulation of body temperature, controlling of appetite, and of course, the management of sexual behaviors.</p><p><strong>A surge of dopamine is released. </strong></p><p>During orgasm, your brain works hard to produce various hormones, like the aforementioned oxytocin. In that cocktail of hormones is dopamine, which is released at the moment of orgasm. Dopamine is responsible for feelings of pleasure and desire and therefore acts as a motivation to keep experiencing those feelings of pleasure and desire. </p><p>Dopamine is formed <a href="https://thebrain.mcgill.ca/flash/d/d_03/d_03_cr/d_03_cr_que/d_03_cr_que.html" target="_blank">in the part of the brain</a> that receives information from several other areas in order to define if your needs (specifically your human needs) are being satisfied. </p><p><strong>The release of endorphins, oxytocin, and vasopressin make you less sensitive to pain during sex. </strong></p><p>For many, pain and sex go hand in hand. Many people enjoy a little bit of pain during sex, and there is actually a very good reason for this: you're less susceptible to pain during sex. The pituitary gland is activated during sex, which then frees your brain up to release all kinds of endorphins that are able to promote pain reduction. </p><p>An interesting thing to note is that some of the same areas of the brain that are active during sex are also active when you experience pain. <a href="https://pubmed.ncbi.nlm.nih.gov/4000685/" target="_blank">A very interesting 1985 study</a> looked at the correlation between vaginal stimulation and the elevation of pain. </p><p><strong>In people who are unable to feel genital stimulation, the brain may actually be able to "remap" itself. </strong></p><p>People who have suffered lower-body paralysis can still achieve orgasm through stimulation of other body parts such as the nipples. In this case, the brain actually creates new pathways to pleasure that doesn't involve our genitalia. <a href="https://www.seattletimes.com/seattle-news/health/paralyzed-women-rediscover-orgasms/" target="_blank">This Seattle Times article</a> details paralyzed women who were able to rediscover their ability to orgasm through various other sensations.<br></p><p><strong>Having orgasms can keep your brain healthy. </strong></p><p>Because there is a significant increase in blood flow across multiple areas of the brain so dramatically when we achieve orgasm, it's entirely likely that orgasms may have developed in part to keep our brains healthy.</p>
What really happens in the body when you orgasm?<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMzUzMjAzOC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY3MjY5NTA2Nn0.IPva3rC8oSEb-b_JXYYDccKbO47CkWTnPO9BUCgxTlA/img.jpg?width=1245&coordinates=0%2C52%2C0%2C52&height=700" id="6b2af" class="rm-shortcode" data-rm-shortcode-id="648070a56f9fea934d8780dba38bfb1f" data-rm-shortcode-name="rebelmouse-image" alt="woman holding blanket in her hand" data-width="1245" data-height="700" />
What really happens in the body when we orgasm?
Photo by NATNN on Shutterstock<p><strong>Your body swells and becomes more sensitive.</strong></p><p>While men experience the obvious swelling in the genitals due to increased blood flow, women can experience some forms of swelling during sex as well. From your breasts to your vulva, many women experience swelling during sexual arousal and release. </p><p><strong>Your heart rate quickens, which leads to euphoria. </strong></p><p>Of course, your heart rate elevates when you're experiencing orgasm, but along with that, you also experience a blood pressure rise and your breathing rate also increases. Both of these things are considered mild aerobic activity responses and could factor into the kind of euphoria you feel during sexual experiences - similar to a "runners high."</p><p><strong>Muscles in the vagina, anus, and uterus contract and release - like a workout.</strong></p><p>Not only is your pulse racing, but you may also be working out some of the muscles in your body (aside from the ones you're using to physically have sex). </p><p>According to <a href="https://www.bustle.com/p/9-things-that-happen-to-your-body-when-you-have-orgasm-that-you-never-realized-8487239" target="_blank">Bustle</a>, "Increased blood flow to the genitals during orgasm also maintains the integrity of the smooth muscle that lines the vagina, rectum and connective tissue between the penile shaft and scrotum."</p><p><strong>Orgasms may improve allergy symptoms or clear blocked nasal passages.</strong></p><p>"Orgasms can be effective at opening blocked nasal passages and can alleviate some allergy and congestion symptoms," according to sexologist and clinical professional counselor Dr. Laura Deitsch.</p>