BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: oxytocin

Is there scientific reasoning for women to be stay at home moms?

Is there scientific evidence to prove that women are more maternal than man? According to recent discoveries by researchers at the LSU Department of Biological Sciences, that may be correct.
In a recent study about mice, Ryoichi Teruya, an associate professor at LSU, and his students found that oxytocin activates a specific group of cells in the female mouse brains which is not present in the male mouse brains. Student co-author Ryan LeBlanc used a red pen to meticulously locate each and every oxytocin receptor cell. This research aided greatly in their new discoveries. Oxytocin is seen as a hormone that induces maternal behavior or “love”. This new discovery seems to emphasize that these certain oxytocin receptor cells are only present when estrogen is present. Thus, only women have this maternal instinct. Teruya explains the importance of his study as “[m]any researchers have attempted to investigate the difference between the oxytocin system in females versus males, but no one has successfully found conclusvie evidence until now. Our discovery was a big surprise.” Apparently, the idea that women have an inherent maternal instinct is not just a joke anymore.
This discovery has actually opened the door for many new possible inventions and findings. Mothers with post-partum depression can now potentially have treatments to induce their oxytocin receptor cells in order to help them parent their children better. This would be an extreme breakthrough as children growing up with depressed mothers have many negative effects on their growth development.
As a feminist, I can’t help but wonder if this discovery will only further perpetuate the notion of seperate spheres between men and women where women should stay at home and become a caregiver as their main job. While the idea behind the results of these findings troubles me, I am hopeful about the possible new treatments for post-partum depression as about 10 to 20 percent of women experience this after giving birth. It is interesting to think about husbands who are more maternal than their wives and how that contradicts these findings.

 

 

 

Can Science Explain Love?

Sometimes it’s the greatest feeling in the world. Sometimes it hurts. Although we may never derive a fundamental recipe for it, much of love can be explained by chemistry and biology.

The brain (not the heart!) is responsible for romantic love, which, according to Dr. Helen Fisher at Rutgers University and Katherine Wu at Harvard University, can be broken down into three categories: lust, attraction, and attachment.

Credit: “Hearts” by eflon on Flickr.

Lust is our yearning for “sexual gratification.” This facet of love is grounded in our evolutionary, inherent need to reproduce. Lust is stimulated when the hypothalamus releases “sex hormones (testosterone and estrogen) from the testes and ovaries.”

Whereas lust concerns merely “sexual gratification,” another aspect of love, attraction, encompasses a variety of emotions with regard to a specific person. Attraction leads to the release of the chemicals dopamine and norepinephrine. As anyone whose ever been attracted knows, these chemicals make us “giddy, energetic, and euphoric.” Attraction also stimulates the brain’s reward center, which fires “like crazy when people are shown a photo of someone they are intensely attracted to.” Another hormone, serotonin, is found in low levels in both people with obsessive-compulsive disorder and people those who are experiencing attraction. As a result, scientists have theorized that attraction, and the ensuing low level of serotonin, is responsible for the obsessive infatuation so common in love.

The third aspect of love, attachment, is responsible for intimacy, is a key factor in long-term relationships, and is, of course, mediated by hormones.  The two hormones responsible for attachment, oxytocin and vasopressin, “are found in large quantities during sex, breastfeeding and childbirth,” all activities that are “precursors to bonding.” From this, it is easier to understand the concept of three different aspects of love: the “love” parents feel towards their children is merely the attachment aspect of it, but neither the lust nor the attraction aspect.

Although science can give us a biological basis for it, love, and all of its intricacies, can never be fully explained.

Smile, it makes your dog happy!

Looking at your dog can bring a smile to your face, and looking at you can actually make your dog smile too!  A new study shows that dogs have an emotional response to our facial expressions; dogs like smiling faces, and don’t like angry faces. This is linked to the hormone oxytocin, which influences what and how a dog emotionally experiences what it sees. Oxytocin is a neurotransmitter, dubbed the “love hormone,” so an increase in oxytocin yields a positive reaction.

University of Helsinki researchers studied 43 domestic dogs. The dogs were presented with pictures of unfamiliar faces with happy or angry expressions. Each dog was tested twice; once under the influence of oxytocin, and once without oxytocin. The dogs reactions were determined by their gaze and pupil size, because emotions and attentiveness regulate these reactions (for more information on the relationship between pupil size and emotions, click here). According to the authors, “dogs typically focus on the most remarkable aspect of each situation, such as threatening stimuli in a frightening situation.” Therefore in the trial, dogs will focus on the most remarkable face, either the happy or angry one.

The dogs under the influence of oxytocin were more interested in the smiling faces, and the oxytocin influenced their emotional state, as indicated by their pupil size. They had a larger emotional response to smiling faces under oxytocin, because their pupils were wider. When the dogs weren’t under the influence of oxytocin, their pupils were wider when looking at angry faces, so they were more focused on and had a larger emotional response to the angry faces. The researchers concluded that oxytocin made the angry faces seem less threatening, and the happy faces seem more appealing. This is why the dogs focused on happy faces with oxytocin, and angry faces without oxytocin.

This photo is credited to Max Pixel.

To further the studies, the scientists said that more studies are needed to determine wether the results are only for domestic dogs or if the same reaction occurs with other animals. More studies should also be conducted on dogs with familiar faces, to see if familiarity would change the results of oxytocin on emotional face processing. They also added that in future studies, account of the dog breed, sex, and personality traits should be taken into account because oxytocin does not have uniform effects.

For more information, click here. For the research, click here.

Love Hormone: From Maternal Love to Romantic Attachment to Basic Survival Need

Photo Credit: Roberto Pagani

Introduction

The hormone oxytocin, known as the Love Hormone and sometimes the Cuddle Hormone, is responsible for a plethora of emotional and nervous responses in our bodies. It is a hormone exclusively found in mammals. It causes maternal bonds to form between mothers and their children along with romantic bonds to form between monogamous pairs. Oxytocin controls many social responses that aid bonding and even cause us to feel sympathy. Oxytocin is also known for its ability to cause subjects to feel content, reduce anxiety, and feel calm and secure around one’s mate. The presence of oxytocin is a basic survival adaptation for mammals because it causes them to trust members outside the family unit and therefore permits mating to occur among unrelated members of the same species, thus creating a healthier, more diverse gene pool.

Maternal Love

It’s not surprising that oxytocin is only present in mammals. After all, it controls the release of milk to the nipples during lactation, helps dilate the cervix and trigger labor, and aids formation of bonds between members of species that are vital to the survival of many mammals. One particular bond that oxytocin helps initially form is that between mother

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and offspring. However, one study found that oxytocin levels are higher when first creating a maternal bond than once the bond has been made, therefore oxytocin begins the maternal behavior in the mother, but does not solely maintain it. Researchers have also found that the higher level of oxytocin in mothers during pregnancy, the stronger the bond between mother and child will be once the baby is born and the more maternal the mother will act towards the baby.

Romantic Attachment

Oxytocin is also responsible for causing romantic attachment to form between a monogamous pair. Oxytocin is the cause of the anxiety a person feels when they have been separated from the one they love or, more specifically, have been monogamously paired with. When a monogamous pair is with each other, oxytocin is released. This release causes them to feel content, happier, relaxed, and trusting: basic components of “feeling in love”. However, when the pair is separated for a prolonged period of time, separation anxiety kicks in because the oxytocin which was keeping stress levels low before is no longer being release. Large amounts of oxytocin are released during sexual intercourse and orgasm, hence its name “the love hormone”. Therefore, habitual sexual intercourse between a monogamous pair works to strengthen the romantic bond and causes heightened separation anxiety.

Mammalian Evolutionary Benefits of Oxytocin

The presence of oxytocin is a basic survival adaptation for mammals because it causes stress levels to fall and trust levels to rise, thus it creates the proper conditions for bonding between non-family members or in other words, strangers who they’re instinctually wired to avoid. The social bonding between non-family members aided and maintained by oxytocin is the psychological strategy which enables humans to override our neophobia and to mate with and create a strong, life-long bond with a complete stranger. Mating with non-family members is fundamental to a species survival because it creates a healthier, more diverse gene pool. On top of social bonding that leads to mating, the maternal instincts and maternal bonds are increased by higher levels of oxytocin. The presence of oxytocin in mother is vital for mammalian survival because they have evolved to care for our young and provide them with milk and protection until they are old enough to fend for themselves. Without the oxytocin present during labor, mammals wouldn’t have maternal instincts when offspring is born, the dilation of the cervix would become impaired, milk would not be let down to the nipples during lactation (so there would be no lactation), and mothers wouldn’t have the strong bonds or urges to care for their young.

 

My Opinion and Conclusion

We know that oxytocin causes romantic bonds to form between monogamous humans and causes us to feel sympathy, but what about animals? The “Love Hormone” is known to form maternal bonds between rat mothers and their young and even helps rats form life long monogamous mating bonds. Is it possible that if oxytocin forms bonds and causes sympathy in humans and also causes pair bonding between animals that it could also cause animals such as rats to feel sympathy? Evidence of this would be groundbreaking because it would prove that animals are capable of feeling emotions previously thought to be solely possessed by humans.

 

For More:

http://www.biomedcentral.com/1745-0179/content/2/1/28#B14

http://jn.physiology.org/content/94/1/327.long

http://www.springerlink.com/content/m761t10000r382q5/

http://www.annualreviews.org/doi/abs/10.1146/annurev.neuro.27.070203.144148?url_ver=Z39.88-2003&rfr_dat=cr_pub%3Dpubmed&rfr_id=ori%3Arid%3Acrossref.org&journalCode=neuro

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953948/?tool=pmcentrez

 

 

 

 

 

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