Obsessed With Oxytocin

My classmates know it. My friends know it. Almost everyone I meet knows it. It's pretty clear. I am obsessed with oxytocin.

What is oxytocin??

Oxytocin is a peptide hormone and neurotransmitter made in the hypothalamus. To the left is the molecular structure of oxytocin.

From the hypothalymus, oxytocin is either sent to different parts of the brain (acting as a neurotransmitter), or stored in the posterior pituitary for release into the bloodstream as a hormone. Below is a picture of oxytocin in the posterior pituitary waiting to be released (photo from my Tissue and Organ Biology course at Tufts).

But why am I so obsessed with oxytocin?!
In an endocrinology course in undergrad and again in a very recent physiology lecture here at Tufts Med, I learned that oxytocin is used to make the uterus contract during childbirth and to release or "let down" breast milk so mom can nurse baby. That was it. One slide, a few bullets, no big deal, not very exciting. But like most hormones, oxytocin is pleiotropic - it is made by one gene, but does a heck of a lot more than one thing. Oxytocin not only acts on the breast and uterus, it also can affect the brain, kidney, heart, etc. Oxytocin plays a huge part in biological and behavioral components of human life and is vital to successful development, successful relationships, and successful reproduction.


Oxytocin's involvement in human romantic relationships is really what drew me in. This one hormone seemed to explain why life and relationships are the way they are. 

Lucky for me, oxytocin has been gaining popularity recently. It has been dubbed the fantastic nicknames of the "Love Hormone" or "Cuddle Hormone." Scientists are currently studying tons of different ways oxytocin is involved in the function or dysfunction of our bodies, relationships, and minds, and they have started discovering potential ways oxytocin can help people suffering from a variety of problems.

So in this post, I am going to attempt to explain some of the wonderful things oxytocin does. I will try to keep it short, but I am obsessed, so bear with me or skip to a section that interests you!

1. Oxytocin and Bonding

When a baby breastfeeds, oxytocin is released to let down the milk in the mom's breasts. This oxytocin also warms the mother's body so the baby is comfortable. The baby is warm, has cozy cuddly feelings from oxytocin, is receiving some delicious nourishment from mom, and is able to build trust. Meanwhile, mom is being rewarded by oxytocin to continue to nourish, love, coo at, entertain, and protect her baby. Oxytocin also promotes pro-social behavior by increasing gaze to the eye region of the human face. I assume that eye gaze starts during breastfeeding, and continues to promote social interaction throughout life. 

Scientists studying abuse and childhood neglect found that adults that were raised in orphanages or abused during childhood have lower oxytocin levels. They (and I) believe that the early mother-baby relationship is crucial to oxytocin response and human interaction later in life (thanks for all the oxytocin, Mom!).

Oxytocin also promotes social recognition. In rodents, the ability to recognize and process odors of friends and enemies is enhanced by oxytocin. In humans, it helps us remember and recognize faces (way less cool, but hey, probably way more pleasant!). This aspect of oxytocin is crucial to creating and maintaining friendships and relationships. Oxytocin also regulates social memories, displays of friendly as well as aggressive behaviors, and by reducing stress hormones, allows us to trust the faces we see frequently. 

While this is awesome, and a great benefit of oxytocin, we need to be careful. These effects cause us to trust people more readily (on oxytocin, study participants will give strangers more money - generosity hormone?), which could result in being taken advantage of (in any kind of relationship).

For you animal lovers out there, oxytocin levels are also increased in people reporting strong bonds between themselves and their dogs. Annnnnd oxytocin is released when petting animals! 

2. Oxytocin reduces anxiety, fear and stress

When stimulated by positive social interactions (like hugs, hand-holding, cuddling, or smiles), oxytocin calms down the amygdala, reducing fear and anxiety and creating emotional connections. So if you find yourself in a stressful social situation, oxytocin might help you out and calm your nerves. Oxytocin has also been found to reduce levels of cortisol and ACTH - hormones associated with stress.
 

3. Wound healing and oxytocin.

Cortisol inhibits wound healing, and because oxytocin lowers cortisol levels, it may improve wound healing and inflammation. There were a couple of animal studies that showed that paired animals or animals given oxytocin had improved wound healing. And in humans, pain perception is decreased in people with higher oxytocin levels! This effect of oxytocin may be able to explain the health benefits of certain therapies such as massage, aromatherapy, art therapy, and meditation!

4. Love, sex, relationships, & oxytocin. (Why I am posting this on Valentine's Day)

I'm pretty sure my oxytocin levels spiked when I saw this!

Like I said before, this aspect of oxytocin is why I became obsessed. Here is a bit of the Valentine's Day appropriate side of oxytocin...

Love: Animal studies of oxytocin are often done on vole rats - monogamous rats that form long-term bonds and are bi-parental (AKA rats that make bonds the same way we do!). Giving vole rats oxytocin enhanced bonds between the vole rat couples, and giving vole rats oxytocin antagonists disrupted those bonds. One of my oxytocin bloggers (yeah, I have those) wonder if people who cheat on their partners have lower levels of oxytocin than the strictly monogamous... hm...

Oxytocin is partially in charge of partner preference (by way of odor in animals or facial recognition in us), and increases during intense romantic attachment. The "euphoric" feeling of a new relationship is related to higher oxytocin levels (higher than longer relationships in fact). But as the relationship continues every touch, kiss, caress, or sexual experience with someone releases some oxytocin, enhancing trust and increasing the subconscious bond between the two people involved. I think that oxytocin is a key to maintaining a successful relationship by reliving that "euphoria" of a new relationship.

Oxytocin is also released during relationship problems and when relationships end. I like to think of it as craving for something you can no longer have. There is a downside to everything, even oxytocin. But cuddling with a pet, dancing, painting, getting a massage, or getting support from friends (oxytocin releasing activities!) can help alleviate those cravings and partially "cure" the break-up blues! 

Sex: The biggest rush of oxytocin is released during arousal in men and women, peaking at orgasm. Levels go back to pre-arousal levels about thirty minutes later. This hit of oxytocin is akin to a high from ecstacy. In fact, oxytocin activates the same (dopamine) receptors that addictive drugs do, encouraging us to go back for more! 

In male animals, oxytocin increases number of erections (only if testosterone is also present) and decreases time between "mountings." However, at very high levels, the opposite occurs and the male exhibits "sexual satiety" - increased non-sexual attention to the female (post-coital cuddling!). 

Women vs. Men: Women have more oxytocin receptors in their body, and express more oxytocin than men (gives us those fab maternal instincts). Also, oxytocin gene promotors contain estrogen response elements so that estrogen actively encourages oxytocin to hang around in our (female) bodies. I like to think this is why women tend to become more attached to their partners during new relationships than men. I also think it can explain some discrepancies between the way males and females act in relationships and during partner bonding... (I could go on and on about this...)

I have a ton of other theories about how the Valentiney actions of oxytocin explain the relationships I have been in or relationships I have heard about from friends. Because I don't have time, many of you have heard them, and my theories are just theories, I'll stop there with this topic...

5. Oxytocin as a cure.

Patients with schizophrenia have low oxytocin levels in their cerebrospinal fluid (CSF), and scientists think that their dysfunction in gaze and facial emotion processing is related to low oxytocin levels. Animals treated with PCP have similar behavior to schizophrenics, and oxytocin restored their social behavior.

Depression, post-traumatic stress disorder, and OCD also seem to be related to low oxytocin levels. SSRIs (antidepressants) were found to cause a short-term increase in oxytocin in rats. Maybe oxytocin can treat depression?

 
Oxytocin also might decrease blood pressure, reduce body salt content, and act as a pain-killer. Studies are currently being done on the possible uses of oxytocin for fibromyalgia for pain. 

Oxytocin is also being tested as a treatment for sexual dysfunction in both men and women. 

Children with autism, a developmental disorder characterized by decreased social and communication skills, have lower oxytocin levels and higher oxytocin precursor levels. Maybe an enzyme that makes oxytocin is defective? Children with autism are also more likely to have a certain haplotype of oxytocin receptor. In a small study of 15 adults with autism or Aspberger's, IV oxytocin improved social recognition and speech comprehension, and reduced repetitive behavior in autistic patients. Obviously more research should be done, but it seems that oxytocin is somehow involved in autism, and has the potential to be an amazing treatment.

CONCLUSION: 
To sum everything up, oxytocin does a lot of stuff and is super duper awesome and obsession-worthy. I hope you learned a thing or five, and that you now find oxytocin as neat as I do! Feel free to comment with questions or arguments or theories, and I will keep my readers (you) posted on new oxytocin news as I hear it. 

Sources: (I love having access to Journals!)

1.) www.oxytocincentral.com

2.) Waguih, W. I., Kahloon, M., Fakhry, Hala. (2011). Oxytocin role in enhancing well-being: A literature review. Journal of Affective Disorders, 130, 1-9.

3.) Heon-Jin, L. Macbeth, A.H., Pagani, J.H., Young, W.S. (2009) Oxytocin: The great facilitator of life. Progress in Neurobiology, 88, 127-151.

Lisa's Lessons of Late

I have learned some crazy and random things the past few weeks. So I decided to share...

1. Onset of puberty is SUPER YOUNG.
Boys start puberty at age 9, and girls between 7 and 8. I don't know about you, but that's a lot younger than I remember starting puberty. The onset of puberty has been decreasing in the past 175 years and scientists don't know why. I've heard people claim that it's related to environmental toxins, I've even heard the blame land on genetically modified foods. Who knows what is to blame, but puberty starts early!

2. Breastfeeding guidelines.
So people who hate on public breast-feeders are just hating on good moms, because babies should be breastfed 8 to 12 times a day for ten to fifteen minutes per breast. Do the math, that's up to 6 hours a day of breastfeeding. If moms don't want to breastfeed in public, then they better do errands quickly and stay home all the time, because they should be breastfeeding every 1.5 to 3 hours.

**Public Health Note: Breastfeeding is really good for babies, and should not be replaced with formula feeding! It gives babies an immune boost, feelings of warmth and love from mom, and has all the nutrients a baby needs for the first 4 to 6 months of life!

3. The origin of the word hypochondriac.
We are learning about the abdomen, and when we discuss the different structures, we refer to 9 regions created by what looks like a tick-tack-toe board on the abdomen (see photo on left). The "hypochondriac regions" lie beneath, or "hypo," to the cartillage, or "chondriac," of the ribs. In ancient medicine, patients would often come to their doctors with pains in the hypochondriac regions. Sadly for those ancient hypochondriacs, the doctors believed that those regions held anxiety and melancholy, and dismissed the patients even though they may have had serious problems. Today, people who claim that they have bundles of medical problems without any clinically observable information to back it up are still called hypochondriacs.

**Public Health Note II (I know, again): I wonder if current doctors are making the same mistakes their predecessors did by dismissing patients with problems that they can't find answers to.

4. Most of the world is lactose intolerant after early stages of development:
My professor seemed to think that people drinking milk that is not from their mother is a really weird and crazy concept. Some Caucasian groups of people gained the gene for lactose tolerance and were able to survive better with food available somewhere during evolution. So people here are often lactose tolerant, but in most parts of the world, they are not.

As my professor said, "So if you are lactose intolerant, you do not have a disease, you are not a genetic freak. You are normal. Most animals cannot drink milk past an early age, most humans can't drink milk past early stages of development."

On Being Hectic

Two summers ago, Frannie and I spent five weeks in Europe traveling around with a bunch of twenty-somethings on a bus. We met a girl named Kate from Australia and I was fascinated by how many words she used differently than I did. One such word was "hectic." We went out dancing, and at the end of the night she said "tonight was heaps hectic!" I had always considered the word to hold a negative connotation. I would use it to complain about busy and stressful days when nothing went my way. Kate used to word to mean something completely different. Kate meant "tonight was super awesome!"

Lets rewind a little bit. In college, I overextended myself and was involved in literally as many things as I could fit on my plate. Most of the time I was happy with my busy schedule, and whenever I did find fee time I would ended up picking up projects or finding things to do with every minute of my day.

After applying to medical school I decided that I needed a break. I felt like I was always busy and hectic, so I deferred from Tufts for a year. I took up a 9 to 5 volunteer job as an Americorps VISTA in the Service Learning Department of Anne Arundel County Public Schools. After work, I would go home for four to five hours of free time.

What did I learn during my year off? I don't like free time. Now don't get me wrong, I need about an hour or two a day to unwind, relax, cook dinner, maybe watch a tv show, etc, but too much free time is not for me. My AmeriCorps position did not keep me occupied, so I picked up projects and activities to fill my time. I still found that I had too much free time.

So this week was "heaps hectic," both in my meaning and the Aussie meaning of the word. I was busy, stressed out and overwhelmed from 8am in the morning until 1am the next day. But looking back, I had a spectacular week and I learned and accomplished so many things.

I may complain and whine about how stressful my life is and how much I have to do, but last year proved to me that I wouldn't have it any other way. When I get too much free time, I automatically fill it. My friend Alex always used to stop me when I complained to tell me that I asked for my busy life, and she's right. I need to remind myself that this on stressful weeks like this week, and change my concept of the word hectic. I may be busy, but for me, busy is super awesome, heaps hectic!

So I know I'll regret this, but when I complain about how hectic everything is, remind me that that I like hectic. 

*Disclaimer: I don't mean to say that a hectic (busy + awesome) life is always a healthy life - I constantly work on finding a good balance between my personal preference for a busy life with enough free time to remain sane. I just wanted to explain why I often overload myself with extracurriculars and activities. Definitely something I need to continue to work on!