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The Scicurious Brain


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When is comfort most comforting? When you’ve got a specific Oxytocin gene!

The views expressed are those of the author and are not necessarily those of Scientific American.


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Hi. In a few minutes I’d like you to stand up and give a short public speech to a judgmental group of people. The speech will be about the current national and international effects of Marbury v Madison, with particular focus on violations of interstate commerce. You have 15 minutes to prepare and the speech will have to be 15 minutes long. I hope you’ve done your research.

Nervous yet? If you are, you’re not alone. Fear of public speaking (glossophobia, or just stage fright) is one of the most common fears in the Western world. But it’s ok. We’re going to have you sit with your loved one, who will be able to give you encouragement as you prepare.

Do you feel a little bit better? I bet you do. But do you really, actually feel better? Does your body react to stress differently when you’ve got a loved one with you to help you out?

It turns out that it might. At least, if you’ve got a specific kind of oxytocin receptor gene.


(Oxytocin. Image via Wikipedia)

(And don’t worry, I was kidding about the speech)

Chen et al. “Common oxytocin receptor gene (OXTR) polymorphism and social support interact to reduce stress in humans” PNAS, 2011.


Oxytocin gets a lot of press. And well it should. Recent findings on oxytocin have shown effects on trust, on generosity, on behaviors in austistic children even. Not to mention all the effects that oxytocin has on parental bonding and on your sex life. While many of these studies have looked at levels of circulating oxytocin, or the effects of giving oxytocin (usually as a nasal spray) on behavior, people have recently started to look at the other side of oxytocin: the oxytocin receptor.

You see, any chemical in the brain (or anywhere else in the body for that matter) which is floating around, is only as good as the receptor it binds to. Which receptors (proteins in cell membranes or in cytoplasm that bind other molecules) it binds to, where those receptors are, how they react, and what they connect to, can really make a world of difference (not to mention fascinating scientists for a lifetime or three). And little changes in receptors, single nucleotide changes in the genes that code for receptor proteins (we call these gene changes single nucleotide polymorphisms or SNPs, which is usually pronounced “snip”), can change the proteins within the genes, and can change how well the receptors work, where they go, and what they do.

And so when you’ve got a receptor for oxytocin, and when you’ve got a SNP in it in humans, of course you want to know what it’s going to do and whether it’s going to change how people act.

In this case, we are looking at the polymorphism rs53576 (don’t you wish we could name them all something interesting and memorable, like Pauline? Sigh, precision above all I guess), which turns a single nucleotide in the oxytocin receptor gene from a G to an A (remember there are four possible nucleotides in DNA: A, G, C, and T). We don’t know yet how exactly this can change the oxytocin receptor’s shape, whether it makes oxytocin bind less well, or what. What we do know is that it’s relatively common in the human population. So this study wanted to see what effect it had on how people respond to stress in the presence of a loved one.

The idea is basically this: oxytocin has a lot to do with social bonding and social behavior. Social bonding is thought to help us during times of stress. If the oxytocin receptor SNP is function, then people with one SNP (say, GG) might do better on measures of anxiety when they have their social bonds around, benefiting more from the social behavior.

And this is where the public speaking coming in. The authors of the study took 173 guys (there might be major sex effects here, oxytocin is known to have very different effects in men and women, so it’s best to study one sex at a time here), and told them they’d be giving a speech shortly. They genotyped all of them to see whether, at this SNP, they were GG, GA, or AA (remember you have two copies of each gene so that will vary). They then left half of each group to prepare alone, while the other half got to prepare with a female friend or female loved one (I wonder if the results would be different with male friends, but I guess that’s for another study). Then, they took levels of cortisol (a stress hormone) right before the public speaking even and right after.

What you can see here are the blood cortisol levels immediately before and after the public speaking event (the bit in grey). Obviously no one liked public speaking very much, the cortisol levels went up significantly in all groups. But you can see that those people with a G in their genotypes (one or two) had a smaller increase in cortisol…but ONLY when they had the social support of their lady friends. The AA group of guys, on the other hand, had cortisol levels that were just as high, regardless of social support.

So that’s cortisol levels, but what about the stress that people were actually feeling?

It turns out that here it made no difference. People were just as nervous with or without the social support. This means that even though the GG/GA guys were less physically stressed, it didn’t really change how they FELT about it.

This may show that the oxytocin receptor gene variant controls how we PHYSICALLY response to stress in the presence or absence of social support. But remember, correlation is not causation and there are a lot of other factors to consider. First is, of course, whether a person even WANTS the social support around. Overt encouragement in the face of stress varies a great deal culturally, and so not all cultures may take this the same way (though all the guys in this study were native Germans). But there are more questions. Did these people differ in how much social support they received in the past? Did their upbringings, even within the culture, vary in terms of social support (probably)? And what does it MEAN that, even though the guys showed differences in stress hormones in the presence of social support, that they all rated it the same way?

Not to mention all the questions this raises about whether exogenous oxytocin helps with this, how the polymorphism affects oxytocin signaling in the first place, and how growing up with one version of this gene could affect responses to stress. And of course, is it the same with male friends? What about in women? What about with family members? What about with other kinds of stress? Are these effects beneficial?

This is a cool study, and provides some very interesting clues as to how changes in oxytocin receptors may affect stress responses, but it’s clear we’re only at the very beginning of understanding how oxytocin really works here. No sure cure for your public speaking fears yet. Ah science, always raising more questions than it answers!

Scicurious About the Author: Scicurious is a PhD in Physiology, and is currently a postdoc in biomedical research. She loves the brain. And so should you. Follow on Twitter @Scicurious.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. JohnDawson 6:25 am 12/19/2011

    I’m not a scientist. But I am an observer. Every year I run 40-50 courses on public speaking in the UK for people who are scared of public speaking.
    I would encourage a wider understanding of public speaking fear . In my understandingwe have to understand the social psychology of a group as well as hormonal influences. In many ways we, as speakers, create our own lack of social bonding by over-interpreting the blank faces in the audience as judgmental, hostile, critical faces.
    When we have a normal one-to-one conversation we create social bonds by showing approval when we are listening (the nod of the head, eye contact, agreeing noises etc). In conversation as a speaker we need those signs of approval. However as public speakers all we get is blank faces with very very few signs of approval. We are mis-interpreting those blank faces hugely. We feel lost, humiliated and judged. As a species we are evolutionary biased towards seeing threat in situations. Useful when we are being attacked in the stone age – not useful in a lecture theatre.
    We need to see blank faces as just listening faces and as public speakers NOT to look for approval in the audience. The route to reducing the fear of public speaking, in my experience, is about re-thinking how we see the audience and how we see ourselves.

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  2. 2. Bonnie Nordby 8:38 am 12/19/2011

    Lol. I actually like assignments for public speaking on topics I know nothing about. I like the intensity of spontaeous public performance. I end up doing my best work that way. What stresses me is the thought of a cocktail party where everyone is scoring points off each others failure. It is only my thought of course. No one is really keeping score. Do you approve?

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  3. 3. Bonnie Nordby 8:55 am 12/19/2011

    One more story: My old rheumatologist Michael Powell was experimenting on using oxytocin injections to treat fibromyalgia. He would inject me during our visit. Of course I fell in complete love with him. I think this could be an interesting avenue for all physicians who would like to increase their level of persuasion in healing. Is it ethical though? With full disclosure of all the possible side effects I think so. I sure felt better after my visits with him. Blush.

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  4. 4. gurueduardo 10:21 am 12/19/2011

    Recently at a friends wedding I noticed that during the ceremony the Maid of Honor looked seriously stressed. After the ceremnony I asked her what the problem was? She said she was seriously stressed out over having to give the toast to the bride.

    I was the MC and told her I would help her relax and make it easier for her to speak in public. When I introduced her she was almost white and looked like she might pass out.

    I then introduced her as the brides best friend and worlds best hugger. Further I told the crowd that if anyone doubted me they could check out her hug for themselves.

    I had set up 4 good looking guys to challenge the claim I had made. One by one the walked up and gave her hug. The crowd roared and everyone was laughing including her. Then when everyone thought my little joke was over the Preacher got up and said he wanted to check for himself.

    Marilyn (maid of honor) was laughing with everyone else. She then went on give a heart warming and beautiful toast to the bride. We were both pleasantly surprised at how well it went.

    A few oxytocin inducing hugs did the trick beautifully. Now I just need to recruit a few hot girls to hug me before my next talk?

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  5. 5. sciencegoddess 9:00 pm 12/21/2011

    Sci, Thanks for this!

    I can’t wait to share this with my students from my human genome course! This study is a great way for them to visualize how knowing about SNPs could be useful in everyday life (and not just about some terrible disease that may befall you)!

    See you soon at #scio12!

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  6. 6. MileHighRoger 2:45 pm 12/28/2011

    It is a nice article. I enjoyed it and learned something about Oxytocin. That aside, I am not a lawyer, but I was curious enough to look up Marbury v. Madison in Wikipedia to see if I thought I could learn enough to talk for 15 minutes. While I did learn something about Marbury v. Madison, I don’t see what Marbury v. Madison has to do with “interstate commerce”, so the assignment would make me even more nervous now than my first impression of it.

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  7. 7. Donzi 8:13 pm 01/3/2012

    I wonder how the study might have resulted with Italians? (No joke; I just think that if one is going to experiment on social bonding that he might want to pick a group with a higher social response than say, Germans.)

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