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6 Fascinating Facts About Oxytocin, the "Love Hormone"

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The hormone oxytocin is often referred to as the “love hormone” or the “bonding hormone” because of its observed effects on our relationships. It's released by the hypothalamus during physical intimacy, and during breastfeeding to facilitate mother-child bonding. It also helps us trust one another—as Irina Conboy, associate professor of bioengineering at UC Berkeley, puts it, “this is the hormone that makes your heart melt when you see kittens, puppies and human babies.” But it’s not that straightforward, and many of oxytocin’s effects seem to contradict the presumption that it turns us into blubbering piles of love. Here, a look at some of the many things this molecule can do.

1. It helps turn off fear.

Earlier this month, researchers at the University of Bonn Hospital discovered that oxytocin inhibits the brain’s fear center. In the study, scientists induced fear in subjects by showing them a series of images, 70 percent of which were accompanied by a small electric shock to the hand. Half the subjects then received an oxytocin nasal spray and were shown the same images again, but without the electric shock. Those treated with oxytocin were less afraid of the shock, and the areas of their brains associated with fear were less active. The finding suggests oxytocin could be used to treat anxiety disorders in the future.

2. It may be the cause of your mommy issues.

Oxytocin has been shown to influence how men remember their mother’s affection toward them as children. While under the influence of the hormone, men with strong attachments and happy memories of their mother had these memories heightened, and recalled being closer to her as a kid. This was to be expected, but researchers were surprised to find oxytocin did not enhance positive memories for men who were less attached to their mothers. Instead, the hormone brought bad memories to the forefront, causing men to remember their mothers as less caring. "The fact that oxytocin did not make all participants remember their mother as more caring, but in fact intensified the positivity or negativity of the men's pre-existing memories, suggests that oxytocin plays a more specific role in these attachment representations,” says researcher Jennifer Bartz, Assistant Professor of Psychiatry at Mount Sinai School of Medicine.

3. It makes us cheaters and liars

In one study, participants were asked to predict the outcome of a coin toss and self-report their accuracy. Correct guesses resulted in money, which would be split between team members. Predictably, a financial reward encouraged participants to lie about their success rate. But a dose of oxytocin made them lie even more, and without hesitation. “This is the best evidence yet that oxytocin is not the ‘moral molecule,’” said Carsten de Dreu from the University of Amsterdam, who co-led the study.

4. It makes your dog like you more.

Humans aren’t the only animals affected by oxytocin. One study suggests the hormone makes dogs more friendly toward their owners. Researchers administered oxytocin to 16 adult dogs of different breeds and watched their behavior, paying specific attention to “bonding” behavior like sniffing, nudging, licking, and playing. "We found that after receiving the oxytocin spray, dogs displayed more affiliative behaviors and paid more attention to their owners than during the controls," said the study’s lead author Teresa Romero. The substance may someday be useful in helping abused dogs trust their new, loving owners.

5. It helps heal age-related ailments.

As mice age, the amount of oxytocin in their blood decreases. But what does that mean for their health? Researchers injected oxytocin under the skin of elderly mice with damaged muscles and discovered the muscles healed much faster than those of mice left untreated. “The action of oxytocin was fast,” said Christian Elabd, the study’s co-author. “The repair of muscle in the old mice was at about 80 percent of what we saw in the young mice.” Researchers aren’t sure yet when oxytocin levels drop in humans, or by how much, but they hope it could be used to treat some of our age-related ailments. “Aging is a natural process,” said Irina Conboy, associate professor of bioengineering at UC Berkeley, “but I believe that we can meaningfully intervene with age-imposed organ degeneration, thereby slowing down the rate at which we become progressively unhealthy.”

6. It could help treat eating disorders.

In one study, researchers found that oxytocin nasal spray helped patients suffering from anorexia stop obsessing over things like food and body image. “Oxytocin reduces patients' unconscious tendencies to focus on food, body shape,” said Professor Youl-Ri Kim from Inje University in Seoul, South Korea. This “hints at the advent of a novel, ground-breaking treatment option for patients with anorexia."

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Here's What Actually Happens When You're Electrocuted
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Benjamin Franklin was a genius, but not so smart when it came to safely handling electricity, according to legend. As SciShow explains in its latest video, varying degrees of electric current passing through the body can result in burns, seizures, cessation of breathing, and even a stopped heart. Our skin is pretty good at resisting electric current, but its protective properties are diminished when it gets wet—so if Franklin actually conducted his famous kite-and-key experiment in the pouring rain, he was essentially flirting with death.

That's right, death: Had Franklin actually been electrocuted, he wouldn't have had only sparks radiating from his body and fried hair. The difference between experiencing an electric shock and an electrocution depends on the amount of current involved, the voltage (the difference in the electrical potential that's driving the current), and your body's resistance to the current. Once the line is crossed, the fallout isn't pretty, which you can thankfully learn about secondhand by watching the video below.

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Big Questions
Does Einstein's Theory of Relativity Imply That Interstellar Space Travel is Impossible?
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Does Einstein's theory of relativity imply that interstellar space travel is impossible?

Paul Mainwood:

The opposite. It makes interstellar travel possible—or at least possible within human lifetimes.

The reason is acceleration. Humans are fairly puny creatures, and we can’t stand much acceleration. Impose much more than 1 g of acceleration onto a human for an extended period of time, and we will experience all kinds of health problems. (Impose much more than 10 g and these health problems will include immediate unconsciousness and a rapid death.)

To travel anywhere significant, we need to accelerate up to your travel speed, and then decelerate again at the other end. If we’re limited to, say, 1.5 g for extended periods, then in a non-relativistic, Newtonian world, this gives us a major problem: Everyone’s going to die before we get there. The only way of getting the time down is to apply stronger accelerations, so we need to send robots, or at least something much tougher than we delicate bags of mostly water.

But relativity helps a lot. As soon as we get anywhere near the speed of light, then the local time on the spaceship dilates, and we can get to places in much less (spaceship) time than it would take in a Newtonian universe. (Or, looking at it from the point of view of someone on the spaceship: they will see the distances contract as they accelerate up to near light-speed—the effect is the same, they will get there quicker.)

Here’s a quick table I knocked together on the assumption that we can’t accelerate any faster than 1.5 g. We accelerate up at that rate for half the journey, and then decelerate at the same rate in the second half to stop just beside wherever we are visiting.

You can see that to get to destinations much beyond 50 light years away, we are receiving massive advantages from relativity. And beyond 1000 light years, it’s only thanks to relativistic effects that we’re getting there within a human lifetime.

Indeed, if we continue the table, we’ll find that we can get across the entire visible universe (47 billion light-years or so) within a human lifetime (28 years or so) by exploiting relativistic effects.

So, by using relativity, it seems we can get anywhere we like!

Well ... not quite.

Two problems.

First, the effect is only available to the travelers. The Earth times will be much much longer. (Rough rule to obtain the Earth-time for a return journey [is to] double the number of light years in the table and add 0.25 to get the time in years). So if they return, they will find many thousand years have elapsed on earth: their families will live and die without them. So, even we did send explorers, we on Earth would never find out what they had discovered. Though perhaps for some explorers, even this would be a positive: “Take a trip to Betelgeuse! For only an 18 year round-trip, you get an interstellar adventure and a bonus: time-travel to 1300 years in the Earth’s future!”

Second, a more immediate and practical problem: The amount of energy it takes to accelerate something up to the relativistic speeds we are using here is—quite literally—astronomical. Taking the journey to the Crab Nebula as an example, we’d need to provide about 7 x 1020 J of kinetic energy per kilogram of spaceship to get up to the top speed we’re using.

That is a lot. But it’s available: the Sun puts out 3X1026 W, so in theory, you’d only need a few seconds of Solar output (plus a Dyson Sphere) to collect enough energy to get a reasonably sized ship up to that speed. This also assumes you can transfer this energy to the ship without increasing its mass: e.g., via a laser anchored to a large planet or star; if our ship needs to carry its chemical or matter/anti-matter fuel and accelerate that too, then you run into the “tyranny of the rocket equation” and we’re lost. Many orders of magnitude more fuel will be needed.

But I’m just going to airily treat all that as an engineering issue (albeit one far beyond anything we can attack with currently imaginable technology). Assuming we can get our spaceships up to those speeds, we can see how relativity helps interstellar travel. Counter-intuitive, but true.

This post originally appeared on Quora. Click here to view.

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