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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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Feeling Anxious? Just a Few Minutes of Meditation Might Help
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Some say mindfulness meditation can cure anything. It might make you more compassionate. It can fix your procrastination habit. It could ward off germs and improve health. And it may boost your mental health and reduce stress, anxiety, depression, and pain.

New research suggests that for people with anxiety, mindfulness meditation programs could be beneficial after just one session. According to Michigan Technological University physiologist John Durocher, who presented his work during the annual Experimental Biology meeting in San Diego, California on April 23, meditation may be able to reduce the toll anxiety takes on the heart in just one session.

As part of the study, Durocher and his colleagues asked 14 adults with mild to moderate anxiety to participate in an hour-long guided meditation session that encouraged them to focus on their breathing and awareness of their thoughts.

The week before the meditation session, the researchers had measured the participants' cardiovascular health (through data like heart rate and the blood pressure in the aorta). They evaluated those same markers immediately after the session ended, and again an hour later. They also asked the participants how anxious they felt afterward.

Other studies have looked at the benefits of mindfulness after extended periods, but this one suggests that the effects are immediate. The participants showed significant reduction in anxiety after the single session, an effect that lasted up to a week afterward. The session also reduced stress on their arteries. Mindfulness meditation "could help to reduce stress on organs like the brain and kidneys and help prevent conditions such as high blood pressure," Durocher said in a press statement, helping protect the heart against the negative effects of chronic anxiety.

But other researchers have had a more cautious outlook on mindfulness research in general, and especially on studies as small as this one. In a 2017 article in the journal Perspectives on Psychological Science, a group of 15 different experts warned that mindfulness studies aren't always trustworthy. "Misinformation and poor methodology associated with past studies of mindfulness may lead public consumers to be harmed, misled, and disappointed," they wrote.

But one of the reasons that mindfulness can be so easy to hype is that it is such a low-investment, low-risk treatment. Much like dentists still recommend flossing even though there are few studies demonstrating its effectiveness against gum disease, it’s easy to tell people to meditate. It might work, but if it doesn't, it probably won't hurt you. (It should be said that in rare cases, some people do report having very negative experiences with meditation.) Even if studies have yet to show that it can definitively cure whatever ails you, sitting down and clearing your head for a few minutes probably won't hurt.

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Scientists Use a CT Scanner to Give Whales a Hearing Test
Ted Cranford
Ted Cranford

It's hard to study how whales hear. You can't just give the largest animals in the world a standard hearing test. But it's important to know, because noise pollution is a huge problem underwater. Loud sounds generated by human activity like shipping and drilling now permeate the ocean, subjecting animals like whales and dolphins to an unnatural din that interferes with their ability to sense and communicate.

New research presented at the 2018 Experimental Biology meeting in San Diego, California suggests that the answer lies in a CT scanner designed to image rockets. Scientists in San Diego recently used a CT scanner to scan an entire minke whale, allowing them to model how it and other whales hear.

Many whales rely on their hearing more than any other sense. Whales use sonar to detect the environment around them. Sound travels fast underwater and can carry across long distances, and it allows whales to sense both predators and potential prey over the vast territories these animals inhabit. It’s key to communicating with other whales, too.

A CT scan of two halves of a dead whale
Ted Cranford, San Diego State University

Human technology, meanwhile, has made the ocean a noisy place. The propellers and engines of commercial ships create chronic, low-frequency noise that’s within the hearing range of many marine species, including baleen whales like the minke. The oil and gas industry is a major contributor, not only because of offshore drilling, but due to seismic testing for potential drilling sites, which involves blasting air at the ocean floor and measuring the (loud) sound that comes back. Military sonar operations can also have a profound impact; so much so that several years ago, environmental groups filed lawsuits against the U.S. Navy over its sonar testing off the coasts of California and Hawaii. (The environmentalists won, but the new rules may not be much better.)

Using the CT scans and computer modeling, San Diego State University biologist Ted Cranford predicted the ranges of audible sounds for the fin whale and the minke. To do so, he and his team scanned the body of an 11-foot-long minke whale calf (euthanized after being stranded on a Maryland beach in 2012 and preserved) with a CT scanner built to detect flaws in solid-fuel rocket engines. Cranford and his colleague Peter Krysl had previously used the same technique to scan the heads of a Cuvier’s beaked whale and a sperm whale to generate computer simulations of their auditory systems [PDF].

To save time scanning the minke calf, Cranford and the team ended up cutting the whale in half and scanning both parts. Then they digitally reconstructed it for the purposes of the model.

The scans, which assessed tissue density and elasticity, helped them visualize how sound waves vibrate through the skull and soft tissue of a whale’s head. According to models created with that data, minke whales’ hearing is sensitive to a larger range of sound frequencies than previously thought. The whales are sensitive to higher frequencies beyond those of each other’s vocalizations, leading the researchers to believe that they may be trying to hear the higher-frequency sounds of orcas, one of their main predators. (Toothed whales and dolphins communicate at higher frequencies than baleen whales do.)

Knowing the exact frequencies whales can hear is an important part of figuring out just how much human-created noise pollution affects them. By some estimates, according to Cranford, the low-frequency noise underwater created by human activity has doubled every 10 years for the past half-century. "Understanding how various marine vertebrates receive and process low-frequency sound is crucial for assessing the potential impacts" of that noise, he said in a press statement.

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