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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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Your $10 Donation Can Help an Underprivileged Child See A Wrinkle in Time for Free
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Disney Enterprises, Inc.

Theater chain AMC is teaming with the Give a Child the Universe initiative to help underprivileged kids see A Wrinkle in Time for free through ticket donations. The initiative was started by Color of Change, a nonprofit advocacy group that designs “campaigns powerful enough to end practices that unfairly hold Black people back, and champion solutions that move us all forward.”

"Color of Change believes in the power of images and supports those working to change the rules in Hollywood so that inclusive, empathetic and human portrayals of black people and people of color are prominent on the screen,” the initiative’s executive director, Rashad Robinson, said in a statement:

Director Ava DuVernay’s A Wrinkle in Time is the perfect subject for the group because, as Robinson puts it, “By casting a black teenage actress, Storm Reid, as the heroine at the center of this story, the filmmakers and the studio send a powerful message to millions of young people who will see someone like them embracing their individuality and strength to save the world.”

The movie touts a diverse cast that includes Mindy Kaling, Oprah Winfrey, Reese Witherspoon, Zach Galifianakis, and Chris Pine. The most important member of the cast, though, is 14-year-old Storm Reid, who plays the main character Meg Murry, a young girl who tries to save her father (Pine) who is trapped in another dimension. The movie is based on the acclaimed 1962 fantasy novel by author Madeleine L'Engle.

If you’d like to donate a ticket (or more), you can just head over to the Give a Child the Universe website and pledge an amount. AMC will provide one ticket to children and teens nationwide for every $10 given to the cause.

And if you’re interested in seeing the movie yourself, A Wrinkle in Time opens on March 9, 2018.

[h/t E! Online]

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Dodo: © Oxford University, Oxford University Museum of Natural History. Background: iStock
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Head Case: What the Only Soft Tissue Dodo Head in Existence Is Teaching Scientists About These Extinct Birds
Dodo: © Oxford University, Oxford University Museum of Natural History. Background: iStock
Dodo: © Oxford University, Oxford University Museum of Natural History. Background: iStock

Of all the recently extinct animals, none seems to excite the imagination quite like the dodo—a fact Mark Carnall has experienced firsthand. As one of two Life Collections Managers at the UK's Oxford University Museum of Natural History, he’s responsible for nearly 150,000 specimens, “basically all the dead animals excluding insects and fossils,” he tells Mental Floss via email. And that includes the only known soft tissue dodo head in existence.

“In the two and a bit years that I’ve been here, there’s been a steady flow of queries about the dodo from researchers, artists, the public, and the media,” he says. “This is the third interview about the dodo this week! It’s definitely one of the most popular specimens I look after.”

The dodo, or Raphus cucullatus, lived only on the island of Mauritius (and surrounding islets) in the Indian Ocean. First described by Vice Admiral Wybrand van Warwijck in 1598, it was extinct less than 100 years later (sailors' tales of the bird, coupled with its rapid extinction, made many doubt that the dodo was a real creature). Historians still debate the extent that humans ate them, but the flightless birds were easy prey for the predators, including rats and pigs, that sailors introduced to the isolated island of Mauritius. Because the dodo went extinct in the 1600s (the actual date is still widely debated), museum specimens are very, very rare. In fact, with the exception of subfossils—the dark skeletons on display at many museums—there are only three other known specimens, according to Carnall, “and one of those is missing.” (The fully feathered dodos you might have seen in museums? They're models, not actual zoological specimens.)

A man standing with a Dodo skeleton and a reconstructed model of the extinct bird
A subfossil (bone that has not been fully fossilized) Dodo skeleton and a reconstructed model of the extinct bird in a museum in Wales circa 1938.
Becker, Fox Photos/Getty Images

Since its extinction was confirmed in the 1800s, Raphus cucullatus has been an object of fascination: It’s been painted and drawn, written about and scientifically studied, and unfairly become synonymous with stupidity. Even now, more than 300 years since the last dodo walked the Earth, there’s still so much we don’t know about the bird—and Oxford’s specimen might be our greatest opportunity to unlock the mysteries surrounding how it behaved, how it lived, how it evolved, and how it died.

 
 

To put into context how old the dodo head is, consider this: From the rule of Oliver Cromwell to the reign of Queen Elizabeth II, it has been around—and it’s likely even older than that. Initially an entire bird (how exactly it was preserved is unclear), the specimen belonged to Elias Ashmole, who used his collections to found Oxford’s Ashmolean Museum in 1677. Before that, it belonged to John Tradescant the Elder and his son; a description of the collection from 1656 notes the specimen as “Dodar, from the Island Mauritius; it is not able to flie being so big.”

And that’s where the dodo’s provenance ends—beyond that, no one knows where or when the specimen came from. “Where the Tradescants got the dodo from has been the subject of some speculation,” Carnall says. “A number of live animals were brought back from Mauritius, but it’s not clear if this is one of [those animals].”

Initially, the specimen was just another one of many in the museum’s collections, and in 1755, most of the body was disposed of because of rot. But in the 19th century, when the extinction of the dodo was confirmed, there was suddenly renewed interest in what remained. Carnall writes on the museum’s blog that John Duncan, then the Keeper of the Ashmolean Museum, had a number of casts of the head made, which were sent to scientists and institutions like the British Museum and Royal College of Surgeons. Today, those casts—and casts of those casts—can be found around the world. (Carnall is actively trying to track them all down.)

The Oxford University Dodo head with scoleric bone and the skin on one side removed.
The Oxford University Dodo head with skin and sclerotic ring.
© Oxford University, Oxford University Museum of Natural History // Used with permission

In the 1840s, Sir Henry Acland, a doctor and teacher, dissected one side of the head to expose its skeleton, leaving the skin attached on the other side, for a book about the bird by Alexander Gordon Melville and H.E. Strickland called The dodo and its kindred; or, The history, affinities, and osteology of the dodo, solitaire, and other extinct birds of the islands Mauritius, Rodriguez and Bourbon. Published in 1848, “[It] brought together all the known accounts and depictions of the dodo,” Carnall says. The Dodo and its kindred further raised the dodo’s profile, and may have been what spurred schoolteacher George Clark to take a team to Mauritius, where they found the subfossil dodo remains that can be seen in many museums today.

Melville and Strickland described Oxford’s specimen—which they believed to be female—as being “in tolerable preservation ... The eyes still remain dried within the sockets, but the corneous extremity of the beak has perished, so that it scarcely exhibits that strongly hooked termination so conspicuous in all the original portraits. The deep transverse grooves are also visible, though less developed than in the paintings.”

Today, the specimen includes the head as well as the sclerotic ring (a bony feature found in the eyes of birds and lizards), a feather (which is mounted on a microscope slide), tissue samples, the foot skeleton, and scales from the foot. “Considering it’s been on display in collections and museums, pest eaten, dissected, sampled and handled by scientists for over 350 years,” Carnall says, “it’s in surprisingly good condition.”

 
 

There’s still much we don’t know about the dodo, and therefore a lot to learn. As the only soft tissue of a dodo known to exist, the head has been studied for centuries, and not always in ways that we would approve of today. “There was quite some consideration about dissecting the skin off of the head by Sir Henry Acland,” Carnall says. “Sadly there have also been some questionable permissions given, such as when [Melville] soaked the head in water to manipulate the skin and feel the bony structure. Excessive handling over the years has no doubt added to the wear of the specimen.”

Today, scientists who want to examine the head have to follow a standard protocol. “The first step is to get in touch with the museum with details about access requirements ... We deal with enquiries about our collections every single day,” Carnall says. “Depending on the study required, we try to mitigate damage and risk to specimens. For destructive sampling—where a tissue sample or bone sample is needed to be removed from the specimen and then destroyed for analysis—we weigh up the potential importance of the research and how it will be shared with the wider community.”

In other words: Do the potential scientific gains outweigh the risk to the specimen? “This,” Carnall says, “can be a tough decision to make.”

The head, which has been examined by evolutionary biologist Beth Shapiro and extinction expert Samuel Turvey as well as dodo experts Julian Hume and Jolyon Parish, has been key in many recent discoveries about the bird. “[It] has been used to understand what the dodo would have looked like, what it may have eaten, where it fits in with the bird evolutionary tree, island biogeography and of course, extinction,” Carnall says. In 2011, scientists took measurements from dodo remains—including the Oxford specimen—and revised the size of the bird from the iconic 50 pounder seen in paintings to an animal “similar to that of a large wild turkey.” DNA taken from specimen’s leg bone has shed light on how the dodo came to Mauritius and how it was related to other dodo-like birds on neighboring islands [PDF]. That DNA also revealed that the dodo’s closest living relative is the Nicobar pigeon [PDF].

A nicobar pigeon perched on a bowl of food.
A nicobar pigeon.
iStock

Even with those questions answered, there are a million more that scientists would like to answer about the dodo. “Were there other species—plants, parasites—that depended on the dodo?” Carnall asks. “What was the soft tissue like? ... How and when did the dodo and the related and also extinct Rodrigues solitaire colonize the Mascarene Islands? What were their brains like?”

 
 

Though it’s a rare specimen, and priceless by scientific standards, the dodo head is, in many ways, just like all the rest of the specimens in the museum’s collections. It’s stored in a standard archival quality box with acid-free tissue paper that’s changed regularly. (The box is getting upgraded to something that Carnall says is “slightly schmancier” because “it gets quite a bit of use, more so than the rest of the collection.”) “As for the specific storage, we store it in vault 249 and obviously turn the lasers off during the day,” Carnall jokes. “The passcode for the vault safe is 1234ABCD …”

According to Carnall, even though there are many scientific and cultural reasons why the dodo head is considered important, to him, it isn’t necessarily more important than any of the other 149,999 specimens he’s responsible for.

“Full disclosure: All museum specimens are equally important to collections managers,” he says. “It is a huge honor and a privilege to be responsible for this one particular specimen, but each and every specimen in the collection also has the power to contribute towards our knowledge of the natural world ... This week I was teaching about a species of Greek woodlouse and the molluscs of Oxfordshire. We know next to nothing about these animals—where they live, what they eat, the threats to them, and the predators that rely on them. The same is true of most living species, sadly. But on the upside, there’s so much work to be done!”

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