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This May Be Why You Crave That Burger

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You’re minding your own business when it hits you: the overwhelming desire for a juicy burger. Where did that sudden meat-need come from? Scientists at Johns Hopkins University may have an answer: a circuit inside your brain that seems to cause protein cravings. The researchers published their findings in the journal Science.

Animals like us need nutrients like protein in order to keep going. Many scientists believe that food cravings are our bodies’ way of motivating us to seek those nutrients out. Yet the exact neurological source of these craving impulses has been something of a mystery.

The authors of the current study started very, very small, looking at cells and circuits in the brains of fruit flies. Activities like mating can increase a fly’s protein cravings, so the researchers decided to focus on female flies that had recently had sex. The scientists monitored the flies' little brains while withholding the bugs’ favorite protein-rich meal of yeast. As the flies’ protein hunger increased, the researchers saw a small circuit of neurons they dubbed DA-WED light up.

To double-check that these cells were in fact craving-related, the scientists shut them down, then offered the recently mated females access to as much yeast as they wanted. But while the circuits were off, the yeast just didn’t seem all that appealing.

Shutting down the DA-WED cells didn’t make the flies drink any less water, nor did it make them eat less in general. They just didn’t feel like getting their yeast on.

These are early findings yet. More research will be needed to confirm the craving/brain cell link in flies, and we’ll definitely need more experiments before we can say the same is true in people. And the average burger also contains two other addictive substances: fat and refined carbohydrates (in the bun).

Still, this paper is an interesting start.

“Further characterization of these and related circuit mechanisms should help delineate the fundamental principles governing protein-specific hunger,” the authors say. “A better understanding of how animals choose to consume protein may also have implications for the treatment of obesity.”

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Feeling Down? Lifting Weights Can Lift Your Mood, Too
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There’s plenty of research that suggests that exercise can be an effective treatment for depression. In some cases of depression, in fact—particularly less-severe ones—scientists have found that exercise can be as effective as antidepressants, which don’t work for everyone and can come with some annoying side effects. Previous studies have largely concentrated on aerobic exercise, like running, but new research shows that weight lifting can be a useful depression treatment, too.

The study in JAMA Psychiatry, led by sports scientists at the University of Limerick in Ireland, examined the results of 33 previous clinical trials that analyzed a total of 1877 participants. It found that resistance training—lifting weights, using resistance bands, doing push ups, and any other exercises targeted at strengthening muscles rather than increasing heart rate—significantly reduced symptoms of depression.

This held true regardless of how healthy people were overall, how much of the exercises they were assigned to do, or how much stronger they got as a result. While the effect wasn’t as strong in blinded trials—where the assessors don’t know who is in the control group and who isn’t, as is the case in higher-quality studies—it was still notable. According to first author Brett Gordon, these trials showed a medium effect, while others showed a large effect, but both were statistically significant.

The studies in the paper all looked at the effects of these training regimes on people with mild to moderate depression, and the results might not translate to people with severe depression. Unfortunately, many of the studies analyzed didn’t include information on whether or not the patients were taking antidepressants, so the researchers weren’t able to determine what role medications might play in this. However, Gordon tells Mental Floss in an email that “the available evidence supports that [resistance training] may be an effective alternative and/or adjuvant therapy for depressive symptoms that could be prescribed on its own and/or in conjunction with other depression treatments,” like therapy or medication.

There haven’t been a lot of studies yet comparing whether aerobic exercise or resistance training might be better at alleviating depressive symptoms, and future research might tackle that question. Even if one does turn out to be better than the other, though, it seems that just getting to the gym can make a big difference.

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Uncombable Hair Syndrome Is a Real—and Very Rare—Genetic Condition
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Everyone has bad hair days from time to time, but for roughly 100 people around the world, unmanageable hair is an actual medical condition.

Uncombable hair syndrome, also known as spun glass hair syndrome, is a rare condition caused by a genetic mutation that affects the formation and shape of hair shafts, BuzzFeed reports. People with the condition tend to have dry, unruly hair that can't be combed flat. It grows slower than normal and is typically silver, blond, or straw-colored. For some people, the symptoms disappear with age.

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Although there have been only about 100 documented cases worldwide, one of the world's leading researchers on the condition, Regina Betz, of Germany's University of Bonn, believes there could be thousands of others who have it but have not been diagnosed. Some have speculated that Einstein had the condition, but without a genetic test, it's impossible to know for sure.

An 18-month-old American girl named Taylor McGowan is one of the few people with this syndrome. Her parents sent blood samples to Betz to see if they were carriers of the gene mutation, and the results came back positive for variations of PADI3, one of three genes responsible for the syndrome. According to IFL Science, the condition is recessive, meaning that it "only presents when individuals receive mutant gene copies from both parents." Hence it's so uncommon.

Taylor's parents have embraced their daughter's unique 'do, creating a Facebook page called Baby Einstein 2.0 to share Taylor's story and educate others about the condition.

"It's what makes her look ever so special, just like Albert Einstein," Taylor's mom, Cara, says in a video uploaded to YouTube by SWNS TV. "We wanted to share her story with the world in hopes of spreading awareness."

[h/t BuzzFeed]

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