Scientists Identify Cells in the Brain That Control Anxiety

iStock
iStock

People plagued with the uncomfortable thoughts and sensations characteristic of anxiety disorders may have a small group of cells in the brain to blame, according to a new study. As NPR reports, a team of researchers has identified a class of brain cells that regulates anxiety levels in mice.

The paper, published in the journal Neuron, is based on experiments conducted on a group of lab mice. As is the case with human brains, the hippocampus in mouse brains is associated with fear and anxiety. But until now, researchers didn't know which neurons in the hippocampus were responsible for feelings of worry and impending danger.

To pinpoint the cells at work, scientists from Columbia University, the University of California, San Francisco, and other institutions placed mice in a maze with routes leading to open areas. Mice tend to feel anxious in spacious environments, so researchers monitored activity in the hippocampus when they entered these parts of the maze. What the researchers saw was a specialized group of cells lighting up when the mice entered spaces meant to provoke anxiety.

To test if anxiety was really the driving factor behind the response, they next used a technique called optogenetics to control these cells. When they lowered the cells' activity, the mice seemed to relax and wanted to explore the maze. But as they powered the cells back up, the mice grew scared and didn't venture too far from where they were.

Anxiety is an evolutionary mechanism everyone experiences from time to time, but for a growing portion of the population, anxiety levels are debilitating. Generalized anxiety disorder, social anxiety disorder, and panic disorder can stem from a combination of factors, but most experts agree that overactive brain chemistry plays a part. Previous studies have connected anxiety disorders to several parts of the brain, including the hippocampus, which governs memory as well as fear and worry.

By uncovering not just how the brain produces symptoms of anxiety but the individual cells behind them, scientists hope to get closer to a better treatment. There's more work to be done before that becomes a possibility. The anxiety cells in mice aren't necessarily a perfect indicator of which cells regulate anxiety in humans, and if a new treatment does eventually come from the discovery, it will be one of many options rather than a cure-all for every patient with the disorder.

[h/t NPR]

New Cross-Bred Cosmic Crisp Apples Can Stay Fresh for Up to a Year

Cosmic Crisp
Cosmic Crisp

Healthy snackers know only too well the disappointment that comes with biting into what looks like a deliciously crisp apple and getting a mouthful of mealy mush instead. It’s just one of the pome fruit’s many potential issues—they also brown quickly, bruise easily, and don’t last as long as whatever bag of chips you might be tempted to reach for instead.

Enter the Cosmic Crisp, a Washington-grown patented hybrid apple that could be the answer to all your apple-related complaints. According to New Atlas, researchers at Washington State University began breeding the new variety as a cross between Enterprise and Honeycrisp apples in 1997, and it’s officially hitting stores now.

cosmic crisp apple on tree
Cosmic Crisp

Not only does a Cosmic Crisp apple resist bruising and browning better than other kinds of apples, it also boasts an exceptionally long storage life. In a controlled atmosphere, it should stay fresh for a full year—meaning you’ll soon be able to enjoy a crisp, satisfying snack in the middle of March, when out-of-season apples usually leave much to be desired. In your own refrigerator, Cosmic Crisp apples are good for about six months, and they’ll even last for several weeks if you leave them out at room temperature. The long shelf life might cut down on the number of apples that you end up tossing in the trash because they went bad before you got around to eating them.

In a 2012 report published in the American Society for Horticultural Science journal HortScience, the Washington State University researchers found that a group of 114 consumers rated the Cosmic Crisp apple, or WA 38, higher than Fuji apples in sweetness, sourness, flavor intensity, crispness, firmness, juiciness, and overall acceptance. The apple's website even suggests that bakers can reduce the amount of added sugar in recipes that contain Cosmic Crisps.

The Cosmic part of its name comes from the whitish specks on the apple’s skin, which reminded taste testers of a starry sky. In reality, those specks are lenticels—porous openings that allow the apple to exchange gases with its environment.

If you don’t see Cosmic Crisp apples in your grocery store yet, here’s a simple trick for keeping any apples fresh for longer.

[h/t New Atlas]

The Reason So Many Babies Are Conceived in Winter

yurizhuravov/iStock via Getty Images
yurizhuravov/iStock via Getty Images

Does it feel like many friends and family members announce the pending arrival of a baby during the fall and winter months? That’s not exactly a coincidence. It turns out the cold season is associated with more reproductive activity than any other time of the year. The month of December alone accounts for 9 percent of conceptions in the United States. Science is gaining a better understanding of why.

All living creatures heed an evolutionary instinct to target seasonal births. If conception happens during colder months, babies will be born during warmer months, when resources will be bountiful. Northern states have births peaking in June and July, while southern states come a bit later in October and November. The farther south, the later the birth peak, since people in these warm climates are less influenced by frigid temperatures.

What are frisky humans responding to in colder months? Research suggests that the cooler temperatures and shortened days signal that it's time to get busy. Other theories suggest that men may be more fertile in colder months, or that a woman’s ovum receptivity might change with decreased daylight. Not only are couples potentially more sexually active, but that activity might wind up being more (re)productive.

Are there benefits to conceiving at other times? Possibly. One 2013 study published in the Proceedings of the National Academy of Sciences gathered data from nearly 1.5 million births and found that average birth weight in the first five months of the year decreased by 10 grams. Babies born during the summer months were 20 grams heavier. Mothers who conceived in summer tended to gain more weight than those who conceived at other times.

If you have a disproportionate amount of friends with a September birthday, it’s likely that their parents consciously or unconsciously followed their evolutionary instinct nine months earlier.

[h/t Smithsonian]

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