Scientists Discovered a New Human Brain Cell

Scientists often use mice and other animals as proxies to study human health and behavior. But this week, researchers found a mysterious new kind of brain cell that has never been seen in mice.

They called them rosehip neurons, because they have “a unique shape characterized by compact, very bushy-appearing branches that extend from the cells,” Rebecca Hodge, one of the authors of the paper, says. (It kind of looks like a rose with its petals fully open.)

They found these cells in the outermost layer of the cerebral cortex, and the rosehip neurons are believed to be an inhibitory neuron—a neuron that blocks the activity of other neurons. Hodge says it has distinctive firing properties, and expresses a particular combination of genes that set it apart from other cell types in the brain. When they looked for similar or corresponding gene expression in a mouse’s brain, they couldn’t find it.

It could be that the rosehip neuron performs a function that’s uniquely human. The researchers next step will be looking for it in other parts of the brain. "Our brains are not just enlarged mouse brains," said Trygve Bakken, an author on the study, says in a press release. "People have commented on this for many years, but this study gets at the issue from several angles."

Does this mean we shouldn’t use mice to study human brain disorders? Hodge thinks that mice are still a useful model to understand the basic function of the brain and how it works. “However, our finding of a cell type present in human brain but absent from mouse brain points to the need to study species that are more closely related to humans and to examine the human brain directly,” she says.

The promise of intermittent fasting—in which you restrict the number of hours you eat per day—is that is can help with weight loss without going on a super strict diet. A new study in theJournal of Nutritional Sciences looked at what would happen if people changed their meals times by only 90 minutes—they delayed their breakfast by 90 minutes, and ate dinner 90 minutes earlier. They did this for 10 weeks, and turned in diet diaries and blood samples, and a control group who didn’t change their meal times did the same.

The people in the study weren’t asked to adhere to any kind of diet, and could essentially eat whatever they wanted: as long as they stuck to the 90-minute adjustments. They found that the people who changed their eating times lost more than twice as much body fat as the controls. This might be explained simply by the fact that the meal adjustments led people to eat less food overall.

“57 percent of participants noted a reduction in food intake either due to reduced appetite, decreased eating opportunities or a cutback in snacking (particularly in the evenings),” a press release says. Still, it could be a relatively low-effort way to help combat obesity-related disease, if it can be shown to be effective in larger sample sizes.

Could you do it? Over half of the study's participants said they couldn't keep it up, because it didn't match up with their social or family life.

Cannabidiol, or CBD, is a non-psychoactive compound from cannabis—it comes from weed, but it won’t get you high. People are trying to use it for a wide variety of disorders, from anxiety to epilepsy, and a new study tested its ability to reduce symptoms of psychosis.

Researchers at King’s College London looked at CBD’s effect on 33 people with upsetting psychotic symptoms—who hadn’t yet been diagnosed with psychosis—and 19 controls. Around half of the participants got a single dose of CBD, while the others got a placebo. Then, they put everyone in an MRI to look at their brain activity in regions that are known to be involved in psychosis.

They found that the people experiencing psychotic symptoms had abnormal activity compared to the healthy subjects, but that the ones who had taken CBD had brain activity closer to a healthy brain. It suggests that “cannabidiol can help re-adjust brain activity to normal levels,” a release says. Interestingly, past research from King’s College found that CBD works in opposite ways than tetrahydrocannabinol, or THC—the compound in weed that gets you high. “THC can be thought of as mimicking some of the effects of psychosis, while cannabidiol has broadly opposite neurological and behavioral effects,” the press release notes.

With their results, the researchers are beginning a multi-million dollar trial to see if CBD can help young people who are at risk for developing psychosis.

New research from Emory University suggests that we can worry about what others are thinking about us as early as 24 months old. It was previously thought that this behavior developed around 4 or 5.

In the study, scientists taught children between 14 and 24 months how to use a robot toy, and then watched them play with it (with a neutral expression) or looked away and read a magazine. When the child was being watched, they showed “significantly more embarrassment,” and inhibition, the paper says. In further experiments, they found that children would use toys that adults expressed positive reactions to, and would do so more when the adult was watching. It means that the kids were paying attention to what the adult thought was good or bad, and then behaving accordingly.

“Our concern for reputation is something that defines us as human. We spend resources on make-up and designer brands, are terrified to talk in front of an audience and conform to many of society's standards because we are concerned with how others will evaluate us," lead researcher Sara Valencia Botto said in a press release. "We believe our findings get us closer to comprehending when and how we become less or more sensitive to other people's evaluation, and it reinforces the idea that children are usually smarter than we might think."

Naked mole rats behave kind of like bee or wasp colonies: A single queen does the baby-making with just a few lucky males, while the rest of the naked mole rats are workers. They look for food, maintain the nest, and many of the non-queen females help take care of the queen’s babies.

This is called “alloparental behavior” says Kazutaka Mogi, a biologist from Azabu University, and an author of a new study on naked mole rats. It’s when a mammal provides parental care to offspring that isn’t its own. Usually, when a mammal takes care of a baby, this behavior is triggered by hormones. These hormones can come from pregnancy or, in mice that Mogi has previously studied, from social behaviors that releases hormones like estrogen.

But the non-queen, or "subordinate," naked mole rat females that care for the babies are reproductively suppressed. This means that their ovaries don’t fully mature and they can't produce same levels of those hormones. What’s driving them to be nannies to babies that aren’t their own?

The answer lies in coprophagy, a delightful new word I’ve learned, which is the act of eating someone else’s poop. When a subordinate naked mole rat eats the queen’s poop—which is higher in hormones when the queen is pregnant and postpartum—she increases her levels of the hormone estradiol, which leads to mom-like behaviors. The poop-eating naked mole rats will then respond to pup’s crying, nurse them, and groom them.

At this time, naked mole rats are the only mammals known to induce parental behaviors through the eating of another’s poop. When I asked Mogi what might happen if a human woman ate another pregnant human woman’s feces (could we achieve the same thing?) he says, “Steroid hormones such as estrogen can be absorbed when humans eat those. I do not know exactly what would happen next.”

The Meat Cleanse by James Hamblin in The Atlantic.
Hamblin discusses the psychological power of food restriction and how its allure "may be especially strong at a time when order feels in short supply." ICYMI: Alan Levinovitz tried the meat-only diet for Tonic.

This Man Spent 30 Years Solving A Rare Bird’s Murder Mystery by Erik Vance in National Geographic
A who-dunnit, but about prairie chickens.

Why Are Some Caves Full of Shoes? By Stephen E. Nash in Sapiens.
Certain caves are found disproportionately full of well-preserved footwear, up to thousands of pairs. Come on. Now you have to know why.

The Mystery of People Who Speak Dozens of Languages by Judith Thurman in The New Yorker.
"Superlative feats have always thrilled average mortals, in part, perhaps, because they register as a victory for Team Homo Sapiens: they redefine the humanly possible…If Rojas-Berscia can speak twenty-two languages, perhaps you can crank up your high-school Spanish or bat-mitzvah Hebrew, or learn enough of your grandma’s Korean to understand her stories. "

The Heart of the Problem by The Angry Chef
This food writer has a radical argument: Your diet doesn't matter very much at all. An important rumination on why nutrition is so hard to study, and what other factors could be influencing our health.

Deleting Instagram, Installing Instagram: The Vicious Circle by Claire Friedman in The New Yorker
Did Friedman set up surveillance in my apartment and watch me as inspo for this humor piece?

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