Brain cells that aid appetite control identified
It’s rare for scientists to get what they describe as “clean” results without spending a lot of time repeating the same experiment over and over again. But when researchers saw the mice they were working with doubling their weight within a month or two, they knew they were on to something.
“About twenty years ago there was a big step forward in our understanding of obesity when researchers discovered that our appetite is controlled by a key molecule called leptin. Leptin is a hormone which is produced by our fat cells, and is delivered by the blood to the brain to signal the brain that we are full and can stop eating,” explains Dr. Maia Kokoeva who is affiliated both with McGill University and the Research Institute of the McGill University Health Centre. “But even though receptors for leptin were discovered soon after in the hypothalamus, a brain area that regulates food intake and body weight, it has remained unclear how exactly leptin is detected.”
So about four years ago, Kokoeva and her team set out to explore which brain cells might play a role in the process of leptin sensing and weight gain. The answer, it turns out, lies in the median eminence.
“Protection” and “preservation” cells in a busy place
The median eminence is a brain structure at the base of the hypothalamus. It is a bit like a busy hub or market place through which hormones and molecules of various kinds travel in both directions between the brain and the bloodstream to ensure that the body functions smoothly.
The McGill research team has now discovered that without a particular group of cells (known as NG2-glia cells) in place in the median eminence, the leptin receptors in the brain never receive the messages from the body telling it that it is sated.
“Most of the brain is a well-protected fortress, designed to shelter delicate nerve cells,” says Kokoeva. “The median eminence is outside these protections, and so can be a dangerous environment for the nerve cells that detect leptin. We think that the NG2-glia cells act to support and shelter the leptin receptor neurons, enabling them to instruct the body when to stop eating.”
Crucial role of the median eminence in weight gain
“We developed an interest in NG2-glia cells in this specific part of the brain because unlike neurons, during much of our adult lives these cells are constantly dividing and they do so most actively in the median eminence,” says Tina Djogo, a McGill doctoral student and one of two lead authors on the study which was published in Cell Metabolism. “But though these cells were first described about thirty years ago it has been difficult so far to pinpoint their exact functions in the adult brain.”
Because of their particularly high turnover in the median eminence, the researchers wondered if the NG2-glia cells might play a role in leptin sensing and therefore in appetite control. So they used a drug to kill the NG2-glia cells in the median eminence of a group of mice and then watched to see whether there was a difference in food intake. The results were stunning.
Within three days after they started to receive the medication, some of the mice dubbed “gainers” had already started to eat more compared with the control group of mice who had not received medication. And by 30 days afterwards, the weight of some of the mice had doubled - from 25 grams to around 50 grams.
“But what was most exciting to us, was that even though NG2-glia are found across the brain” explains Sarah Robins, a research associate who was also a lead author on this study, “it was only when we removed these cells from the median eminence that we saw this clear increase in body weight.”
A possible explanation for weight gain in brain tumour patients
The researchers then corroborated the role of the NG2-glia cells in the median eminence in appetite control through experiments using genetically modified mice, and also by using irradiation. This latter discovery suggested an explanation for a previously unexplained phenomenon in human brain cancer survivors.
“People who have been treated for brain tumours using radiation to block cell proliferation often become overweight,” says Kokoeva. “However, there has never been any satisfactory explanation, but our experiments in mice now suggests that the reason for this weight gain may be the loss of NG2-glia in the median eminence as a result of radiation.”
The researchers are hopeful that the identification of NG2-glia in the median eminence as crucial elements in body weight and appetite control will pave the way to new targeted anti-obesity approaches directed towards maintaining or raising the NG2-glia population in the median eminence.
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Prehistoric "girl power".
It's a familiar story to many of us: In prehistoric times, men were hunters and women were gatherers. Women were not physically capable of hunting because their anatomy was different from men. And because men were hunters, they drove human evolution. But that story's not true, according to research by University of Delaware anthropology professor Sarah Lacy, which was recently published in Scientific American and in two papers in the journal American Anthropologist. Lacy and her colleague Cara Ocobock from the University of Notre Dame examined the division of labor according to sex during the Paleolithic era, approximately 2.5 million to 12,000 years ago. Through a review of current archaeological evidence and literature, they found little evidence to support the idea that roles were assigned specifically to each sex. The team also looked at female physiology and found that women were not only physically capable of being hunters, but that there is little evidence to support that they were not hunting.
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It’s the worst
We FAILED as husbands... - Wife PC Build-Off Girls can build PCs.
I need to download and try some of these.
Keep seeing some posts circulating about popular websites and wanted to make a version for apps.
These are apps I’m way too addicted to. Am I missing any?
P.S. I’m on an iPhone so these are iPhone apps, but probably have an Android version too.
Edit: Sorry for all the time I’ve taken away from your life
Commaful - popular fanfiction, story, and poetry community 👑
Bettr - the reason my friends are jealous of my Insta
Sweatcoin - get paid to walk
Tiktok - coolest videos on the internet (top 10 app in the world)
Spellbound - addictive horror 👻 and romance stories
Helix Jump - legit the most addicting game on my phone
Calm - Award-winning app for meditation and sleeping better
Tenkyu - tilt your phone and watch the relaxing magic happen
Slime Road - bet you can’t hit the bullseye ⚾️
Hempire - become a plant mogul
Dune! - Ride the sand dunes like a baller!! so much fun
Hotspot Shield - free proxy/VPN to bypass school filters
Betternet - free proxy VPN, like Hotspot, try both and see which you prefer
Terrarium - build the ultimate garden empire
Golf Orbit - ever played golf on mars?
Sling Drift - beep beep - level 70 is insane 🚗
1Q - get paid to answer simple questions
Bee Factory - become a honey tycoon
Wind Rider - fly through a city in a wing suit
Spill it - drop balls and break glass
Fire Balls - shoot balls at obstacles. gets pretty hard
Paper - can you conquer all the territory and win?
Two Dots - a fun puzzle game. easy time killer
Planet Bomber - let’s nuke some planets
Ice Racing - race down a mountain at record speeds
Splashy - bounce the ball accurately to survive. requires focus
Snakes Vs. Blocks - even more fun than the original snake hehe
Twenty48 Solitaire - best toilet game
Knock Balls - shoot down blocks with a canon - surprisingly relaxing
Wishbone - fun game for comparing stuff like hair, celebs, sports
Hole - fuck up a city muahaha
Dosh - get paid to shop
Yarn - stories that are seriously creepy af
You’re welcome 😉
moth monster girlfriends
Mankinds constant search for free WiFi :) lol.
God, Life, Free Wifi