How anesthesia affects your brain and body

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Millions of Americans undergo anesthesia each year. Since 1846, doctors have used a variety of drugs to make patients unconscious for surgery, but even though the medications have changed, there’s one thing that remains the same— it works. But how exactly? We don’t know every detail about what’s going on when we administer anesthesia, but then again, we also don’t know exactly how consciousness works either. What we do know is that anesthesia interrupts our brain’s neural pathways so we don’t feel pain. Anesthesiologist Jill Fong explains how it works. Following is a transcript of the video. 

Narrator: When you go to sleep, if I pinched you, you’d be up. If I shook you, you’d be up, right? But under anesthesia, I’m gonna pinch you and do a full operation and you’re not up. So it’s really further on the spectrum of unconsciousness.

Narrator: When you wake up after being put under with general anesthesia you barely feel like any time has passed. You could have been out for an hour or a day and you wouldn’t know the difference.

Fong: When you go to a natural sleep, people call your name, your alarm goes off, you wake up, right? This is not what is gonna happen during general anesthesia. You’re gonna be unconscious.

Narrator: You’re closer to being in a coma than being asleep.

Anesthesia was first used during surgery in 1846. The drug provided at that time was ether. Now anesthesiologists more commonly use a combination of drugs like propofol and fentanyl which interrupt neural pathways so you don’t feel pain and you don’t remember the surgery.

Fong: Three things that you need for general anesthesia are you need amnesia so that they don’t remember, analgesia so they have pain relief and then operating conditions for the surgeon. Some surgeries you need the patient to be very relaxed so you would use a muscle relaxant. Other surgeries the patient just needs to be asleep and anesthetized but they don’t need relaxation so how they do that varies upon the different medications that you’re using. Some will depress excitatory neurons and some will enhance inhibitory neurons.

Narrator: Excitatory neurons, for example, get excited and send signals to other neurons to fire. Depressing them means less signals telling your brain you’re in pain. Inhibitory neurons do the opposite. They make it harder for neurons to generate these electrical signals. In either case this means fewer active neurons overall which is important because when your body is being poked and prodded, neurons would typically fire to tell your brain you’re in pain. If those neurons aren’t firing, your brain doesn’t know that your body is, well, being cut open.

Fong: Basically it interrupts the pathways and the communication between your neural networks. We’re aiming for them to be not in pain by looking at their vital signs, their heart rate, their blood pressure. Then we want to make sure that they’re unconscious.

Narrator: Without anesthesia, many important surgeries wouldn’t be possible because they’d be way too traumatic.

Fong: Surgery didn’t move forward, really, until anesthesia moved forward. You know, you watch those old movies. They give you a swig of alcohol, they put a tourniquet and they hack your leg off. People don’t do well with that, right? If you had a bad heart, that would be the end of that.

Narrator: After the procedure is complete the doctors stop administering the meds and the most powerful effects of the drugs wear off but even though you’re conscious again you might continue to experience some of the drugs side effects. 

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This photo of the solar coronal mass ejection shows just how small the Earth is

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Photos of space and from space never cease to amaze us. And more often than not, they remind us just how small we are. In this image of solar coronal mass ejection, we can once again see how impressive the Universe is, and just how small we are in comparison.

The image was taken by NASA’s SDO spacecraft back on 7 June 2011 and recently edited and published by Jason Major.  He explains a coronal mass ejection phenomenon:

“A coronal mass ejection (CME) the result of solar plasma caught within a loop of magnetic field from the Sun (i.e., a prominence) being blasted into space when the loop breaks.”

Some of the material falls back into the Sun but some is also sent out into the solar system.

It appears liquid but it is all ionized gas and charged particles controlled by magnetic fields and, of course, the Sun’s powerful gravitational pull.”

When you look at the image alone, it’s difficult to imagine the size of the coronal mass ejection. So, to help you get the better feeling of the proportions, there’s a small image of Earth in the upper left corner. I know it’s difficult to grasp. But it’s one of the things that make this image and other similar images so impressive.

[via Digg, image credits: Jason Major/NASA/SDO]

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Animals that defy the rules of aging — like naked mole rats — could help scientists unravel the secrets to longevity

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naked mole rat

  • Some long-living animals seem to defy the rules of aging, so scientists are studying them.
  • Two animals of interest to researchers are the naked mole rat, which lives decades longer than its rodent relatives, and turtles, which can live up to 200 years. 
  • Researchers have found noticeable differences in the ways these animals’ metabolisms and mitochondria function. 

Being a freak of nature isn’t always a bad thing, especially if you defy the conventions of aging

Naked mole rats and turtles are outliers when it comes to the rules of nature. The mole rat lives up to 31 years, decades longer than its other rodent relatives. Turtles are one of the longest-living creatures on Earth. 

Comparing the biology of these animals to others that age poorly provides valuable insights to scientists about which biological pathways are most important for longevity. That information could ultimately help them find ways to increase human lifespans. 

A cornucopia of factors are at play as a younger organism gets older: proteins get damaged, they build up and disrupt cell functions, mutations occur, and once-harmless cells turn into cancer. But the important question when it comes to aging is not how it happens, according to Richard Miller, director of the Glenn Center of Aging Research at the University of Michigan.

"The real question is what has been done across species or within a species to slow it," Miller told Business Insider.

Long live the naked mole rat

A popular theory in the field of aging is that an organism puts most of its resources — such as nutrients, energy, time and effort — either into maintaining their body or reproducing, but not both. In people, for example, women’s average lifespan decreases if they have children. Scientists believe this happens because human reproduction can cause damage to cells and deplete resources in the body that would otherwise have been used for cellular repair.

But paradoxically, breeding seems to extend the life of the naked mole rat. 

Scientists Martin Bens and Alessandro Ori at the The Leibniz Institute on Aging in Germany are working to understand this anomaly. 

Each colony of mole rats designates a queen, the same way ants do, and only she breeds and bears young. There is also only one breeding male per colony. But non-breeders can transition to become a breeder, so Bens and Ori studied that transition process. 

Their results suggested that the signal pathways involved in mole rats’ transition to breeding are also involved in their aging process.

In males, some of these overlapping pathways are related to their metabolism, the process of converting food to usable units of energy in the body. Scientists found that breeding male mole rats produced greater-than-normal amounts of energy in their testes cells, and lower-than-normal amounts in their skin cells. Diverting energy in this way could play a role in delaying the aging process. 

Naked Mole Rats

Ori and Bens also observed differences in the composition of the mole rats’ mitochondria: the small organelles in cells that power metabolic processes. They observed that the naked mole rats had a reduced mitochondria respiration rate compared to guinea pigs, which meant that the mole rats were making less energy and using less fuel and oxygen.

The researchers also found that all the naked mole rats preferred to use lipids or fats as an energy source, rather than the carbohydrates or sugars that shorter-lived rodents mostly use. 

Another factor that allows naked mole rats to live so long is their abnormally low body temperature. Lower basal body temperatures in animals are usually correlated with prolonged healthspan, and naked mole rats are mammals but aren’t warm-blooded, which makes them an anomaly in the rodent family.

Finally, Ori and Bens examined naked mole rats’ livers. Livers generally detoxify the body and eliminate chemicals that can damage cells and accelerate aging. In mole rats, these detox pathways were more active than the same systems in guinea pigs, suggesting that mole rats keep their cells healthy and undamaged from toxins more efficiently. That could also explain why they out-live their rodent cousins.

The tortoise and the human

Tortoises and turtles are masters of aging. Jonathan, a Seychelles giant tortoise, is the oldest known terrestrial animal at 186 years of age, and is going strong.

"There are tortoises until recently that knew Darwin personally," Kenneth Storey, a professor at Carleton University who studies turtles, told Business Insider.

These ancient beings are the most evolved and complex animal that can survive complete anoxia: a total absence of oxygen. Turtles can go well over a year without oxygen.

By comparison, naked mole rats can survive almost 20 minutes without oxygen, and oxygen-deprived humans only get about two minutes of brain activity and five minutes of heart activity before all systems shut down and organs become irreparably damaged.

To live without oxygen, Storey said, turtles drop their metabolism rate to next to nothing. 

"What the turtles do is in a tissue-specific manner, shut down genes and sub-cellular organelles that use energy or that need maintenance," he said.

Green sea turtle

Turtles shut their energy production off by changing an enzyme called pyruvate dehydrogenase, which turns off their mitochondria. Starving the mitochondria then forces the turtle’s body to secrete a special protein that protects cells. 

In the absence of oxygen, turtles can initiate an organized shutdown of 50,000 processes in their bodies.

"We know what happens to the pathways and we know what happens to the system, but we don’t know what ultimately controls it," Storey said.

He added that under stressful, low-oxygen conditions, turtles’ bodies do one other thing exceptionally well: "They don’t panic."

In these circumstances, turtles turn off most of their stress-response proteins so they can focus what little energy they have on reshaping their cells to operate differently in anoxic conditions. Those changes include preventing cells from digesting and turning over proteins, a process called autophagy that can make detritus and cause damage. Limiting the amount of matter created and destroyed in their bodies allows turtles to maintain a pristine internal balance. 

By comparison, human cells that are deprived of oxygen turn on stress kinases: signaling proteins that help facilitate communication in the body in order to respond to a challenging situation. Over-activating stress kinases can use up a lot of energy, overload the system, and ultimately trigger cell death.

When juxtaposing humans and turtles, Storey thinks longevity depends on an energy trade-off.

"Think of these lower animals as living longer than us because their pilot light is lower. They’re not 37 degrees [Celsius], they’re not racing around," he said. "They’re not burning the candle at both ends, they’re barely burning the candle at one end, and during anoxia they stop burning the candle. That’s how they can live so long. It’s a pace argument."

All about energy

The idea that metabolism is one of the key factors in the aging process has been a cornerstone of many studies on aging. Hypothetically, if you turned down the energy production in your cells, you could live longer and get fewer wrinkles, Storey said. But you would probably not have enough energy to sustain a normal human life.

Humans’ complexities mean we require more energy and a constant supply of oxygen to power our cells. We also need to consume food frequently to fuel our bodily functions.

"What we’ve opted for is a high velocity lifestyle, which ties us in to oxygen all the time," Storey said. 

Rozalyn Anderson, an associate professor at the University of Wisconsin School of Medicine and Public Health, told Business Insider that it’s hard to ignore how big a role metabolism and energy balance play in aging. Anderson studies caloric restriction in monkeys, and said evidence is starting to show that age-related diseases show up with increased prevalence in people who have metabolic issues and obesity.

"I think it’s all about energy: energy use, energy storage, and the type of pathways that are being engaged to derive energy," Anderson said.

SEE ALSO: A new documentary chronicles the lives of triplets separated at birth in a controversial study — here’s how scientists continue to use twins in research

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NOW WATCH: Why wrinkles form as we age

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This robot maintains tender, unnerving eye contact

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Humans already find it unnerving enough when extremely alien-looking robots are kicked and interfered with, so one can only imagine how much worse it will be when they make unbroken eye contact and mirror your expressions while you heap abuse on them. This is the future we have selected.

The Simulative Emotional Expression Robot, or SEER, was on display at SIGGRAPH here in Vancouver, and it’s definitely an experience. The robot, a creation of Takayuki Todo, is a small humanoid head and neck that responds to the nearest person by making eye contact and imitating their expression.

It doesn’t sound like much, but it’s pretty complex to execute well, which, despite a few glitches, SEER managed to do.

At present it alternates between two modes: imitative and eye contact. Both, of course, rely on a nearby (or, one can imagine, built-in) camera that recognizes and tracks the features of your face in real time.

In imitative mode the positions of the viewer’s eyebrows and eyelids, and the position of their head, are mirrored by SEER. It’s not perfect — it occasionally freaks out or vibrates because of noisy face data — but when it worked it managed rather a good version of what I was giving it. Real humans are more expressive, naturally, but this little face with its creepily realistic eyes plunged deeply into the uncanny valley and nearly climbed the far side.

Eye contact mode has the robot moving on its own while, as you might guess, making uninterrupted eye contact with whoever is nearest. It’s a bit creepy, but not in the way that some robots are — when you’re looked at by inadequately modeled faces, it just feels like bad VFX. In this case it was more the surprising amount of empathy you suddenly feel for this little machine.

That’s largely due to the delicate, childlike, neutral sculpting of the face and highly realistic eyes. If an Amazon Echo had those eyes, you’d never forget it was listening to everything you say. You might even tell it your problems.

This is just an art project for now, but the tech behind it is definitely the kind of thing you can expect to be integrated with virtual assistants and the like in the near future. Whether that’s a good thing or a bad one I guess we’ll find out together.

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Wyre Adds MakerDAO Stablecoin Pairing for Global Money Transfers

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MakerDao

Under the new framework, Wyre’s regulated money transfer infrastructure will be used to facilitate the instantaneous movement of “fiat currency directly into and out of Dai,” thereby removing the unpredictability of “speculative cryptocurrencies like Ethereum and Bitcoin” and benefiting from the speed and security of the blockchain, a press release for the announcement states. The arrangement is designed to give customers a quick and secure money transfer protocol that offers full regulatory compliance.

“Pairing Dai to Wyre’s trading engine and global fiat on-ramps and off-ramps will enable nearly-instant movement of funds across borders. By decreasing the amount of time it takes to clear payments, businesses can increase the number of payment cycles, therefore increasing revenue. Remittance platforms or crypto services can also settle instantly in Dai rather than using international wires which can take up to 48 hours,” the release continues.

Through the partnership, Wyre now offers prospective users an Access Point Interface (API) to connect their bank accounts to the blockchain through Dai, while taking care of KYC/AML compliance and onboarding concerns. Using the API, users can now trade Dai against many of the world’s major fiat currencies and cryptocurrencies including USD, GBP, EUR and more.

Speaking with Bitcoin Magazine, Rune Christensen, CEO of MakerDAO, said the alliance would be beneficial to API developers who can leverage Wyre’s experience as a regulated money service business and focus on creating access from local currency to Dai to fulfill global transactions.

“Through this partnership, we are now helping API developers leverage Wyre’s experience in banking and compliance so they can take advantage of the stability of Dai stablecoin to build and engage their communities, cutting through the red tape, and leaving the off-chain complications to a regulated money services business,” he stated.

“As it relates to the supply chain, organizations that may have been hesitant to engage in crypto transactions can now go directly from fiat currency into Dai stablecoin without having to take the middle step of converting fiat to ETH and then to Dai.”

For his part, Wyre CEO Michael Dunworth indicated that the partnership offers users around the world a cost-effective means of breaking through bureaucratic red-tape in a compliant manner. In his own interview with Bitcoin Magazine, he said, “We’re committed to developing partnerships with leaders like MakerDAO to enable the blockchain ecosystem to evolve at a faster pace.”

Since its launch in 2017, Dai has maintained its advertised USD valuation, which has earned it the respect and esteem of the crypto community. Unlike other popular stablecoins like Tether and TrueUSD, which are backed by fiat, Dai is crypto-collateralized, backed by coins like ether and bitcoin.

This article originally appeared on Bitcoin Magazine.

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