The neuroscience behind ‘gut feelings’

Fight or flight? We've all been there. Now we have an understanding of how it works.

  • There is such a thing in neuroscience as a 'gut feeling.'
  • We don't quite know what it's saying yet, but we have an idea.
  • "Gut signals are transmitted at epithelial-neural synapses through the release of … serotonin."

Have you ever had a 'gut feeling?' That moment when you just knew? Did you ever wonder why that was? Research is starting to make inroads towards an answer.

A recent study led by Melanie Maya Kaelberer of Duke along with a team of others looked at mice to determine how the stomach communicated with the brain. Historically, it was believed that the stomach communicated with the brain indirectly — typically through something called neuropeptide signaling (peptides are like proteins but smaller; neurons use neuropeptides to communicate); however, the results from this study suggest something much more direct, much more nuanced, and a little bit more complicated.

Let's break that down — first by quoting the National Institute of Health: "Epithelial cells form barriers that separate different biological compartments in the body." They have a role in regulating what is communicated and what is carried between these different compartments.

Serotonin is a neurotransmitter. A neurotransmitter is a chemical that is released when a signal arrives from somewhere else in the body and acts as a bridge for the signal to move from one neuron to the next.

What makes the result of the study noteworthy is the fact that — in addition to neuropeptides — "further studies revealed that enteroendocrine cells activate sensory neurons within tens to hundreds of milliseconds, a time scale typical of synaptic transmission rather than neuropeptide signaling."

In other words: something arrived in the stomach and it was known, fast. Think of the speed with which your body lets you know that a fly has landed in your skin and think what it means that your body knows what's in its stomach at comparable speeds. (We know that gut bacteria responds to exercise, but this study raises an asterisk of a question all its own: how quickly does gut bacteria respond to exercise in real time?) It's hypothesized that the reason why this happens is to relay where something is in the gut and how it exists in space-time — whether it's just arrived, how it's immediately reacting to the digestive properties of the stomach, and so on.

Benjamin Hoffman and Ellen A. Lumpkin found the results intriguing, writing in a review of the study that it led them to wonder, "What are the molecular mechanisms of neurotransmitter release in enteroendocrine cells?" Who specifically mediates this synaptic transmission? And how are these neuron signals modulated in a stomach full of acid, anyway? What happens when someone has an intestinal disorder?

Perhaps the answer is already known to someone deep within the depths of their gut.

Major study: Drug overdoses over a 38-year period reveal hidden trends

It's just the current cycle that involves opiates, but methamphetamine, cocaine, and others have caused the trajectory of overdoses to head the same direction

  • It appears that overdoses are increasing exponentially, no matter the drug itself
  • If the study bears out, it means that even reducing opiates will not slow the trajectory.
  • The causes of these trends remain obscure, but near the end of the write-up about the study, a hint might be apparent
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Scientists discover ice volcanos on Ceres

Cryovolcanoes that eject ice instead of magma have been confirmed to exist on Ceres, which will help studying this formation on other planets and moons throughout the solar system.

  • Cryovolcanoes that ooze out ice instead of shooting out magma have been confirmed to exist on the asteroid Ceres.
  • Scientists believe that ice volcanoes may be prevalent throughout the solar system in places like Titan and Pluto.
  • Further research is needed to find out if they serve an important function for planetary structure and exo geological systems.

When we think of volcanoes we often picture plumes of smoke and hellfire lava. These are the molten towers from the underworld. But new research has uncovered that ice volcanoes or cryovolcanoes are also just a stone's throw away in our own solar system. We don't have to go that far to look for strange features of the universe. These mountainous giants spew ice instead of fire and are active planetary features that many moons, planets and asteroids might all possess.

Scientists recently analyzed images of Ceres, an asteroid 588 miles wide and one of the largest asteroids in our asteroid belt. NASA's dawn spacecraft flew by and found that Ceres is one of the first confirmed celestial bodies to have multiple cryovolcanoes. A large mountain structure called Ahuna Mons was first discovered in 2016 and subsequently classified as a cryovolcano.

It's estimated that Ceres forms a new cryovolcano every 50 million years. Studying this asteroid will give scientists more evidence to look for and study Europa, Titan and Pluto to see if they also have cryovolcanoes.

A paper published in Nature Astronomy detailed the findings. Scientists from the project stated:

"Ceres is the only plausibly cryovolcanic world to be orbited by a spacecraft up to now."

Science of a cryovolcano 

Researchers behind the study looked at images taken by the spacecraft's onboard camera. They searched for any exo geological features that were dome shaped and larger than 10 kilometers in diameter. Scientists found and measured 22 of these features and found that these domes were composed of 50 percent of ice. On further analysis, it was found that on average these cryovolcanoes on Ceres spewed out roughly 10 thousand cubic meters per year of ice.

It was determined that a cryovolcano on Ceres doesn't serve an important function say compared to volcanic activity on Earth. But that doesn't rule out that other planet's with cryovolcanoes might be function as an important part to the geological pressures and planetary structural systems.

There were some limitations to the study, as this was all researched through pictures and there wasn't an on the ground rover or robotic presence. Also the scientists weren't able to get a real time reading of the amount of activity each cryovolcano produced.

Cryovolcano on Pluto? Maybe.

Planetary scientist Michael Sori, utilized calculations made from observations and simulations to uncover the mystery about Ceres's cryovolcanoes. His theory was that since Ceres is both made out of predominantly rock and ice, the formations on the planet flow and move due to their own weight – similar to how glaciers operate on Earth. The ice flows would then be affected by slight temperature variations throughout the asteroid.

Sori said:

"Ceres' poles are cold enough that if you start with a mountain of ice, it doesn't relax… But the equator is warm enough that a mountain of ice might relax over geological timescales."

It was observed through simulation with the set parameters that cryovolcanoes on the poles would remain frozen while places in the equator and other latitudes, a cryovolcano would begin to steepen and also grow rounder over time.

Volcanic eruptions on Ceres are much more subdued than what you'd see on Earth. They do not explode, but rather ooze. This output of ice, rock and other chemicals slowly seeps from the openings out onto the rest of the asteroid.

Further research will help yield answers to determine if other suspected formations on other planets and moons may also be cryovolcanoes. After scientists from NASA's New Horizons mission stitched together a high resolution color view of Pluto, it was thought that an area known as Wright Mons may be a cryovolcano. At 150 kilometers across and 4 kilometers high, it'd be one of the largest in the far reaches of the solar system – proving that this phenomenon is not rare

Are there any cryovolcanoes on earth?

There are no cryovolcanoes on earth. The material that erupts out of these formations is either in the form of an icy liquid or gas. Earth simply is too warm for this type of formation to occur, even in the deepest reaches of Antarctica or Greenland, it wouldn't be possible. The higher surface temperature on Earth combined with its thick atmosphere makes it unable to freeze volatiles that would include Nitrogen, Methane and carbon dioxide for example.

Overall, the processes on other astral bodies make them more conducive spots for hosting a cryovolcano.

How a huge, underwater wall could save melting Antarctic glaciers

Scientists think constructing a miles-long wall along an ice shelf in Antarctica could help protect the world's largest glacier from melting.

  • Rising ocean levels are a serious threat to coastal regions around the globe.
  • Scientists have proposed large-scale geoengineering projects that would prevent ice shelves from melting.
  • The most successful solution proposed would be a miles-long, incredibly tall underwater wall at the edge of the ice shelves.

The world's oceans will rise significantly over the next century if the massive ice shelves connected to Antarctica begin to fail as a result of global warming.

To prevent or hold off such a catastrophe, a team of scientists recently proposed a radical plan: build underwater walls that would either support the ice or protect it from warm waters.

In a paper published in The Cryosphere, Michael Wolovick and John Moore from Princeton and the Beijing Normal University, respectively, outlined several "targeted geoengineering" solutions that could help prevent the melting of western Antarctica's Florida-sized Thwaites Glacier, whose melting waters are projected to be the largest source of sea-level rise in the foreseeable future.

An "unthinkable" engineering project

"If [glacial geoengineering] works there then we would expect it to work on less challenging glaciers as well," the authors wrote in the study.

One approach involves using sand or gravel to build artificial mounds on the seafloor that would help support the glacier and hopefully allow it to regrow. In another strategy, an underwater wall would be built to prevent warm waters from eating away at the glacier's base.

The most effective design, according to the team's computer simulations, would be a miles-long and very tall wall, or "artificial sill," that serves as a "continuous barrier" across the length of the glacier, providing it both physical support and protection from warm waters. Although the study authors suggested this option is currently beyond any engineering feat humans have attempted, it was shown to be the most effective solution in preventing the glacier from collapsing.

Source: Wolovick et al.

An example of the proposed geoengineering project. By blocking off the warm water that would otherwise eat away at the glacier's base, further sea level rise might be preventable.

But other, more feasible options could also be effective. For example, building a smaller wall that blocks about 50% of warm water from reaching the glacier would have about a 70% chance of preventing a runaway collapse, while constructing a series of isolated, 1,000-foot-tall columns on the seafloor as supports had about a 30% chance of success.

Still, the authors note that the frigid waters of the Antarctica present unprecedently challenging conditions for such an ambitious geoengineering project. They were also sure to caution that their encouraging results shouldn't be seen as reasons to neglect other measures that would cut global emissions or otherwise combat climate change.

"There are dishonest elements of society that will try to use our research to argue against the necessity of emissions' reductions. Our research does not in any way support that interpretation," they wrote.

"The more carbon we emit, the less likely it becomes that the ice sheets will survive in the long term at anything close to their present volume."

A 2015 report from the National Academies of Sciences, Engineering, and Medicine illustrates the potentially devastating effects of ice-shelf melting in western Antarctica.

"As the oceans and atmosphere warm, melting of ice shelves in key areas around the edges of the Antarctic ice sheet could trigger a runaway collapse process known as Marine Ice Sheet Instability. If this were to occur, the collapse of the West Antarctic Ice Sheet (WAIS) could potentially contribute 2 to 4 meters (6.5 to 13 feet) of global sea level rise within just a few centuries."

DIY electrical brain stimulation is a worrying new trend

There's still a lot even doctors don't know about it.

  • Scientists are experimenting with applying electrical current to brains as a potential therapy and enhancement.
  • A wave of DIY brain-shocking is worrying experts.
  • Would you ever zap your own brain to see what happens? DIY and direct-to-consumer devices are available, but researchers have called for an open dialog with the DIY community about the risks.
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