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.

Tesla introduces new Model 3 at $45,000

The new version's battery has a shorter range and a price $4,000 lower than the previous starting price.

Tesla Model 3 (Photo: Tesla)
Technology & Innovation
  • Tesla's new version of the Model 3 costs $45,000 and can travel 260 miles on one charge.
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What is kalsarikänni? The Finnish art of being "pantsdrunk"

Drinking home alone in your underwear just might be what you need to be as relaxed as the Finnish.

Big Think art department / Finnish tourism department
Personal Growth
  • Päntsdrunk is the latest trend to come out of Northern Europe and it involves drinking alone at home.
  • Finnish writer Miska Rantanen outlines the philosophy in his newest book titled: Pantsdrunk: Kalsarikanni: The Finnish Path to Relaxation.
  • Kalsarikänni is a word in Finnish that literally means "drinking at home and alone in your underwear."
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The surprising psychology of sex with your ex

We all know sleeping with your ex is a bad idea, or is it?

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Sex & Relationships
  • In the first study of its kind, researchers have found sex with an ex didn't prevent people from getting over their relationship.
  • Instead of feeling worse about their breakup after a hookup, the new singles who attempted sexual contact with their ex reported feeling better afterwards.
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Yes, Mega Millions just passed $1 billion. What does that look like?

It's hard to imagine such a number. But these images will help you try.

https://commons.wikimedia.org/wiki/File:Megamillions_tickets.jpg
News/Social

The Mega Millions lottery just passed $1 billion for tonight's drawing.

What does that even look like, when represented by various currencies?

It takes just 6 numbers to win. You can only, however, purchase tickets up until 10:45 ET tonight.

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Denmark has the flattest work hierarchy in the world

"It's about having employees that are empowered."

Photo by rawpixel on Unsplash
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Denmark may be the birthplace of the Lego tower, but its workplace hierarchy is the flattest in the world.

According to the World Economic Forum's Global Competitiveness Report 2018, the nation tops an index measuring "willingness to delegate authority" at work, beating 139 other countries.

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Single algae cells can help deliver targeted medicine

Tiny and efficient, these biodegradable single cells show promise as a way to target hard-to-reach cancers.

Credit: O. Yasa et al./Adv. Mater.
Surprising Science
  • Scientists in Germany have found a potential improvement on the idea of bacteria delivering medicine.
  • This kind of microtargeting could be useful in cancer treatments.
  • The microswimmers are biodegradable and easy to produce.

Metin Sitti and colleagues at the Max Planck Institute in Germany recently demonstrated that tiny drugs could be attached to individual algae cells and that those algae cells could then be directed through body-like fluid by a magnetic field.

The results were recently published in Advanced Materials, and the paper as a whole offers up a striking portrait of precision and usefulness, perhaps loosely comparable in overall quality to recent work done by The Yale Quantum Institute. It begins by noting that medicine has been attached to bacteria cells before, but bacteria can multiply and end up causing more harm than good.

A potential solution to the problem seems to have been found in an algal cell: the intended object of delivery is given a different electrical charge than the algal cell, which helps attach the object to the cell. The movement of the algae was then tested in 2D and 3D. (The study calls this cell a 'microswimmer.') It would later be found that "3D mean swimming speed of the algal microswimmers increased more than twofold compared to their 2D mean swimming speed." The study continues —

More interestingly, 3D mean swimming speed of the algal microswimmers in the presence of a uniform magnetic field in the x-direction was approximately threefolds higher than their 2D mean swimming speed.

After the 2D and 3D speed of the algal was examined, it was then tested in something made to approximate human fluid, including what they call 'human tubal fluid' (think of the fallopian tubes), plasma, and blood. They then moved to test the compatibility of the microswimmer with cervical cancer cells, ovarian cancer cells, and healthy cells. They found that the microswimmer didn't follow the path of bacteria cells and create something toxic.

The next logical steps from the study include testing this inside a living organism in order to assess the safety of the procedure. Potential future research could include examining how effective this method of drug delivery could be in targeting "diseases in deep body locations," as in, the reproductive and gastrointestinal tracts.