

Gut Feelings: The “Second Brain” in Our Gastrointestinal Systems - walterbell
http://www.scientificamerican.com/article/gut-feelings-the-second-brain-in-our-gastrointestinal-systems-excerpt/

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cel1ne
This maps nicely to the two separate locations where the body produces most
serotonine: In the gut and in the brain. (Serotonine isn't able to cross the
blood-brain-barrier).

There are even two different genes TPH1 and TPH2 which encode the enzyme
information for this. This split is apparently very old and evolved before
vertebrates did.

This is also why SSRIs have so many side-effects. They target receptors in the
brain, but at the same time jumble serotonine-levels in the body, which are
involved in appetite, temperature, blood-pressure, day/night cycle and many
other systems.

~~~
normous
Interestingly enough, Caltech just released a study last month that shows that
gut microbes directly help produce serotonin in the gut:

[http://www.caltech.edu/news/microbes-help-produce-
serotonin-...](http://www.caltech.edu/news/microbes-help-produce-serotonin-
gut-46495)

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tejohnso
Douglas Crockford has a great talk that touches on the head-gut connection and
how it relates to programming.

"We could not program without our gut. I have absolutely no evidence to
justify that statement. But my gut tells me it's true, so I believe it."

[https://www.youtube.com/watch?v=taaEzHI9xyY](https://www.youtube.com/watch?v=taaEzHI9xyY)

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geomark
That gut-brain connection is the focus of some types of meditation where you
move your center of focus from your head to the center of your body. That's
supposed to be the location of the "second brain".

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agumonkey
I thought of this when I learned that ThinkPad batteries had a complex
controller, almost a dedicated cpu with a real-time OS, to ensure safe and
consistent state of battery cell voltage and temp. Critical systems need
dedicated apparatus.

~~~
Dylan16807
The batteries don't need that. A trivial analog temperature shutoff is plenty,
and you can do cell balancing too with a handful of transistors.

~~~
ggchappell
> The batteries don't need that.

I would imagine not. But the economics of digital-equipment design can be
counterintuitive. Sure, we could put together a bit of custom hardware. But
slapping an off the shelf microcontroller in there, and writing some firmware
to run it, can be a little cheaper to design and just as cheap to build. And
then after the equipment has shipped, if we need to fix a problem -- or even
just tweak things a bit -- then our software solution is _a lot_ cheaper.

But then someone finds a security vulnerability in our battery:
[http://www.wired.com/2011/07/apple_battery/](http://www.wired.com/2011/07/apple_battery/)

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kazinator
Previous closely-related submissions:

(10 months ago)
[https://news.ycombinator.com/item?id=7957057](https://news.ycombinator.com/item?id=7957057)
-> [http://www.scientificamerican.com/article/gut-second-
brain/](http://www.scientificamerican.com/article/gut-second-brain/)

(2 months ago)
[https://news.ycombinator.com/item?id=9077837](https://news.ycombinator.com/item?id=9077837)
-> [https://www.theconnection.tv/second-brain-
gut/](https://www.theconnection.tv/second-brain-gut/)

(6 months ago)
[https://news.ycombinator.com/item?id=8527114](https://news.ycombinator.com/item?id=8527114)
-> [http://neurosciencestuff.tumblr.com/post/38271759345/gut-
ins...](http://neurosciencestuff.tumblr.com/post/38271759345/gut-instincts-
the-secrets-of-your-second-brain)

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SmallBets
As more in this field comes to light, it makes medicine's overuse (imo) of
antibiotics very concerning.

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hasenj
Is the title misleading? (genuine question)

I've read articles (mostly from religious sources) trying to say the exact
same thing about the heart (because, not surprisingly, religious texts speak
about the heart as the seat of the soul/mind).

So I'm a little skeptical of such claims

~~~
acous
It's possible that the heart is the phenomenological seat of mind for some --
either innately or culturally -- irrespective of objective anatomy. Perhaps
the problem with the religious articles is that they are being overzealous in
trying to link the two domains? To me it's a question of whether using a
biological abstraction internally is more useful than (one of) the
religious/spiritual models.

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rmah
some ancient cultures used "liver" the way we use "gut". i.e. "I felt the
anger in my liver!"

~~~
contingencies
Colloquial modern Mandarin Chinese uses a few words for the same, chiefly 肠
(cháng; to do with "intestines" or "digestive innards"), 胃 (wèi; "stomach"),
肚子 (dùzi; "belly" or "abdomen"). The former two are also sometimes mixed in to
肠胃, in which case they mean stomach. Honestly, after 15 years mostly in the
country it still amazes me how clearly people delineate between three words
for essentially the same thing, and heartily state one is correct for a given
situation, as if suddenly they meant three completely different parts of the
body (which, technically, 肠 does and 肚子 could, but in reality neither are
clear).

For instance, if one has diarrhea (a quintessentially Chinese experience),
then one has 拉肚子 ('a pulled belly'). If one has virtually any form of
digestive tract discomfort, one is 胃痛 ('stomach pain'). More formally, 肠胃炎
('gastroenteritis') is used. And yet, standing on the ground inside mainland
China, greatly animated emotional responses will assure you from all
directions that all are completely distinct conditions.

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lotsofmangos
I wonder how stuff like this will effect that scary head-transplant idea.

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eternalban
On a related note, //Mother's// Day is close at hand ..

[http://mshop.nationalgeographic.com/html/catalog/photogaller...](http://mshop.nationalgeographic.com/html/catalog/photogalleries/inthewomb/images/womb4.jpg)

