Gut Feelings: The “Second Brain” in Our Gastrointestinal Systems | Hacker News Reader

Gut Feelings: The “Second Brain” in Our Gastrointestinal Systems

scientificamerican.com

75 pointswalterbell19 comments

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.

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-...

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

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".

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.

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.

Hmm, what about charging ? I think there was something about a bit complex control of current when plugged-in. That may explain the need for more transistors (maybe not a full fledge OS but ...)

> 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/

On the topic of processing power where you wouldn't expect it, Macbook chargers contain a 16-bit TI processor (MSP430), which seems like overkill. (This is separate from the switching power supply control chip and the power factor correction chip.) I believe the TI chip handles the fairly complex startup sequence of the power supply as well as detecting faults. It's basically the equivalent of a minicomputer in your charger.

It's ubiquitous nowadays, see : http://hackaday.com/2013/08/02/sprite_tm-ohm2013-talk-hackin...

[multiple] arm cpu as hdd controller.

The Von Neumann architecture is changing.

Previous closely-related submissions:

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

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

(6 months ago) https://news.ycombinator.com/item?id=8527114 -> http://neurosciencestuff.tumblr.com/post/38271759345/gut-ins...

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

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

There was a programme on BBC radio several years ago called "The Heart Has Its Reasons" that stated the heart itself contains neurons. They interviewed a heart transplant recipient who claimed he could sense the birthday of the donor through his new heart.

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.

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

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.

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

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

http://mshop.nationalgeographic.com/html/catalog/photogaller...

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