Capsaicin

September 13, 2004 7:55 AM

Physiologyfilter: After reading about capsaicin in this Straight Dope article by following a link from this thread, I got to thinking...

The compound has a powerful irritant effect on certain mammalian pain receptors (nociceptors). The key receptor molecule, a protein on the outer surface of the cell, was identified in 1997. When capsaicin comes into contact with it, a cascade of intracellular reactions is triggered that is perceived by the brain as pain.

People feel pain when capsaicin comes in contact with certain cells. Pain, of course, is usually the body's way of telling us that it's damaged. In the case of capsaicin, however, it's just a biophysical fluke (this molecule just happens to fit in that receptor): no harm is being done to the body, it just feels like it.

Are there other ways the body can be tricked into feeling pain when no damage is being done? Is there any danger in fooling the brain in this manner? What are the adverse affects of going through frequent or dramatic pain/endorphin cycles?

posted by Eamon to health & fitness (12 comments total)

One case that springs to mind is that of phantom limb pain, where amputee patients offer suffer severe pain that appears to come from the absence of the lost limb.
posted by adrianhon at 8:57 AM on September 13, 2004

I'm no expert but I'm betting electrical stimulation of parts of the brain or nervous system could do it.

Trying to make a gom jabbar?
posted by RustyBrooks at 10:12 AM on September 13, 2004

my gom jabbar works on psychological triggers for the illusion of pain, or the even more effective the impending threat of pain.
posted by ethylene at 10:24 AM on September 13, 2004

Capsaicin works by releasing a peptide know as substance-P from nociceptors. Release of substance-P causes pain largely by sensitizing nociceptors (reducing their threshold for activation), as well as causing edema and releasing other chemicals (such as histamine from mast cells, or serotonin from platelets) which are able to directly activate nocieptors.

Substance-P is generally only released following noxious insults to the skin, but anything that stimulates the release of substance-P or any other agent that activates or sensitizes nociceptors has the ability to produce pain in the absence of physical injury.

Capsaicin is actually applied chronically by many people suffering from neuralgias and rheumatoid arthritis (generally as a topical cream with 0.075% capsaicin or less). Although applying capsaicin the first several times is rather painful, repeated frequent application of capsaicin causes a reduction in substance-P levels, and thus reduces pain.
posted by trident at 11:01 AM on September 13, 2004

Oh, and RustyBrooks is correct, pain can readily be produced through electrical stimulation. A number of methods have actually been developed to treat pain through electrical stimulation of nocieptors (very similar to TENS, although TENS uses high frequency, low intensity stimulation, whereas the “pain” stimulation methods use low frequency, high intensity stimulation to access a specific type of nociceptor). Most people find this type of stimulation rather unpleasant, and many people are unable to tolerate it for more than a few minutes. This type of stimulation is however generally more effective and longer lasting than conventional TENS, presumably working by blockading ascending nociceptive input to the brain or by causing the release of endogenous opioids.
posted by trident at 11:18 AM on September 13, 2004

eeuuuhh
there is something profoundly disturbing about electricity. it can cause permenant damage in many ways, effectively "burning" new pathways and nerve reaction patterns. it would be kinder to jab them with needles, unless it was refined enough to create a field above a nerve center just enough to trigger the reaction.

suddenly i'm disturbed.
much in the way watching torture is far worse is fear of pain--

this reeks of tourture tips. i'm outie
(how the mind does wander)
posted by ethylene at 12:08 PM on September 13, 2004

> this reeks of tourture tips.

That's definitely one of my concerns: I wouldn't be surprised to find police departments and military organizations using capsaicin during interrogations. I'm also interested in ontological issues raised when confronting the validity of our feelings (is "pain" really just a chemical reaction?). I've also wondered if it would be possible to "feel pain" without it actually hurting: it would be awesome to maintain reflex response and awareness of stimulus without feeling real discomfort.

However, the primary motivation for posting the question is pretty simple... I like really spicy food, often to the point where it's actually painful. Maybe it's the endorphins, or maybe I'm a masochist, but either way, I want to make sure I'm not doing permanent damage to my mouth or brain.
posted by Eamon at 12:32 PM on September 13, 2004

chilis and horseradish are both very good for you, i woudn't worry so much except you are going to change the way your mouth feels until the new cells come in, so foods and sensations might feel a little blunter depending on your mouth. they are kind of addictive.

but one can be aware of pain and not effective, mentally or chemiically.
for instance, a woman's pain threshhold extends to 1000x during orgasm
posted by ethylene at 12:43 PM on September 13, 2004

Are there other ways the body can be tricked into feeling pain when no damage is being done?

You could always fall in love.
posted by Faze at 12:43 PM on September 13, 2004

oops, hit button.
btw, once got raw scotch bonnet under my eyes.
so not fun
posted by ethylene at 12:44 PM on September 13, 2004

oh but what damage...
posted by ethylene at 12:45 PM on September 13, 2004

"this reeks of tourture tips"

Don't be so provincial. Lots and lots of people out there have pretty pervy interests when behind closed doors. The ability to create pain without lasting damage is a valuable skill, both in amateur and professional practice.

For example, go and google "figging" for examples using fresh ginger. I'd provide links, but I am at work. While I don't necessarily like my job much, I do value it.
posted by Irontom at 5:07 AM on September 14, 2004