[Neuroscience] Re: 'Adapting' to pain [Theoretical]

Brian.D.Duryee briandd at broadpark.no
Tue Jan 3 10:42:59 EST 2006


Thanks. Wasn't thinking of the psychological state of mind.

B

"Matthew Kirkcaldie" <m.kirkcaldie at removethis.unsw.edu.au> skrev i melding 
news:m.kirkcaldie-C96B18.10052331122005 at un-2park-reader-01.sydney.pipenetworks.com...
> In article <1135910939.530414.164550 at g14g2000cwa.googlegroups.com>,
> "Radium" <glucegen1 at excite.com> wrote:
>
>> Hi:
>>
>> The sensation of pain is due to stimulation of the nociceptors.
>
> This is not really correct - pain is a psychological state, an
> interpretation of sensory information as distressing or damaging.
> Nociceptors are often linked to the mind-state of pain, and usually
> signal damage to the body, but they don't produce the sensation of pain.
> Nociceptors can be activated in ways that are not painful (e.g. enjoying
> chilli in food, or people who find "pain" sexually arousing) and you can
> also produce pain states without activating nociceptors - for instance
> if you try to eliminate chronic pain by removing the nociceptors, the
> sensation of pain can be reproduced or even enhanced by the remaining
> parts of the system.  You can also produce a vivid, painful burning
> sensation in the skin by touching a surface with closely alternating
> warm and cold parts, without ever activating a nociceptor.
>
>> Stimulating a greater amount of nociceptors per area results in a
>> stronger sensation of pain than stimulating a smaller amount of
>> nociceptors per area.
>
> Again, not really true.
>
>> However, individuals who have been exposed to
>> pain over a greater period of time have a greater threshold of pain.
>> The brain has gone through sensory fatigue. Thus, more nociceptors per
>> area need to stimulated [than previously] to induce the same
>> *perceived* intensity of pain.
>
> I would strongly disagree with this as well.  Do you have any evidence?
> The key aspect of pain is that it is a sensation which does NOT adapt,
> since it normally signals damage and danger, which are things we don't
> want to become used to.
>
>> I wonder if the sensation of pain could be alleviated by the following.
>>
>> Lets say that initally, a small amount of nociceptors per area were
>> stimulated in all regions of a subject's body. Initially the amount of
>> nociceptors per area that excited are too small to produce pain.
>
> A single nociceptor will generally produce a noxious sensation if
> stimulated on its own.  And how are you proposing to stimulate
> nociceptors exclusively?  If you're going after them electrically you
> can't stimulate them without stimulating other sensory fibres; other
> nociceptor-specific stimuli are, well, PAINFUL!  They're usually
> chemicals knoiwn as algogens, meaning pain-creators, and may include
> bradykinins, potassium solutions, histamines, etc.
>
>> However, as time progress, more and more nociceptors per area are
>> stimulated. The increase in number of stimulated nociceptors increases
>> very slowly over a long period of time. After a long period of time
>> passes by, then the subject has each and every nociceptor in his/her
>> body stimulated. The subject's nociceptors are completely stimulated
>> for the rest of his/her life.
>
> Not practical, but it would be irreducibly, non-adaptingly,
> excruciatingly painful if it was.
>
>> Would the subject become totally resistant to the sensation of pain?
>
> No.
>
> However there are stimulatory approaches which seek to dilute or mask
> the sensation of pain by flooding other sensory channels - have a look
> at transcutaneous electrical nerve stimulation (often abbreviated TENS).
>
> Nice ideas but you need to look at the basics a little more closely!
>
>         MK. 




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