pain

viceroy at bellsouth.net viceroy at bellsouth.net
Tue May 24 12:07:24 EDT 2005


I have forgotten the second word of the limerick, but Ken will supply it:

A - - faith healer of Deal
Remarked, "Although pain is not real,
When I sit on a pin and it punctures my skin,
I dislike what I fancy I feel."

It's the "fancy" that we like to think insects lack. 
We see them avoiding "pain" and pursuing "pleasure" and, for some of us, a filigree of emotion adds itself to the equation. 

I think the real question, hinted at by Ron, is, "does it matter if we hurt insects."
The answer then would surely be based on whether it matters if we hurt people, higher animals, "vermin", etc. on a sliding scale until we reach the protozoa ... and one remembers affectionately the image of the scientist taking his little scoop of pond water back outside, and replacing the amoebae and so forth carefully in the pond. 
It may not matter to them, but it matters to us. 

The examples you've proposed often come with a yes-but. Insects lose a leg and go galloping on, but they have break-away legs designed for this. A lizard that drops his tail may manifest humiliation,  but not pain ... it would get in the way of what it has to do. 
That's true, as well, of the praying mantis. His priority is the mating, and that's paramount.
I, too, have had the pleasure of a major wound followed by that very useful shock. There is no pain; one is able to deal with one's own first-aid, chat with helpers etc. They tried to make me lie down, but I refused, since it was a deep knee wound, and if the knee capsule is penetrated and the rescuers screw up, that's all she wrote for that knee. While I was erect, I was in charge. If I lay down, the wound would have me. 
Coumadin damage has left me with peripheral neuropathy, so I get to enjoy pain and other sensations turning off and on at random. One is obliged to be very wary of damage, since the usual sensors do not fire reliably. 

Getting back to the bugs, I think their behavior indicates that they would prefer not to be damaged. Pain is the way our bodies motivate us to that end. I'd expect bugs to have similar tropes, and figure someone will find out how it works. Or has already found out. 
Which leaves us with the question, do we care? 
The cow that provided my lunch undoubtedly disliked the end of her journey. Come to that, the grain in the bread had other plans for its future. Ours is  a high and lonely destiny. 
And, unless Saint Martin de Porres takes action fairly soon, there is a spring trap in the future of a certain cute little rat who lives in my kitchen. I feed the animals outside, please. 
Yes, you'd think I could spare a potato when I have so many, but I prefer boarders who don't shit where they eat. 
Be that as it may ... if insects have opiate endorphins, it would seem to me that they must experience pain. One goes with the other. 
Albert Schweitzer, that's who it was with the pond water. But I still can't find that adjective. 
Anne Kilmer
Mayo, Ireland


Ken,

Insects certainly can detect and respond to heat. Not only can some thermoregulate individually (for example Bernd Heinrich's bumblebees, an example that postdates Snodgrass) but some ants and of course honey bees thermoregulate their nest and hives very precisely.

As we have all agreed from the start of this discussion, there is plenty of evidence that insects _behave_ differently than mammals when damaged. My contention is that this behavioral difference is probably due to the experience created by the integration of the incoming information in the Central Nervous System rather than due to fundamental differences in the receptor cells. I agree that the presence in vertebrates of specialized nerve fibers for transmitting serious body damage stimuli may make a difference that changes the experience of 'pain' qualitatively. But it is not absolutely convincing difference, since it is well known that insects, crustaceans and even mollusks will behave sometimes in a way that appears 'frantic' and 'panic-stricken'. And it is also true that vertebrates (including myself upon breaking a leg) often go into some state of 'shock' in which pain is experienced very differently than is normal for a vertebrate. This state of shock is partly mediated by endorphins. Insects also have opioid endorphins, that play possibly similar roles (Nunez et al 1998. Alarm pheromone induces sress analgesia via an opioid system in the Honeybee. Physiology and Behavior 63: 75-80). It is, of course, hard to know whether an opiated bee feels 'calmer' and less 'panic-stricken'. We see the creatures as little robots, while we convince ourselves that we are 'aware'. I am not trying to belabor the philosophy of all this, but the original question was ultimately aimed at tricky epistemological problems. Or maybe it was just about whether insect neurobiologists have adopted the term 'nociceptor'. If so, my bad.

Patrick
patfoley at csus.edu

Kenelm W Philip wrote:

> Doug Yanega appears to have answered this question--but it might
> be worth adding the following quote from Snodgrass (Principles of
> Insect Morphology, 1935): "Insects are not known to have any
> specific organs for the perception of temperature, though they are
> highly responsive to temperature changes, nor are they known to
> have pain receptors or proprioceptors other than the terminal
> endings of sensory nerve fibers on the skin, muscles, and other
> tissues." (p. 512).
>
> As regards insects' ability to 'show very little outward sign of
> distress' after serious injury, consider the male praying mantis
> who continues to copulate after the female removes his head.
> This has nothing to do with pain, of course--since one can't feel
> pain without one's head--but it does indicate that insects work in
> very different ways than vertebrates...
>
> Like Doug, I have had a situation in which my ability to feel pain
> in a localized area was destroyed (for some time). This was the
> consequence of removing a wisdom tooth--a nerve was scraped
> resulting in my total inability to feel pain in part of my lower lip.
> I could feel pressure, but not pain. (I referred to this as 'iatrogenic
> leprosy'). Fortunately, this condition did not last more than a
> few months, since I was continually biting my lip by accident.
> A vague feeling of pressure was not enough to prompt me to
> instantly stop a bite.
>
>         Ken Philip
>
>
>



 
 ------------------------------------------------------------ 

   For subscription and related information about LEPS-L visit:

   http://www.peabody.yale.edu/other/lepsl 
 


More information about the Leps-l mailing list