Talk:Free nerve ending

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Article started[edit]

I've started writing this article, rather than just redirecting. It's pretty short at present, for which I apologise. - Jakew 04:00, 28 Jan 2005 (UTC)

It's a good start and it definitely has potential. I really don't know much about free nerve endings. I've downloaded a few papers that I will review later but in the meantime I've added what I could. I've looked at the sources you listed and I question a few things: 1) At this point, I don't believe FNE are actually involved in pressure detection per se. It seems that many sites interchange afferent neurons with free nerve endings. 2) I don't think there are fast/slow/etc adapting FNE. This was stated on the .dk page, but it seems to me that they are confusing slow conduction time with slow adapting. I can say from personal experience that pain does subside eventually, but I think this is handled differently by the brain (maybe downregulation or something like that). The lack of physical structure (like the reformable, jelly-filled capsule found in Pacinian and Meissner's) to support such a "system" is also a reason for my doubts. Anyway, I'll keep looking. --jag123 06:05, 28 Jan 2005 (UTC)
I like most of your changes so far.
I found a number of indications that FNEs are mechanoreceptive. They're included in the references:
  • "20-50% of Ad nociceptors normally respond to heat and mechanical stimuli, and are called mechanothermal nociceptors." ... "C-Fibers - Make up large proportion of fibers in a peripheral nerve most, perhaps all are nociceptors... - respond to noxious mechanical, thermal and chemical stimuli" [1]
  • "Only A delta fiber endings were mechanoreceptive"... [2]
  • (tests for response to pressure stimuli - this article also concludes that fast and slow adapting FNEs exist.) http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2135092&dopt=Abstract
This seems to indicate that they do detect pressure (please tell me if I'm reading this wrongly!).
There seems to be some doubt over whether all stimuli registered by FNEs is noxious. My instincts tell me that while some FNEs are nocireceptors, some are not. Obviously an encyclopaedia article needs to be based more on instincts, however; I need to look into this further. - Jakew 12:54, 28 Jan 2005 (UTC)
Additional:
  • There appears to be a "stretch sensitive" variety of FNE [3]
  • "Free nerve endings in the skin are modality specific and can detect either pain or touch or pressure or temperature" [4]
  • "Slowly Adapting Touch-Pressure Receptors -Free nerve endings - hairy & hairless skin - C fibers - Tickle & light or superficial touch" [5]
  • "Nonencapsulated Receptors - No slides available. - These receptors are free nerve endings that respond to crude touch, temperature sensations and damaging stimuli. Those receptors that are sensitive to noxious stimuli are termed nociceptors (Latin - nocere, to injure)." (seems to support my instint) [6]
Sorry to flood with links here... :-) - Jakew 13:24, 28 Jan 2005 (UTC)
No objections to date, so I'm going to include this info in the article. - Jakew 02:39, 31 Jan 2005 (UTC)

Formatting/Grouping[edit]

Since a lot of information is being accumulated, I was wondering how the page should be formatted / grouped. Should it be divided by noci, temp, mech, etc -ception or by A delta , C fibers? Jake, you probably know more about these things than I do at this point, what do you think? --jag123 03:17, 31 Jan 2005 (UTC)

Good point. It needs some thought. The title (and thus the focus) of the article is on the nerves, not the sensations, so I think it makes sense to divide by fibre (I'm using American spelling in the article for consistency - this could get confusing!) type, rather than stimulus. Once the article is fleshed (sorry for the word play) out a bit, I'd like to divide properly into sections, but I'm just amassing information at present. Can we tolerate a little disorderliness for a while while I gather info? - Jakew 03:23, 31 Jan 2005 (UTC)

This article describes a histological component. What you call sensation, I call function. Structure, function and to a lesser extent, location are all important, since one gives clues about the others. (Structure determines function is one of the global themes of biology). From a psychology / neurophysiology perspective, describing sensations becomes even more important. I don't really mind how you group the article, so long as it makes sense. But this "the title (thus the focus) ... is on the nerves, not the sensations" thing is an extremely weak argument for a biology article. --jag123 13:19, 31 Jan 2005 (UTC)

I'm sorry that you find my argument weak. I'm more at home with physics than biology, but I am willing to educate myself on any subject. Anyway, empirical science is empirical science is empirical science. Since you don't like my argument, could you suggest a better one, for whatever structure you think is appropriate? - Jakew 13:53, 31 Jan 2005 (UTC)

Relationship to clasp-knife response[edit]

In golgi tendon organ#history a new theory to explain clasp-knife response is said to have some connection with FNEs. Can we find more information about this and include it in this article and related articles? To start searching: [7]