These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Different mechanical transduction mechanisms for the immediate and delayed responses of rat C-fiber nociceptors.
    Author: White DM, Levine JD.
    Journal: J Neurophysiol; 1991 Aug; 66(2):363-8. PubMed ID: 1774578.
    Abstract:
    1. In this electrophysiological study, action potentials from single C-fibers were recorded in fine filaments teased from the rat saphenous nerve. We evaluated the effect of pharmacological agents on the responses of C-fiber mechanoheat nociceptors (C-MH; n = 53) after sustained suprathreshold and subthreshold stimuli. 2. Sustained suprathreshold mechanical stimuli elicit an immediate burst of activity that quickly adapts to a low-level firing that is maintained during the stimulus. Sustained subthreshold stimuli activate C-MHs after a delay and elicit a constant, low-level firing. 3. Gentamicin, a known suppressor of mechanosensory cell activity, blocked the initial rapid burst response to suprathreshold stimuli (n = 11) but had no effect on the adaptive low-level firing. The latency of the delayed activation of C-MHs induced by sustained subthreshold stimuli was not affected by gentamicin. 4. Sphingosine, a protein kinase inhibitor, increased the latency of the delayed activation of C-MHs (n = 7) to sustained subthreshold stimuli; phorbol 12-myristate 13-acetate (TPA), a protein kinase C activator, decreased the latency of the delayed activation of C-MHs (n = 9); and 4 alpha-phorbol, an inactive isomer of TPA, had no effect on the latency of the delayed activation (n = 7). Sphingosine, TPA, and 4 alpha-phorbol had no affect on the initial burst response induced by suprathreshold stimuli. 5. K+ channel blockers, 4-aminopyridine (n = 9) and noxiustoxin (n = 5), decreased the latency of the delayed activation of C-MHs to sustained subthreshold stimuli but had no effect on the initial burst response of C-MHs to suprathreshold stimuli.(ABSTRACT TRUNCATED AT 250 WORDS)
    [Abstract] [Full Text] [Related] [New Search]