Lawson SN
Experimental physiology. Date of publication 2002 Mar 1;volume 87(2):239-44.
1. Exp Physiol. 2002 Mar;87(2):239-44.
Phenotype and function of somatic primary afferent nociceptive neurones with C-,
Adelta- or Aalpha/beta-fibres.
Lawson SN(1).
Author information:
(1)Department of Physiology, School of Medical Sciences, University Walk, Bristol
BS8 1TD, UK. sally.lawson@bristol.ac.uk
Nociceptive dorsal root ganglion (DRG) neurones have fibres that conduct in the
C, Adelta and Aalpha/beta conduction velocity range. The properties of
nociceptive compared with non-nociceptive somatic afferent dorsal root ganglion
neurones appear to fall into two patterns, A and B. Pattern A properties of
nociceptive neurones, the more common type, include longer action potential
duration and slower maximum rate of fibre firing, as well as a greater expression
of substance P and calcitonin gene-related peptide immunoreactivity. The values
of pattern A properties appear to be graded according to the conduction velocity
group (C, Adelta or Aalpha/beta) of the fibres. The most pronounced forms of
A-type properties are expressed by nociceptive neurones with C-fibres, and these
become less pronounced in nociceptive neurones with Adelta-fibres and least
pronounced in those with Aalpha/beta fibres (C > Adelta > Aalpha/beta). Some of
these properties are also expressed in a less extreme but similarly graded manner
through C, Adelta and Aalpha/beta groups of non-nociceptive low threshold
mechanoreceptive (LTM) neurone. The less common pattern B properties of
nociceptive neurones have similar values in C-, Adelta- and Aalpha/beta-fibre
nociceptive neurones but these clearly differ from LTM units with C-, Adelta- and
Aalpha/beta-fibre conduction velocities. These features of nociceptive neurones
include consistently larger action potential overshoots and longer
after-hyperpolarisation durations in nociceptive than in LTM neurones.
PMID: 11856969 [Indexed for MEDLINE]
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